title: Integrated information theory

text: Integrated information theory (IIT) attempts to provide a framework capable of explaining why some physical systems (such as human brains) are conscious, why they feel the particular way they do in particular states (e.g. why our visual field appears extended when we gaze out at the night sky), and what it would take for other physical systems to be conscious (Are other animals conscious? Might the whole Universe be?). In principle, once the theory is mature and has been tested extensively in controlled conditions, the IIT framework may be capable of providing a concrete inference about whether any physical system is conscious, to what degree it is conscious, and what particular experience it is having. In IIT, a system's consciousness (what it is like subjectively) is conjectured to be identical to its causal properties (what it is like objectively). Therefore it should be possible to account for the conscious experience of a physical system by unfolding its complete causal powers (see Central identity).


title: Integrated information theory

text: IIT was proposed by neuroscientist Giulio Tononi in 2004. The latest version of the theory, labeled "IIT 3.0", was published in 2014. However, the theory is still in development, as is evident from the later publications improving on the formalism presented in IIT 3.0.


title: Integrated information theory

text: David Chalmers has argued that any attempt to explain consciousness in purely physical terms (i.e. to start with the laws of physics as they are currently formulated and derive the necessary and inevitable existence of consciousness) eventually runs into the so-called "hard problem". Rather than try to start from physical principles and arrive at consciousness, IIT "starts with consciousness" (accepts the existence of our own consciousness as certain) and reasons about the properties that a postulated physical substrate would need to have in order to account for it. The ability to perform this jump from phenomenology to mechanism rests on IIT's assumption that if the formal properties of a conscious experience can be fully accounted for by an underlying physical system, then the properties of the physical system must be constrained by the properties of the experience. The limitations on the physical system for consciousness to exist are unknown and consciousness may exist on a spectrum, as implied by studies involving split brain patients and conscious patients with large amounts of brain matter missing.


title: Integrated information theory

text: Specifically, IIT moves from phenomenology to mechanism by attempting to identify the essential properties of conscious experience (dubbed "axioms") and, from there, the essential properties of conscious physical systems (dubbed "postulates").


title: Integrated information theory

text: The axioms are intended to capture the essential aspects of every conscious experience. Every axiom should apply to every possible experience.


title: Integrated information theory

text: The wording of the axioms has changed slightly as the theory has developed, and the most recent and complete statement of the axioms is as follows:


title: Integrated information theory

text: The axioms describe regularities in conscious experience, and IIT seeks to explain these regularities. What could account for the fact that every experience exists, is structured, is differentiated, is unified, and is definite? IIT argues that the existence of an underlying causal system with these same properties offers the most parsimonious explanation. Thus a physical system, if conscious, is so by virtue of its causal properties.


title: Integrated information theory

text: The properties required of a conscious physical substrate are called the "postulates," since the existence of the physical substrate is itself only postulated (remember, IIT maintains that the only thing one can be sure of is the existence of one's own consciousness). In what follows, a "physical system" is taken to be a set of elements, each with two or more internal states, inputs that influence that state, and outputs that are influenced by that state (neurons or logic gates are the natural examples). Given this definition of "physical system", the postulates are:


title: Integrated information theory

text: </math>]]), thus laying maximal claim to intrinsic existence. ... With respect to causation, this has the consequence that the "winning" cause-effect structure excludes alternative cause-effect structures specified over overlapping elements, otherwise there would be causal overdetermination. ... The exclusion postulate can be said to enforce Occam's razor (entities should not be multiplied beyond necessity): it is more parsimonious to postulate the existence of a single cause-effect structure over a system of elements—the one that is maximally irreducible from the system's intrinsic perspective—than a multitude of overlapping cause-effect structures whose existence would make no further difference. The exclusion postulate also applies to individual mechanisms: a subset of elements in a state specifies the cause-effect repertoire that is maximally irreducible (MICE) within the system (formula_1), called a core concept, or concept for short. Again, it cannot additionally specify a cause-effect repertoire overlapping over the same elements, because otherwise the difference a mechanism makes would be counted multiple times. ... Finally, the exclusion postulate also applies to spatio-temporal grains, implying that a conceptual structure is specified over a definite grain size in space (either quarks, atoms, neurons, neuronal groups, brain areas, and so on) and time (either microseconds, milliseconds, seconds, minutes, and so on), the one at which formula_2 reaches a maximum. ... Once more, this implies that a mechanism cannot specify a cause-effect repertoire at a particular temporal grain, and additional effects at a finer or coarser grain, otherwise the differences a mechanism makes would be counted multiple times.


title: Integrated information theory

text: For a complete and thorough account of the mathematical formalization of IIT, see reference. What follows is intended as a brief summary, adapted from, of the most important quantities involved. Pseudocode for the algorithms used to calculate these quantities can be found at reference. For a visual illustration of the algorithm, see the supplementary material of the paper describing the PyPhi toolbox.


title: Integrated information theory

text: A system refers to a set of elements, each with two or more internal states, inputs that influence that state, and outputs that are influenced by that state. A mechanism refers to a subset of system elements. The mechanism-level quantities below are used to assess the integration of any given mechanism, and the system-level quantities are used to assess the integration of sets of mechanisms ("sets of sets").


title: Integrated information theory

text: In order to apply the IIT formalism to a system, its full transition probability matrix (TPM) must be known. The TPM specifies the probability with which any state of a system transitions to any other system state. Each of the following quantities is calculated in a bottom-up manner from the system's TPM.


title: Integrated information theory

text: For a system of formula_3 simple binary elements, cause-effect space is formed by formula_4 axes, one for each possible past and future state of the system. Any cause-effect repertoire formula_5, which specifies the probability of each possible past and future state of the system, can be easily plotted as a point in this high-dimensional space: The position of this point along each axis is given by the probability of that state as specified by formula_5. If a point is also taken to have a scalar magnitude (which can be informally thought of as the point's "size", for example), then it can easily represent a concept: The concept's cause-effect repertoire specifies the location of the point in cause-effect space, and the concept's formula_7 value specifies that point's magnitude.


title: Integrated information theory

text: In this way, a conceptual structure formula_8 can be plotted as a constellation of points in cause-effect space. Each point is called a star, and each star's magnitude (formula_7) is its size.


title: Integrated information theory

text: IIT addresses the mind-body problem by proposing an identity between phenomenological properties of experience and causal properties of physical systems: "The conceptual structure specified by a complex of elements in a state is identical to its experience."


title: Integrated information theory

text: Specifically, the form of the conceptual structure in cause-effect space completely specifies the quality of the experience, while the irreducibility formula_10 of the conceptual structure specifies the level to which it exists (i.e., the complex's level of consciousness). The maximally irreducible cause-effect repertoire of each concept within a conceptual structure specifies what the concept contributes to the quality of the experience, while its irreducibility formula_11 specifies how much the concept is present in the experience.


title: Integrated information theory

text: The calculation of even a modestly-sized system's formula_12 is often computationally intractable, so efforts have been made to develop heuristic or proxy measures of integrated information. For example, Masafumi Oizumi and colleagues have developed both formula_13 and geometric integrated information or formula_14, which are practical approximations for integrated information. These are related to proxy measures developed earlier by Anil Seth and Adam Barrett. However, none of these proxy measures have a mathematically proven relationship to the actual formula_12 value, which complicates the interpretation of analyses that use them. They can give qualitatively different results even for very small systems.


title: Integrated information theory

text: In 2021, Angus Leung and colleagues published a direct application of IIT's mathematical formalism to neural data. To circumvent the computational challenges associated with larger datasets, the authors focused on neuronal population activity in the fly. The study showed that formula_12 can readily be computed for smaller sets of neural data. Moreover, matching IIT's predictions, formula_12was significantly decreased when the animals underwent general anesthesia.


title: Integrated information theory

text: A significant computational challenge in calculating integrated information is finding the minimum information partition of a neural system, which requires iterating through all possible network partitions. To solve this problem, Daniel Toker and Friedrich T. Sommer have shown that the spectral decomposition of the correlation matrix of a system's dynamics is a quick and robust proxy for the minimum information partition.


title: Integrated information theory

text: While the algorithm for assessing a system's formula_12 and conceptual structure is relatively straightforward, its high time complexity makes it computationally intractable for many systems of interest. Heuristics and approximations can sometimes be used to provide ballpark estimates of a complex system's integrated information, but precise calculations are often impossible. These computational challenges, combined with the already difficult task of reliably and accurately assessing consciousness under experimental conditions, make testing many of the theory's predictions difficult.


title: Integrated information theory

text: Despite these challenges, researchers have attempted to use measures of information integration and differentiation to assess levels of consciousness in a variety of subjects. For instance, a recent study using a less computationally-intensive proxy for formula_12 was able to reliably discriminate between varying levels of consciousness in wakeful, sleeping (dreaming vs. non-dreaming), anesthetized, and comatose (vegetative vs. minimally-conscious vs. locked-in) individuals.


title: Integrated information theory

text: IIT also makes several predictions which fit well with existing experimental evidence, and can be used to explain some counterintuitive findings in consciousness research. For example, IIT can be used to explain why some brain regions, such as the cerebellum do not appear to contribute to consciousness, despite their size and/or functional importance.


title: Integrated information theory

text: Neuroscientist Christof Koch, who has helped to develop later versions of the theory, has called IIT "the only really promising fundamental theory of consciousness". Technologist and Koch's ex-student Virgil Griffith says "IIT is currently the leading theory of consciousness." However, his answer to whether IIT is exactly the right theory is ‘Probably not’.


title: Integrated information theory

text: Neuroscientist and consciousness researcher Anil Seth is supportive of the theory, with some caveats, claiming that "conscious experiences are highly informative and always integrated."; and that "One thing that immediately follows from [IIT] is that you have a nice post hoc explanation for certain things we know about consciousness.". But he also claims "the parts of IIT that I find less promising are where it claims that integrated information actually is consciousness — that there’s an identity between the two.", and has criticized the panpsychist extrapolations of the theory.


title: Integrated information theory

text: Philosopher David Chalmers, famous for the idea of the hard problem of consciousness, has expressed some enthusiasm about IIT. According to Chalmers, IIT is a development in the right direction, whether or not it is correct.


title: Integrated information theory

text: Philosopher Daniel Dennett considers IIT a theory of consciousness in terms of “integrated information that uses Shannon information theory in a novel way”. As such it has “a very limited role for "aboutness": it measures the amount of Shannon information a system or mechanism has about its own previous state—i.e., the states of all its parts”.


title: Integrated information theory

text: Physicist Max Tegmark has also expressed some support for the approach taken by IIT, and considers it compatible with his own ideas about consciousness as a "state of matter". Tegmark has also tried to address the problem of the computational complexity behind the calculations. According to Max Tegmark “the integration measure proposed by IIT is computationally infeasible to evaluate for large systems, growing super-exponentially with the system’s information content.” As a result, Φ can only be approximated in general. However, different ways of approximating Φ provide radically different results. Other works have shown that Φ can be computed in some large mean-field neural network models, although some assumptions of the theory have to be revised to capture phase transitions in these large systems.


title: Integrated information theory

text: One criticism made is that the claims of IIT as a theory of consciousness “are not scientifically established or testable at the moment”. However, while it is true that the complete analysis suggested by IIT cannot be completed at the moment for human brains, IIT has already been applied to models of visual cortex to explain why visual space feels the way it does.


title: Integrated information theory

text: Neuroscientists Björn Merker, David Rudrauf and Philosopher Kenneth Williford co-authored a paper criticizing IIT on several grounds. Firstly, by not demonstrating that all members of systems which do in fact combine integration and differentiation in the formal IIT sense are conscious, systems which demonstrate high levels of integration and differentiation of information might provide the necessary conditions for consciousness but those combinations of attributes do not amount to the conditions for consciousness. Secondly that the measure, Φ, reflects efficiency of global information transfer rather than level of consciousness, and that the correlation of Φ with level of consciousness through different states of wakefulness (e.g. awake, dreaming and dreamless sleep, anesthesia, seizures and coma) actually reflect the level of efficient network interactions performed for cortical engagement. Hence Φ reflects network efficiency rather than consciousness, which would be one of the functions served by cortical network efficiency. Of course, IIT emphasizes the importance of all five postulates being satisfied (not just information and integration) and does not claim that Φ is identical to consciousness, undermining the authors credibility on the topic of IIT and leaving their main criticism hamstrung.


title: Integrated information theory

text: Neuroscientist Michael Graziano, proponent of the competing attention schema theory, rejects IIT as pseudoscience. He claims IIT is a "magicalist theory" that has "no chance of scientific success or understanding".


title: Integrated information theory

text: Theoretical computer scientist Scott Aaronson has criticized IIT by demonstrating through its own formulation that an inactive series of logic gates, arranged in the correct way, would not only be conscious but be “unboundedly more conscious than humans are.” Tononi himself agrees with the assessment and argues that according to IIT, an even simpler arrangement of inactive logic gates, if large enough, would also be conscious. However he further argues that this is a strength of IIT rather than a weakness, because that's exactly the sort of cytoarchitecture followed by large portions of the cerebral cortex, specially at the back of the brain, which is the most likely neuroanatomical correlate of consciousness according to some reviews.


title: Integrated information theory

text: A peer-reviewed commentary by 58 scholars involved in the scientific study of consciousness rejects these conclusions about logic gates as “mysterious and unfalsifiable claims” that should be distinguished from “empirically productive hypotheses”. IIT as a scientific theory of consciousness has been criticized in the scientific literature as only able to be “either false or unscientific” by its own definitions. IIT has also been denounced by other members of the consciousness field as requiring “an unscientific leap of faith”, but it is not clear that this is in fact the case if the theory is properly understood. The theory has also been derided for failing to answer the basic questions required of a theory of consciousness. Philosopher Adam Pautz says “As long as proponents of IIT do not address these questions, they have not put a clear theory on the table that can be evaluated as true or false.”


title: Integrated information theory

text: Influential philosopher John Searle has given a critique of theory saying "The theory implies panpsychism" and "The problem with panpsychism is not that it is false; it does not get up to the level of being false. It is strictly speaking meaningless because no clear notion has been given to the claim.". However, whether or not a theory has panpsychist implications (that all or most of what exists physically must be, be part of something that is, or be composed of parts that are, conscious) has no bearing on the scientific validity of the theory. Searle's take has also been countered by other philosophers, for misunderstanding and misrepresenting a theory that is actually resonant with his own ideas.


title: Integrated information theory

text: The mathematics of IIT have also been criticized since “having a high Φ value requires highly specific structures that are unstable to minor perturbations”. This susceptibility to minor perturbations seems inconsistent with empirical results about neuroplasticity in the human brain, and thus weakening the theory. However, the systems investigated by Schwitzgebel were small networks of logic gates, and not human brains in normal waking conditions, and the generalizability to systems about which we have access to verified conscious experience (human beings) is questionable.


title: Integrated information theory

text: Philosopher Tim Bayne has criticized the axiomatic foundations of the theory. He concludes that “the so-called ‘axioms’ that Tononi et al. appeal to fail to qualify as genuine axioms”.


title: An Open Secret

text: An Open Secret is a 2014 American documentary film directed by Amy J. Berg exposing child sexual abuse in the film industry in California.


title: An Open Secret

text: Berg decided to make the documentary after she was approached by Matthew Valentinas in 2011. Valentinas and Gabe Hoffman wanted to make a film about victims of sexual exploitation. Valentinas said, "We chose Amy because we didn't want it to be exploitative or tabloid. We wanted it to be empowering for the victims." Matthew Valentinas, an entertainment lawyer, came up with the idea when he heard Corey Feldman talking about his sexual abuse as a child actor in a TV interview. Berg's 2006 film "Deliver Us from Evil", a documentary on systemic child sexual abuse in the Catholic Church, had been nominated for the Academy Award for Best Documentary Feature.


title: An Open Secret

text: The documentary follows the stories of five former child actors who were sexually abused by multiple predators. Much of the film focuses on Marc Collins-Rector, subsequently convicted of child sexual abuse, who co-owned and operated Digital Entertainment Network, with Brock Pierce also owning a minor share. DEN produced brief online videos during the early days of the Internet, and was noted for wild parties featuring underage boys at Collins-Rector's house.


title: An Open Secret

text: The film makes multiple references to director Bryan Singer, who was allegedly at some of the DEN parties, but does not detail allegations against him. A lawsuit alleging that Singer sexually abused Michael Egan as an underage boy was withdrawn during the production of the film. As a result, the film only details allegations made by persons willing to appear on camera.


title: An Open Secret

text: Among the people interviewed is "Vanity Fair" journalist John Connolly, who states that an article on pedophilia in Hollywood was dropped at the last minute by "Details" magazine.


title: An Open Secret

text: "An Open Secret" has an approval rating of 88% on Rotten Tomatoes, based on reviews from 17 critics. On Metacritic, the film has a weighted average score of 66 out of 100 based on reviews from nine critics, indicating "generally favorable reviews".


title: An Open Secret

text: "The Hollywood Reporter" wrote that the film offered a "sober look at accusations that lend themselves to sensationalism."


title: An Open Secret

text: "The Los Angeles Times" describes the movie as "not the hard-hitting exposé that it aims to be" but as "an unsettling look at pedophilia in Hollywood".


title: An Open Secret

text: "The New York Times" wrote that the "topic deserves a tenacious call for answers" and hoped for "further aggressive reporting" which they missed in the movie, when Berg linked Martin Weiss "to a string of other men" but only presenting "a secretly taped conversation and some menacing music".


title: An Open Secret

text: "Flavorwire" claims that "the film feels less shocking as a cult-of-celebrity document and more just quietly horrifying, as it details the trauma and the abuse of power inflicted on young men with stars in their eyes."


title: An Open Secret

text: "Indiewire" described the documentary as "an incisive and utterly unflinching look at a subject too rarely scrutinized."


title: An Open Secret

text: On July 30, 2015, "Deadline Hollywood" reported that the producers of "An Open Secret" accused Berg of not supporting the film. Producers Gabe Hoffman and Matthew Valentinas filed an arbitration against Berg for allegedly delivering the movie late and incomplete, and failing to promote it. Hoffman's Esponda Productions claimed that Berg failed to get the proper release forms from some of the interviewees and that this error almost caused the film to miss its premiere at Doc NYC.


title: An Open Secret

text: Another controversy arose when the "Huffington Post" reported that two of the movie's subjects, Evan Henzi and Chris Turcotte, had called the documentary "unfair" and "dishonest". In another "Huffington Post" article, Turcotte said that Berg omitted portions of his interview from the movie, detailing that Collins-Rector had sex at the estate with underage teens in private, but not during sex parties.


title: An Open Secret

text: These controversies appear to be substantiated in Michael Egan's sexual abuse claims against Bryan Singer and three others. "His cases against the four men began to collapse in May 2014, just a month after they were filed, when his prior contradictory statements came to light". Egan's attorneys, Jeff Herman and Mark Gallagher, later settled with Garth Ancier and David Neuman and issued an apology that called the allegations "untrue" and paid a seven-figure settlement to both. Neither Singer nor Gary Goddard received an apology because they didn't file countersuits as Ancier and Neuman had, although "Egan’s cases against all four were framed in virtually identical complaints and centered on the same purported events, timeframes, locations and supposed trip(s) to Hawaii".


title: An Open Secret

text: The documentary previously named all four men in connection with the 2014 lawsuits, but was edited to remove those references.


title: An Open Secret

text: "An Open Secret" initially had a limited theatrical release, but producers were encouraged about its commercial potential because a pirated version was viewed 900,000 times. However, it received no television deal or video-on-demand distribution. According to Gabe Hoffman, who financed the film: "We got zero Hollywood offers to distribute the film. Not even one. Literally no offers for any price whatsoever." On October 12, 2017, Hoffman and Valentinas released the film for nine days on Vimeo "to commemorate serial predator Harvey Weinstein finally being exposed." It went viral, and free viewing was then extended for a longer period due to the interest shown in the film, with over 3 million viewings garnered on various social media platforms in the first two weeks.


title: An Open Secret

text: At the time of its Vimeo release, the producers said they were seeking further distribution of the documentary. It has not been released to home video.


title: Nicolas Léonard Sadi Carnot

text: "Sous-lieutenant" Nicolas Léonard Sadi Carnot (; 1 June 1796 – 24 August 1832) was a French mechanical engineer in the French Army, military scientist and physicist, and often described as the "father of thermodynamics". He published only one book, the "Reflections on the Motive Power of Fire" (Paris, 1824), in which he expressed the first successful theory of the maximum efficiency of heat engines and laid the foundations of the new discipline: thermodynamics. Carnot's work attracted little attention during his lifetime, but it was later used by Rudolf Clausius and Lord Kelvin to formalize the second law of thermodynamics and define the concept of entropy. Based on purely technical concerns, such as improving the performance of the steam engine, Sadi Carnot's intellect laid the groundwork for modern science technological designs, such as the automobile or jet engine.


title: Nicolas Léonard Sadi Carnot

text: His father Lazare Carnot was an eminent mathematician, military engineer, and leader of the French Revolutionary Army.


title: Nicolas Léonard Sadi Carnot

text: Nicolas Léonard Sadi Carnot was born in Paris at the Palais du Petit-Luxembourg into a family that was distinguished in both science and politics. He was the first son of Lazare Carnot, who chose his son's third given name Sadi (by which he would always be known) after the Persian poet Sadi of Shiraz. Sadi was the elder brother of statesman Hippolyte Carnot and the uncle of Marie François Sadi Carnot, who would serve as President of France from 1887 to 1894.


title: Nicolas Léonard Sadi Carnot

text: His father Lazare Carnot knowing his son's potential, sent him to Lycée Charlemagne in Paris to prepare him for the examinations to École polytechnique. In 1811, at the age of 16, the minimum age possible, Sadi Carnot became a cadet in the École Polytechnique in Paris, where his classmates included Michel Chasles and Gaspard-Gustave Coriolis. The École Polytechnique was intended to train engineers for military service, but its professors included such eminent scientists as André-Marie Ampère, François Arago, Joseph Louis Gay-Lussac, Louis Jacques Thénard, Jean Nicolas Pierre Hachette, Jean-Henri Hassenfratz, Antoine André Louis Reynaud, and Siméon Denis Poisson. Thus, the school had become renowned for its mathematical instruction.


title: Nicolas Léonard Sadi Carnot

text: After graduating in 1814, Sadi went to study in École du Génie at Metz to study the two year course in military engineering. Sadi then became an officer in the French army's corps of engineers. His father Lazare had served as Napoleon's minister of the interior during the "Hundred Days", and, after Napoleon's final defeat in 1815, Lazare was forced into exile. Sadi's position in the army, under the restored Bourbon monarchy of Louis XVIII, became increasingly difficult.


title: Nicolas Léonard Sadi Carnot

text: Sadi Carnot was posted to different locations, where he inspected fortifications, tracked plans, and wrote many reports. It appeared that his recommendations were ignored and his career was stagnating. On 15 September 1818 he took a six-month leave to prepare for the entrance examination of Royal Corps of Staff and School of Application for the Service of the General Staff.


title: Nicolas Léonard Sadi Carnot

text: In 1819, Sadi transferred to the newly formed General Staff in Paris. He remained on call for military duty, but from then on he dedicated most of his attention to private intellectual pursuits and received only two-thirds pay. Carnot befriended Nicolas Clément and Charles-Bernard Desormes and attended lectures on physics and chemistry. He became interested in understanding the limitation to improving the performance of steam engines, which led him to the investigations that became his "Reflections on the Motive Power of Fire", published in 1824.


title: Nicolas Léonard Sadi Carnot

text: Carnot retired from the army in 1828, without a pension. He was interned in a private asylum in 1832 as suffering from "mania" and "general delirum", and he died of cholera shortly thereafter, aged 36, at the hospital in Ivry-sur-Seine.


title: Nicolas Léonard Sadi Carnot

text: When Carnot began working on his book, steam engines had achieved widely recognized economic and industrial importance, but there had been no real scientific study of them. Newcomen had invented the first piston-operated steam engine over a century before, in 1712; some 50 years after that, James Watt made his celebrated improvements, which were responsible for greatly increasing the efficiency and practicality of steam engines. Compound engines (engines with more than one stage of expansion) had already been invented, and there was even a crude form of internal-combustion engine, with which Carnot was familiar and which he described in some detail in his book. Although there existed some intuitive understanding of the workings of engines, scientific theory for their operation was almost nonexistent. In 1824 the principle of conservation of energy was still poorly developed and controversial, and an exact formulation of the first law of thermodynamics was still more than a decade away; the mechanical equivalence of heat would not be formulated for another two decades. The prevalent theory of heat was the caloric theory, which regarded heat as a sort of weightless and invisible fluid that flowed when out of equilibrium.


title: Nicolas Léonard Sadi Carnot

text: Engineers in Carnot's time had tried, by means such as highly pressurized steam and the use of fluids, to improve the efficiency of engines. In these early stages of engine development, the efficiency of a typical engine—the useful work it was able to do when a given quantity of fuel was burned—was only 3%.


title: Nicolas Léonard Sadi Carnot

text: Carnot wanted to answer two questions about the operation of heat engines: "Is the work available from a heat source potentially unbounded?" and "Can heat engines in principle be improved by replacing the steam with some other working fluid or gas?" He attempted to answer these in a memoir, published as a popular work in 1824 when he was only 27 years old. It was entitled "Réflexions sur la Puissance Motrice du Feu" ("Reflections on the Motive Power of Fire"). The book was plainly intended to cover a rather wide range of topics about heat engines in a rather popular fashion; equations were kept to a minimum and called for little more than simple algebra and arithmetic, except occasionally in the footnotes, where he indulged in a few arguments involving some calculus. He discussed the relative merits of air and steam as working fluids, the merits of various aspects of steam engine design, and even included some ideas of his own regarding possible practical improvements. The most important part of the book was devoted to an abstract presentation of an idealized engine that could be used to understand and clarify the fundamental principles that are generally applied to all heat engines, independent of their design.


title: Nicolas Léonard Sadi Carnot

text: Perhaps the most important contribution Carnot made to thermodynamics was his abstraction of the essential features of the steam engine, as they were known in his day, into a more general and idealized heat engine. This resulted in a model thermodynamic system upon which exact calculations could be made, and avoided the complications introduced by many of the crude features of the contemporary steam engine. By idealizing the engine, he could arrive at clear and indisputable answers to his original two questions.


title: Nicolas Léonard Sadi Carnot

text: He showed that the efficiency of this idealized engine is a function only of the two temperatures of the reservoirs between which it operates. He did not, however, give the exact form of the function, which was later shown to be (T−T)/T, where T is the absolute temperature of the hotter reservoir. (Note: This equation probably came from Kelvin.) No thermal engine operating any other cycle can be more efficient, given the same operating temperatures.


title: Nicolas Léonard Sadi Carnot

text: The Carnot cycle is the most efficient possible engine, not only because of the (trivial) absence of friction and other incidental wasteful processes; the main reason is that it assumes no conduction of heat between parts of the engine at different temperatures. Carnot knew that the conduction of heat between bodies at different temperatures is a wasteful and irreversible process, which must be eliminated if the heat engine is to achieve maximum efficiency.


title: Nicolas Léonard Sadi Carnot

text: Regarding the second point, he also was quite certain that the maximum efficiency attainable did not depend upon the exact nature of the working fluid. He stated this for emphasis as a general proposition:


title: Nicolas Léonard Sadi Carnot

text: For his "motive power of heat", we would today say "the efficiency of a reversible heat engine", and rather than "transfer of caloric" we would say "the reversible transfer of entropy ∆S" or "the reversible transfer of heat at a given temperature Q/T". He knew intuitively that his engine would have the maximum efficiency, but was unable to state what that efficiency would be.


title: Nicolas Léonard Sadi Carnot

text: In an idealized model, the caloric transported from a hot to a cold body by a frictionless heat engine that lacks of conductive heat flow, driven by a difference of temperature, yielding work, could also be used to transport the caloric back to the hot body by reversing the motion of the engine consuming the same amount of work, a concept subsequently known as thermodynamic reversibility. Carnot further postulated that no caloric is lost during the operation of his idealized engine. The process being completely reversible, executed by this kind of heat engine is the most efficient possible process. The assumption that heat conduction driven by a temperature difference cannot exist, so that no caloric is lost by the engine, guided him to design the Carnot-cycle to be operated by his idealized engine. The cycle is consequently composed of adiabatic processes where no heat/caloric ∆S = 0 flows and isothermal processes where heat is transferred ∆S > 0 but no temperature difference ∆T = 0 exist. The proof of the existence of a maximum efficiency for heat engines is as follows:


title: Nicolas Léonard Sadi Carnot

text: As the cycle named after him doesn't waste caloric, the reversible engine has to use this cycle. Imagine now two large bodies, a hot and a cold one. He postulates now the existence of a heat machine with a greater efficiency. We couple now two idealized machine but of different efficiencies and connect them to the same hot and the same cold body. The first and less efficient one lets a constant amount of entropy ∆S = Q/T flow from hot to cold during each cycle, yielding an amount of work denoted W. If we use now this work to power the other more efficient machine, it would, using the amount of work W gained during each cycle by the first machine, make an amount of entropy ∆S' > ∆S flow from the cold to the hot body. The net effect is a flow of ∆S' − ∆S ≠ 0 of entropy from the cold to the hot body, while no net work is done. Consequently, the cold body is cooled down and the hot body rises in temperature. As the difference of temperature rises now the yielding of work by the first is greater in the successive cycles and due to the second engine difference in temperature of the two bodies stretches by each cycle even more. In the end this set of machines would be a perpetuum mobile that cannot exist. This proves that the assumption of the existence of a more efficient engine was wrong so that a heat engine that operates the Carnot cycle must be the most efficient one. This means that a frictionless heat engine that lacks of conductive heat flow driven by a difference of temperature shows maximum possible efficiency.


title: Nicolas Léonard Sadi Carnot

text: He concludes further that the choice of the working fluid, its density or the volume occupied by it cannot change this maximum efficiency. Using the equivalence of any working gas used in heat engines he deduced that the difference in the specific heat of a gas measured at constant pressure and at constant volume must be constant for all gases.


title: Nicolas Léonard Sadi Carnot

text: By comparing the operation of his hypothetical heat engines for two different volumes occupied by the same amount of working gas he correctly deduces the relation between entropy and volume for an isothermal process:


title: Nicolas Léonard Sadi Carnot

text: Carnot's book received very little attention from his contemporaries. The only reference to it within a few years after its publication was in a review in the periodical "Revue Encyclopédique", which was a journal that covered a wide range of topics in literature. The impact of the work had only become apparent once it was modernized by Émile Clapeyron in 1834 and then further elaborated upon by Clausius and Kelvin, who together derived from it the concept of entropy and the second law of thermodynamics. Rankine, who introduced the term "potential energy" in 1853, was later made aware that an equivalent phrase, "in its purely mechanical sense, had been anticipated by Carnot", who had employed the term "force vive virtuelle".


title: Nicolas Léonard Sadi Carnot

text: On Carnot's religious views, he was a Philosophical theist. He believed in divine causality, stating that "what to an ignorant man is chance, cannot be chance to one better instructed," but he did not believe in divine punishment. He criticized established religion, though at the same time spoke in favor of "the belief in an all-powerful Being, who loves us and watches over us."


title: Nicolas Léonard Sadi Carnot

text: Because of the contagious nature of cholera, many of Carnot's belongings and writings were buried together with him after his death. As a consequence, only a handful of his scientific writings survived.


title: Nicolas Léonard Sadi Carnot

text: After the publication of "Reflections on the Motive Power of Fire", the book quickly went out of print and for some time was very difficult to obtain. Kelvin, for one, had a difficult time getting a copy of Carnot's book. In 1890 an English translation of the book was published by R. H. Thurston; this version has been reprinted in recent decades by Dover and by Peter Smith, most recently by Dover in 2005. Some of Carnot's posthumous manuscripts have also been translated into English.


title: Nicolas Léonard Sadi Carnot

text: Carnot published his book in the heyday of steam engines. His theory explained why steam engines using superheated steam were better because of the higher temperature of the consequent hot reservoir. Carnot's theories and efforts did not immediately help improve the efficiency of steam engines; his theories only helped to explain why one existing practice was superior to others. It was only towards the end of the nineteenth century that Carnot's ideas, namely that a heat engine can be made more efficient if the temperature of its hot reservoir is increased, were put into practice. Carnot's book did, however, eventually have a real impact on the design of practical engines. Rudolf Diesel, for example, used Carnot's theories to design the diesel engine, in which the temperature of the hot reservoir is much higher than that of a steam engine, resulting in an engine which is more efficient.


title: Red McCombs

text: Billy Joe "Red" McCombs (born October 19, 1927) is an American businessman. He is the founder of the Red McCombs Automotive Group in San Antonio, Texas, a co-founder of Clear Channel Communications, former chairman of Constellis Group, a former owner of the San Antonio Spurs, San Antonio Force, Denver Nuggets, the Minnesota Vikings, and the namesake of the McCombs School of Business at the University of Texas at Austin. He is on the Forbes 400 list of richest Americans.


title: Red McCombs

text: In 2012, the "San Antonio Express-News" reported McCombs' net worth at $1.4 billion. He was ranked the 913th richest man in the world. Two other San Antonio men at the time, Charles Butt of the H-E-B supermarket chain and Rodney Lewis, a natural gas driller, finished above McCombs on the list. In 2017, "Forbes" placed the value of McCombs' fortune at $1.6 billion with a ranking of No. 1,290 on a list of the world's billionaires.


title: Red McCombs

text: McCombs was born in rural Spur in Dickens County in West Texas. His nickname "Red" comes from his hair color. His father was a mechanic who earned $25 per week but tithed through the First Baptist Church of Spur each week. McCombs recalled having seen his parents "share with those who had less, and the joy of giving never ceased to amaze me."


title: Red McCombs

text: In 1958, McCombs and his fellow salesman, Austin Hemphill, moved to San Antonio to create Hemphill-McCombs Ford, which was the foundation for what ultimately became the Red McCombs Automotive Group. McCombs has served as chairman of the trustees at Southwestern University and chairman of the University of Texas's M. D. Anderson Cancer Center in Houston. His particular interest in M. D. Anderson was accentuated in 1986, when he visited a dying friend undergoing treatment there. He expressed how he was overcome by the kindness of every employee he met at the hospital. The workers, he found, had been trained to offer compassion and solace to all who come through the doors. He joined the Anderson board and in 2005 donated $30 million to the hospital. The business school at the University of Texas was renamed the Red McCombs School of Business in recognition of his $50 million donation to the institution. The $50 million actually yielded $100 million in matching funds for new faculty positions, fellowships, and scholarships.


title: Red McCombs

text: He is the board chairman of Academi. McCombs is a member of the Alamo Endowment Board, which raises funds for the preservation and management of the Alamo Mission in downtown San Antonio. With the state purchasing three historic buildings in Alamo Plaza, McCombs said in October 2015 that he envisions an expansion program consistent with the reality of the Alamo story to enhance the overall experience of future visitors to the historic site.


title: Red McCombs

text: McCombs is a reformed alcoholic, who could "handle his social drinking" until the age of 48, when overcome with convulsions he went into a five-day coma at a medical facility in Houston. McCombs said in a Christmas 2016 interview, "God was good to me and for whatever reason wanted me to live, because I was really dead when I left in 1975 to go to Houston on that medical plane. They told Charline, 'Go ahead and start making arrangements because we are losing him.'" McCombs said that he recovered and never again had a desire for alcohol. The McCombs Foundation has donated more than $118 million to charity. It is operated by his daughters who work to keep overhead at a minimum. The foundation makes small donations too, such as $1,000 to Mothers Against Drunk Driving, which are rarely publicized. McCombs said that he is a large donor to charitable causes because "it makes me feel so good about doing it."


title: Red McCombs

text: In 2017, McCombs filed a $1 million civil suit against seven of his former executives whom he alleged took "trade secrets" from McCombs' company to begin a competing firm in Houston, F4 Resources. Defendants in the suit include William "Bill" Forney, Jr., who worked with McCombs for forty-four years, former chief financial officer Ricky Halkin, vice president of operations Larry Wyont, vice president of land Charles Forney, and the vice president of geology, Philip Forney. McCombs had established McCombs Energy in Houston in 1998 by merging his 50 percent interest in his partnership with William Forney with other assets purchased from Forney. McCombs claims that his former associates, however, lowered the proper payout that he was due from his investments. McCombs said that the former executives shattered personal relationships of some four decades.


title: Red McCombs

text: McCombs attributes construction of the HemisFair Arena as the essential development to the success of the Spurs. He contacted Lee Iacocca, then president of the Ford Motor Company, to seek funding for the arena to correspond with the 1968 World's Fair. At first, Iacocca offered only $250,000 for the purchase of an art object, and he scolded McCombs and ridiculed San Antonio as "that little old dusty ass town of yours down there [with] no political or economic significance to the Ford Motor Company." McCombs persisted and asked U.S. President Lyndon B. Johnson to contact Henry Ford, II, and in a continued heated exchange even told Iacocca that Ford needed to improve the quality of its 1968 vehicles. McCombs located other investors, and the Dallas Chaparrals came to San Antonio five years later in 1973. McCombs realized the importance of television to sports events and saw the opportunity to bring San Antonio to a national stage. Under the McCombs administration the Spurs had their first superstar in George Gervin, called "The Iceman", who was recruited from the Virginia Squires.


title: Red McCombs

text: Two years after taking the Spurs into the NBA, McCombs sold off his stake in the Spurs and bought another former ABA team, the Denver Nuggets. He held onto the team until 1985, when he sold it to Sidney Shlenker. In 1998, McCombs bought the Minnesota Vikings for US$250 million. After an unsuccessful attempt to replace the Hubert H. Humphrey Metrodome, McCombs sold the team to new (and current) owner Zygi Wilf before the 2005 NFL season. McCombs was also actively involved in thoroughbred racing and breeding for many years as a major partner in Walmac Farm, a leading American breeding farm, in Lexington, Kentucky.


title: Red McCombs

text: McCombs was one of the first investors of the Circuit of the Americas. In December 2020 he got his 'own' corner called 'Big Red'.


title: Red McCombs

text: McCombs owns a piece of property surrounded by National Forest near Wolf Creek ski area, a resort in southern Colorado owned by the Pitcher family. McCombs has long wanted to develop a resort community on his property, a plan that has drawn opposition and lawsuits from environmentalists and surrounding communities. McCombs has been unsuccessful in his attempts to convince the court to remove a key roadblock preventing his proposed development. McCombs then attempted to build a casino resort at Navajo Canyon on Lake Powell. The local Navajo Nation chapters, local government officials, all unanimously rejected the casino proposal and any projects by Red McCombs.


title: Red McCombs

text: In 2013, McCombs was found by the United States Supreme Court to have engaged in a sham tax avoidance transaction and was therefore liable for a valuation misstatement penalty. Additionally, McCombs severely criticized the 2014 University of Texas hire of Charlie Strong as football coach. He described Strong as "great position coach ... not on a par with other candidates." Three days later he apologized, and pledged "total support" for Strong.


title: Eurocopter EC155

text: The Eurocopter EC155 (now Airbus Helicopters H155) is a long-range medium-lift passenger transport helicopter developed by Eurocopter from its Dauphin family for civil aviation use. It is a twin-engined aircraft and can carry up to 13 passengers along with 1 or 2 crew, depending on customer configuration. The helicopter is marketed for passenger transport, offshore support, VIP corporate transport and casualty transport duties. In 2015, the EC155 was formally renamed to the H155, in line with Eurocopter's corporate rebranding as Airbus Helicopters.


title: Eurocopter EC155

text: Originally designated AS365 N4, the EC155 was developed from the Eurocopter AS365 N3 Dauphin 2 with the aim of significantly increasing the cabin space of the Dauphin. Development began in September 1996 with the helicopter officially announced by Eurocopter at the Paris Air Show in June 1997. The first EC155 helicopter, a modified Dauphin airframe, made its maiden flight at Marignane on 17 June 1997 and the first pre-production EC155 B flew on 11 March 1998. The aircraft received safety certification by the French and German civil aviation authorities on 11 December 1998 and went into production soon after, with a price tag of US$7–8 million depending on installed equipment.


title: Eurocopter EC155

text: In March 1999, deliveries of the EC155 B commenced, the German Federal Police became the first operator of the type. Between March 1999 and June 2003, roughly 50 EC155 Dauphins were sold, mainly to VIP and off-shore customers.


title: Eurocopter EC155

text: The EC155 B1 was developed with uprated engines, giving it improved performance at high altitude and in hot temperature conditions; this derivative also features a higher maximum take-off weight (10,846 lb vs. 10,580 lb). Deliveries of this model began in November 2002 with the Hong Kong Government Flying Service becoming the first operator. In early 2003, Eurocopter completed studies for an even more powerful version of the EC155 B1, designed to better compete with new rotorcraft such as the AgustaWestland AW139 and to better meet military customer's requirements.


title: Eurocopter EC155

text: Several major elements of the EC155, such its rotor system (albeit modified to operate at slower rotational speeds), were used in the Eurocopter X3, an experimental high-speed compound helicopter which set an unofficial speed record of in 2013. In 2015, an EC155 was also used by Airbus Helicopters as a flying testbed for new aerodynamic features, such as the rotor blades, biplane stabilizer and canted fenestron, for the developing Airbus Helicopters H160 helicopter.


title: Eurocopter EC155

text: In 2015, Airbus Helicopters and Korean Aerospace Industries (KAI) formed an agreement to transfer principle manufacturing activity for the EC155 to South Korea; KAI shall become the sole manufacturer of the type after 2018, and both firms shall be jointly involved in the international marketing and further development of the type. The EC155 is to serve as the basis for KAI's Light Civil Helicopter (LCH) and Light Armed Helicopter (LAH), featuring numerous changes including a new cockpit, improved gearbox and rotor blades; the LAH shall have a chin-mounted 20 mm cannon and side-mounted guided rockets, countermeasures systems, and be able to carry 6–10 combat troops. The LCH is to enter service in 2020, and the LAH will follow in 2022 to replace the MD 500 Defender and AH-1J/S Cobra. Airbus foresees a South Korean demand for 100 LCHs and 214 LAHs, and estimates an international market of 300–400 LAH versions to replace legacy attack helicopters.


title: Eurocopter EC155

text: The EC155 B features a completely redesigned cabin providing 30% more passenger space than previous Dauphin helicopter models, plus a 130% increase in baggage hold volume. Other major improvements include a five-blade Spheriflex composite main rotor combined with the familiar shrouded Fenestron tail rotor to reduce vibration levels significantly. The EC155 B is powered by two 635 kW (851 shp) Turbomeca Arriel 2C1 turboshaft engines mounted over the luggage hold, which feature a dual-channel Full Authority Digital Engine Control (FADEC) system. The EC155 B1 features uprated 697 kW (935 shp) Arriel 2C2s. The helicopter can be fitted with an anti-icing system to enable the aircraft to operate in very cold climates. The all-glass cockpit is equipped with an 'Avionique Nouvelle' integrated digital flight control system featuring Eurocopter's Vehicle and Engine Management Display (VEMD), which utilizes active matrix liquid crystal displays. The EC155 is also equipped with a four-axis digital autopilot, coupled to the engine FADECs for full-envelope protection, and is offered with a Health and Usage Monitoring System (HUMS).


title: Eurocopter EC155

text: Eurocopter designed the EC155 originally with three configurations, however, another two configurations were added in 2005. The Passenger Transport version can carry 12 passengers in comfort seats or 13 passengers in utility seats, along with 1 or 2 crew. The VIP or Corporate Transport version has a VIP lounge with working space accommodating up to 8 executives. The Casualty Transport version can carry 2 stretchered patients with up to 4 seated medical staff, or 4 patients on stretchers plus 2 seated medical staff. The configurations added in 2005 were for offshore operation and police and parapublic missions ranging from patrol, airborne surveillance, SAR and EMS, the helicopter being fitted with specific mission equipment for these duties.


title: Eurocopter EC155

text: The aircraft is operated by private individuals, companies and charter operators. It is also operated by government organisations and as an offshore transport for the gas and oil industry.


title: Dorking

text: Dorking () is a market town in Surrey in South East England, about south of London. It is in Mole Valley District and the council headquarters are to the east of the centre. The High Street runs roughly east–west, parallel to the Pipp Brook and along the northern face of an outcrop of Lower Greensand. The town is surrounded on three sides by the Surrey Hills Area of Outstanding Natural Beauty and is close to Box Hill and Leith Hill.


title: Dorking

text: The earliest archaeological evidence of human activity is from the Mesolithic and Neolithic periods, and there are several Bronze Age bowl barrows in the local area. The town may have been the site of a staging post on Stane Street during Roman times, however the name 'Dorking' suggests an Anglo-Saxon origin for the modern settlement. A market is thought to have been held at least weekly since early medieval times and was highly regarded for the poultry traded there. The Dorking breed of domestic chicken is named after the town.


title: Dorking

text: The local economy thrived during Tudor times, but declined in the 17th century due to poor infrastructure and competition from neighbouring towns. During the early modern period many inhabitants were nonconformists, including the author, Daniel Defoe, who lived in Dorking as a child. Six of the "Mayflower" Pilgrims, including William Mullins and his daughter Priscilla, lived in the town before setting sail for the New World.


title: Dorking

text: Dorking started to expand during the 18th and 19th centuries as transport links improved and farmland to the south of the centre was released for housebuilding. The new turnpike, and later the railways, facilitated the sale of lime produced in the town, but also attracted wealthier residents, who had had no previous connection to the area. Residential expansion continued in the first half of the 20th century, as the Deepdene and Denbies estates began to be broken up. Further development is now constrained by the Metropolitan Green Belt, which encircles the town.


title: Dorking

text: The origins and meaning of the name Dorking are uncertain. Early spellings include "Dorchinges" (1086), "Doreking" (1138–47), "Dorkinges" (1180), and "Dorkingg" (1219). Both principal elements in the name are disputed. The first element may be from a personal name, "Deorc", or some variant, of either Brittonic or Old English origin. Alternatively it may derive from the Brittonic words "Dorce", a river name meaning "clear, bright stream", or "duro", meaning a "fort", "walled town" or "gated place". The second element, if originally plural ("ingas"), might mean "(settlement belonging to the) followers of ...", but if singular ("ing") might mean "place", "stream", "wood" or "clump".


title: Dorking

text: Dorking is in central Surrey, about south of London and east of Guildford. It is close to the intersection of two valleys – the north-south Mole Gap (where the River Mole cuts through the North Downs) and the west–east Vale of Holmesdale (a narrow strip of low-lying land between the North Downs and the Greensand Ridge). The highest point in the town is the Glory Wood, south east of the centre, where the summit () is marked by a Bronze Age bowl barrow.


title: Dorking

text: The basic plan of the town centre has not changed since medieval times (and may be Anglo-Saxon in origin). The main streets (the High Street, West Street and South Street) meet at Pump Corner, forming a " Y " shape. Together, West Street and the High Street run approximately west–east, paralleling the Pipp Brook, a tributary of the Mole, which runs to the north of the centre.


title: Dorking

text: The town is surrounded by the Metropolitan Green Belt (which also covers the Glory Wood) and is bordered on three sides by the Surrey Hills Area of Outstanding Natural Beauty. Several Sites of Special Scientific Interest are close by, including the Mole Gap to Reigate Escarpment, immediately to the north. The National Trust owns several properties in the area, including Box Hill, Leith Hill Tower and Polesden Lacey.


title: Dorking

text: The rock strata on which Dorking sits, belong primarily to the Lower Greensand Group. This group is multilayered and includes the sandy Hythe Beds, the clayey Sandgate Beds and the quartz-rich Folkestone Beds. The lower greensand was deposited in the early Cretaceous, most likely in a shallow sea with low oxygen levels. Over the subsequent 50 million years, other strata were deposited on top of the Lower Greensand, including Gault clay, Upper Greensand and the chalk of the North and South Downs.


title: Dorking

text: Following the Cretaceous, the sea covering the south of England began to retreat and the land was pushed higher. The Weald (the area covering modern-day south Surrey, south Kent, north Sussex and east Hampshire) was lifted by the same geological processes that created the Alps, resulting in an anticline which stretched across the English Channel to the Artois region of northern France. Initially an island, this dome-like structure was drained by the ancestors of the rivers which today cut through the North and South Downs, including the Mole. The dome was eroded away over the course of the Cenozoic, exposing the strata beneath and resulting in the escarpments of the Downs and the Greensand Ridge.


title: Dorking

text: In Dorking, the dividing line between the Lower Greensand and Gault clay is marked by the course of the Pipp Brook. In the south of the town, the Hythe Beds take the form of iron-rich, soft, fine-grained sandstone, whereas the Sandgate Beds have a more loamy composition. The quartz-rich Folkestone Beds have a lower iron content, and contain veins of silver sand and rose-coloured ferruginous sand. Running along the north bank of the Pipp Brook (with a width of around ) is the outcrop of Gault, a blue-black shaly clay, beyond which is a narrow band of Upper Greensand, a hard, grey mica-rich sandstone. In the extreme north west of the town, the marly Lower Chalk was quarried for lime production until the early 20th century.


title: Dorking

text: Ammonite fossils are found in the north of the town, including "Stoliczkia", "Callihoplites", "Acanthoceras" and "Euomphaloceras" species in the Lower Chalk and "Puzosia" species in the Upper Greensand. Foraminifera fossils have been found in the Hythe Beds adjacent to the Horsham road, to the west of Tower Hill.


title: Dorking

text: The earliest evidence of human activity in Dorking comes from the Mesolithic and Neolithic periods and includes flint tools and flakes found during construction development in South Street. A ring ditch containing two ceramic urns, was discovered in 2013 during the rebuilding of Waitrose supermarket. Radiocarbon dating of hazelnut shells found at the base suggests that it was dug between 8625 and 8465 BCE and may have enclosed a bowl barrow. Other ditches nearby may indicate the presence of a Bronze Age field system, although the date of these later earthworks is less certain. Bowl barrows from the same period have been found at the Glory Wood (to the south of the town centre), on Milton Heath (to the west) and on Box Hill (to the northeast).


title: Dorking

text: There is thought to have been a settlement at Dorking in Roman times, although its size and extent are unclear. Coins from the reigns of Hadrian (117–138 AD), Commodus (180–192) and Claudius Gothicus (214–270), as well as tiles and pottery fragments, have been found in the town. Stane Street, the Roman road linking London to Chichester, was constructed during the first century AD and is thought to have run through Dorking. The exact course through the town is not known and no definitive archaeological evidence has been discovered for the route in the gap between the crossing of the River Mole at the Burford Bridge and North Holmwood. A posting station is thought to have been located in the area and sites have been proposed in the town centre, at Pixham and at the Burford Bridge, where the road crossed the River Mole.


title: Dorking

text: Although the name Dorking implies a settlement that was well established by the time of the Norman conquest, archaeological evidence of Saxon activity in the town centre is limited to pottery sherds. Probable Saxon cemeteries have been found close to Yew Tree Road (to the north of the centre) and at Vincent Lane (to the west). In 1817, the so-called "Dorking Hoard" of around 700 silver pennies, dating from the mid-8th to the late-9th centuries, was found near the source of the Pipp Brook on the northern slopes of Leith Hill. In the late Saxon period, the manor and parish were administered as part of the Wotton Hundred and may have been part of a large royal estate centred on Leatherhead.


title: Dorking

text: Dorking appears in Domesday Book of 1086 as the Manor of "Dorchinges". It was held by William the Conqueror, who had assumed the lordship in 1075 on the death of Edith of Wessex, widow of Edward the Confessor. The settlement included one church, three mills worth 15s 4d, 16 ploughs, woodland and herbage for 88 hogs and of meadow. It rendered £18 per year in 1086. The residents included 38 villagers, 14 smallholders and 4 villeins, which placed it in the top 20% of settlements in England by population.


title: Dorking

text: In around 1087, William II granted the manor of Dorking to Willam de Warenne, the first Earl of Surrey, whose descendants have held the lordship almost continuously until the present day. By the early 14th century, the manor had been divided for administrative purposes into four tithings: Eastburgh and Chippingburgh (corresponding respectively to the eastern and western halves of the modern town); Foreignburgh (the area covered by the Holmwoods) and Waldburgh (which would later be renamed Capel). On the death of the seventh Earl, John de Warenne, in 1347, the manor passed to his brother-in-law, Richard Fitzalan, the third Earl of Arundel. In 1580 both Earldoms passed through the female line to Phillip Howard, whose father, Thomas Howard, had forfeited the title of Duke of Norfolk and had been executed for his involvement in the Ridolfi plot to assassinate Elizabeth I. The dukedom was restored to the family in 1660, following the accession of Charles II.


title: Dorking

text: As the status of the de Warennes and their descendants increased, they became less interested in the town. In the 14th and 15th centuries, prominent local families (including the Sondes and the Goodwyns) were able to buy the leases on some of the lordship lands. One such area was the Deepdene, first mentioned in a court roll of 1399. This woodland was held by several tenants, before being inherited in 1652 by Charles Howard, the fourth son of the 15th Earl of Arundel, in whose family it remained until 1790. The estate was expanded by successive owners, including the Anglo-Dutch banker Thomas Hope and his eldest son Henry Thomas Hope, who commissioned William Atkinson to remodel the main house as a "sumptuous High Renaissance palazzo".


title: Dorking

text: Unlike the neighbouring towns of Guildford and Reigate, Dorking was never granted a Borough Charter and remained under the control of the Lord of the Manor throughout the Middle Ages. Reforms during the Tudor period reduced the importance of manorial courts and the day-to-day administration of towns such as Dorking became the responsibility of the vestry of the parish church. There was little change in local government structure over the subsequent three centuries, until the Poor Law Amendment Act 1834 transferred responsibility for poor relief to the Poor Law Commission, whose local powers were delegated to the newly formed poor law union in 1836. In 1841, the Dorking Union constructed a new workhouse, south of the town centre, designed by William Shearburn. The entrance block still stands and is now part of Dorking Hospital.


title: Dorking

text: A local board of health (LBH) was established in Dorking in 1881 to administer infrastructure including roads, street lighting and drainage. The LBH organised the first regular domestic refuse collection and, by mid-1888, had created a new sewerage system (including a treatment works at Pixham). The Local Government Act 1888 transferred many administrative responsibilities to the newly formed Surrey County Council and was followed by an 1894 Act that created the Dorking Urban District Council (UDC). Initially the offices of the UDC were in South Street, but in 1931 the Council moved to Pippbrook House, a Gothic Revival country house to the north east of the town centre, designed as a private residence by George Gilbert Scott in 1856.


title: Dorking

text: The Local Government Act 1972 created Mole Valley District Council (MVDC), by combining the UDCs of Dorking and Leatherhead with the majority of the Dorking and Horley Rural District. In 1984, the new council moved into purpose-built offices, designed by Michael Innes, at the east end of the town.


title: Dorking

text: Following the end of Roman rule in Britain, there appears to have been no systematic planning of transport infrastructure in the local area for over a millennium. During Saxon times, the section of Stane Street between Dorking and Ockley was bypassed by the longer route via Coldharbour and the upper surface of the Roman road was most likely quarried to provide stone for local building projects. Two routes linked the town to London, the first via the Mole crossing at Burford Bridge to Leatherhead and the second, the "Winter Road", climbed the south-facing scarp slope of Box Hill from Boxhurst and ran northeastwards to meet the London-Brighton road at Tadworth.


title: Dorking

text: The development of Guildford ( to the west) was stimulated by the construction of the Wey Navigation in the 1650s. In contrast, although several schemes were proposed to make the Mole navigable, none were enacted and transport links to Dorking remained poor. As a result, the local economy began to suffer and the town declined through the late 17th and early 18th centuries.


title: Dorking

text: The turnpike road through Dorking was authorised by the Horsham and Epsom Turnpike Act of 1755. The new turnpike dramatically improved the accessibility of the town from the capital. A mail coach operated return journeys between Dorking and London six days per week and several stagecoaches used the route daily until the mid-19th century. In contrast, the east-west Guildford-Reigate road remained the responsibility of the parishes through which it ran and only minimal improvements were made before the start of the 20th century.


title: Dorking

text: The first railway line to reach Dorking was the Reading, Guildford and Reigate Railway (RG&RR), authorised by Acts of Parliament in 1846, 1847 and 1849. Dorking station (now ) was opened in 1849 northwest of the town, initially as a temporary terminus for trains from . Local residents had expressed a preference for the station to be sited closer to the town centre at Meadowbank, but since the line passed through a deep cutting at this point it was deemed impractical to provide the necessary freight facilities at this location. Two years later a second station, now known as , was opened on the same line.


title: Dorking

text: The second railway line to serve the town was authorised by Acts of Parliament in 1862 and 1864 and was opened by the London, Brighton and South Coast Railway in 1867. A west-south connecting spur to the RG&RR was provided on opening, but was removed around 1900, before being briefly restored between 1941 and 1946 as a wartime resilience measure.


title: Dorking

text: In the late 1920s, improvements were made to the Dorking-Reigate road (now the A25), including the construction of Deepdene Bridge over the River Mole. The bypass road (now the A24) was opened in 1934 following considerable local opposition to the route, which cut through the Deepdene estate.


title: Dorking

text: A market at Dorking is first recorded in 1240 and in 1278, the sixth Earl of Surrey, John de Warenne, claimed that it had been held twice weekly since "time out of mind". The early medieval market was probably centred around Pump Corner and between South Street and West Street, but it appears to have moved east to the widest part of the High Street by the early 15th century.


title: Dorking

text: In the century following the Norman conquest, agricultural activity was focused on the lordship lands, which lay to the north of the Pipp Brook. However, as the Middle Ages progressed, woodland to the south and west of the centre was cleared enabling farms owned by the Goodwyns, Stubbs and Sondes families to expand. By the start of the Tudor period, there were at least five watermills in Dorking – two at Pixham (one on the Pipp Brook, owned by the Sondes and one on the Mole, owned by the Brownes), two close to the town centre (both owned by the manor) and one at Milton, on the road to Westcott. There may also have been a windmill on Tower Hill.


title: Dorking

text: The town flourished in Tudor times and, in the 1590s, a market house was built between what is now St Martin's Walk and the White Horse Hotel. The antiquarian John Aubrey, who visited the town between 1673 and 1692, noted that the weekly market (which took place on Thursdays) was "the greatest... for poultry in England" and noted that "Sussex wheat" was also sold. The free-draining Lower Greensand found in the Dorking area is particularly suited for rearing chickens and the local soils provide grit to assist the birds' digestive systems. The Dorking fowl, which has five claws instead of the normal four, is named after the town. Wine made from the wild cherries that grew in the town was another local speciality. A 'cherry fair' was held in July in the 17th and 18th centuries, and was revived in the 20th century at St Barnabas Church, Ranmore. Aubrey also recorded that an annual fair took place on Ascension Day.


title: Dorking

text: Chalk and sand were quarried in Dorking until the early 20th century. Chalk was dug from a pit on Ranmore Road and heated in kilns to produce quicklime. In the medieval and early modern periods, the lime was used to fertilise local farm fields, but from the 18th century onwards (and especially after the construction of the turnpike to Epsom in 1755), it was transported to London for use in the construction industry. Sand from the Folkestone Beds was quarried from several sites in the town, including at two pits in Vincent Lane.


title: Dorking

text: Caves and tunnels were also dug in the sandstone under several parts of the town. Many were used as cellars for storing wine bottles, but deeper workings followed seams of silver sand, which was used in glass making. Most of the surviving caves are privately owned and not accessible to the public. A well-known example is the cockpit beneath the former Wheatsheaf Inn in the High Street, in which fighting cocks were set against each other for sport. During the construction of the car park to the south of Sainsbury's supermarket, the builders broke through into a large cavern of unknown date, the walls of which were painted with "trompe-l'œil" pillars. Unfortunately, in order to complete the car park, it was necessary to fill in the cave with concrete. Guided tours of the caves in South Street are held on a regular basis and are organised by Dorking Museum.


title: Dorking

text: By the start of the 19th century, increasing mechanisation of agriculture was leading to a local surplus of labour. The wages for unskilled farm workers were decreasing, exacerbated by a fall in produce prices following the end of the Napoleonic Wars in 1815. Like many towns in the south of England, Dorking was affected by civil unrest among its poorest residents. In November 1830 a riot broke out and a mob of 80 attacked the Red Lion Inn in the High Street. A troop of soldiers from the Life Guards regiment was called in to restore order. In 1831 it was noted that the town (population 4711) had one of the highest rates of poor relief in Surrey.


title: Dorking

text: In early 1832, the vestry devised a supported scheme to enable young unemployed, unskilled labourers to leave the town to settle in Upper Canada. The cost of the voyage from Portsmouth to Montreal for 61 recipients of poor relief was paid by private donations, however the emigrants also received an allowance for food and clothing from parish funds. Although many were young, single men aged 14–20, a few families also joined the group. Most appear to have settled in the Toronto area, but a few are recorded as living in Kingston, Ontario.


title: Dorking

text: In 1911, the town was described in the Victoria County History as "almost entirely residential and agricultural, with some lime works on the chalk, though not so extensive as those in neighbouring parishes, a little brick-making, watermills (corn) at Pixham Mill, and timber and saw-mills."


title: Dorking

text: Although the turnpike road through Dorking had been constructed in the 1750s, the built-up part of the town had changed little by the start of the 19th century. Most of the local professional class and wealthier tradesmen lived along the three main streets (the High Street, West Street and South Street), whilst the often crowded houses of artisans and labourers tended to be in the narrower lanes and alleys. Poor sanitation was still a major problem for the poorer residents and, in 1832, a cholera outbreak was recorded in Ebenezer Place (north of the High Street), where 46 people were crammed into nine cottages.


title: Dorking

text: Nevertheless, Dorking was beginning to attract more affluent residents, many of whom had accumulated their wealth as businessmen in London. Charles Barclay (a Southwark brewery owner) and the bankers Joseph Denison and Thomas Hope (none of whom had any previous connection with the area) purchased the estates at Bury Hill, Denbies and Deepdene respectively. Higher-status individuals living closer to the town centre included William Crawford, the City of London MP, and Jane Leslie, the Dowager Countess of Rothes. Although the incoming landowners played little part in local commerce, they appear to have been the driving force behind schemes to pave streets and to provide gas lighting (both paid for by public subscription).


title: Dorking

text: Rose Hill, the first planned residential estate in Dorking, was developed by William Newland, a wealthy Guildford surgeon, who also had interests in the Wey and Arun Canal. Newland purchased the "Great House" on Butter Hill and the surrounding of land in 1831, which he divided into plots for 24 houses, arranged around a central paddock, known as "The Oval". The Great House was divided into two separate dwellings (Butter Hill House and Rose Hill House), adjacent to which a mock-Tudor arch was erected over the main carriageway entrance from South Street. Initially sales were slow, but the proposals for the building of the railway line from Redhill stimulated interest in the development in the late 1840s. Although most of the purchasers were private individuals (the majority of whom had been born outside of the local area), the Dorking Society of Friends bought one of the plots in 1845 for the construction of a meeting house. By 1861 the estate was complete.


title: Dorking

text: The arrival of the railway in 1849 catalysed the expansion of the town to the south and west. Between 1850 and 1870, the National Freehold Land Society was responsible for housing developments in Arundel and Howard Roads, as well as around Tower Hill. Poorer quality houses were built along Falkland and Hampstead Roads (many of which were replaced in the 1960s and 1970s). Holloway Farm was sold in 1870 and the first houses in Knoll, Roman and Ridgeway Roads were constructed before 1880. Houses in Cliftonville (named after its promoter, Joseph Clift, a local chemist) were also built around the same time. To the north of the High Street, smaller semi-detached and terraced houses were constructed in the 1890s for artisans in Rothes Road, Ansell Road, Wathen Road, Hart Road and Jubilee Terrace.


title: Dorking

text: No significant residential expansion took place in Dorking in the first two decades of the 20th century. In the 1920s and 1930s, the breakup of the Deepdene and Pippbrook estates (and the electrification of the railway line from Leatherhead) stimulated housebuilding to the north and east of the town, including Deepdene Vale and Deepdene Park. The sale of part of Bradley Farm (part of the Denbies estate) in the 1930s, enabled the building of Ashcombe, Keppel and Calvert Roads. The Dorking UDC intended to build housing on the rest of the farm (now Denbies Wine Estate), however their plans were interrupted by the outbreak of war and were ultimately prevented by the creation of the Metropolitan Green Belt.


title: Dorking

text: The first council housing was built in Dorking by the UDC in Nower Road in 1920 and similar developments took place in Marlborough and Beresford Roads later the same decade. In 1936, the council obtained a Slum Clearance Order to demolish 81 properties in Church Street, North Street, Cotmandene and the surrounding areas. In total 217 residents were displaced, many of whom were rehoused by the UDC in the Fraser Gardens estate, designed by the architect George Grey Wornum. The Chart Downs estate to the southeast of the town was built between 1948 and 1952.


title: Dorking

text: Controversially, in the late 1950s and 1960s, Dorking UDC constructed the Goodwyns estate on land compulsorily purchased from Howard Martineau, a major local benefactor to the town. The initial designs were by Clifford Culpin and the project was subsequently developed by William Ryder, who was responsible for the erection of the Wenlock Edge and Linden Lea tower blocks. Both the design of the buildings and the layout of the estate were praised in the early 1970s by architectural historians Ian Nairn and Nikolaus Pevsner.


title: Dorking

text: The first mention of a church at Dorking occurs in Domesday Book of 1086. In around 1140, Isabel de Warenne, the widow of the second Earl of Surrey, granted the church and a tithe of the rents from the manor to Lewes Priory in Sussex. In the 1190s, the tithe was converted to a pension of £6, which was paid annually to the Priory until at least 1291. The Priory also acquired the right to appoint the town's priest.


title: Dorking

text: It is unclear where in the town the Domesday church was located. It appears to have been replaced at some point during the 12th century (possibly by Isabel de Warenne) by a large cruciform building with a central tower. A rededication from St Mary to St Martin may have taken place around the same time. In 1334 the church was granted to the Priory of the Holy Cross in Reigate. In the late 14th century a clerestory and two side aisles were added to the nave.


title: Dorking

text: The so-called Intermediate Church was constructed in 1835–1837. It had a square tower, topped with an octagonal spire, and could seat around 1800 worshippers. Its floor level was approximately higher than that of the church it replaced, allowing the base of the medieval nave to become a crypt. In 1868–1877, the Intermediate Church was rebuilt into the present St Martin's Church, designed in the Decorated Gothic style by the architect Henry Woodyer. The spire of the current church was dedicated as a memorial to Bishop Samuel Wilberforce (who had died in 1873) and in 1905–1911 the Lady chapel was added.


title: Dorking

text: In order to accommodate the growing population in the south of the town, a second Anglican church, St Paul's, was opened in 1857 on land donated by Henry Thomas Hope. Designed by the architect, Benjamin Ferrey, it was built of Bath stone in the Decorated Geometric style. A daughter church to St Martin's, designed by Edwin Lutyens and dedicated to St Mary, was opened at Pixham in 1903.


title: Dorking

text: In the two centuries following the passing of the 1558 Act of Uniformity, many inhabitants of Dorking embraced more extreme forms of protestantism and by 1676, the parish (which had a total population of around 1500) contained 200 nonconformists. In 1620, six residents, including Williams Mullins (a cobbler) and his daughter Priscilla, joined the "Mayflower" to establish a Separatist colony in the New World. During the Civil War, the townsfolk supported the Parliamentarians, but although some of Oliver Cromwell's soldiers were billeted in Dorking, no fighting took place nearby.


title: Dorking

text: Christopher Feake, the Fifth Monarchist and independent minister, lived in the town (allegedly under a false identity) following The Restoration of the Monarchy in 1660. He may have incited some of the more radical residents to violence. Daniel Defoe, the author of "Robinson Crusoe" and a committed Presbyterian throughout his life, was educated in Dorking for five years, . He attended a school in Pixham Lane run by Revd James Fisher a non-conformist who had been ejected as Rector of Fetcham. In 1662 Fisher was involved in establishing Dorking Congregational Church, which by the 1690s was meeting in a barn on Butter Hill in South Street. The present United Reformed Church in West Street, designed by the architect William Hopperton, was built for the group by William Shearburn in 1834.


title: Dorking

text: John Wesley visited Dorking a total of nineteen times between 1764 and 1789. He opened a Methodist chapel in the town in 1777. A new church with a spire was built in South Street in 1900, however this building was sold and demolished in 1974. Since 1973, Dorking Methodists have held services at St Martin's.


title: Dorking

text: Although England had become a predominantly Protestant country during the Reformation, the families of the Earls of Arundel and Dukes of Norfolk remained Catholic. The first Catholic church in Dorking was built in the early 1870s on land owned by the fifteenth Duke of Norfolk, Henry Fitzalan-Howard and was rebuilt into the present St Joseph's Church in the mid-1890s, by the architect Frederick Walters.


title: Dorking

text: A mosque was established in Hart Road in 2006. From 1984 the building had been used as a meeting room for the Plymouth Brethren and was a synagogue for a time, before being acquired by the Dorking Muslim Community Association.


title: Dorking

text: In late 1914, Dorking became a garrison town. Empty houses were requisitioned and from January 1915 around 4000 troops were accommodated including those from the London Scottish regiment, the Civil Service Rifles and the Queen's Westminster Rifles. Training took place in the fields to the west and north west of the town. Many local residents were recruited to the Surrey Yeomanry, which (until mid-1915) was stationed at Deepdene House and at the Public Hall in West Street. Although he was aged over 40 at the start of the war, the composer Ralph Vaughan Williams enlisted in the Royal Army Medical Corps, one unit of which was based in the town.


title: Dorking

text: Of the many soldiers from Dorking who died during World War I, the youngest was Valentine Joe Strudwick. He was born in Falkland Road on 14 February 1900 and was educated at St Paul's School. He enlisted in 1915 after concealing his true age and joined the Rifle Brigade (The Prince Consort's Own). A year later, in January 1916 at the age of 15 years 11 months, he was killed in action at Boezinge, near Ypres. He is buried at Essex Farm Cemetery in Belgium.


title: Dorking

text: Empty houses in the town also provided billets for soldiers during World War II and over 3000 school children were evacuated to the Dorking area in September 1939. A local refugee committee (led by Vaughan Williams and the novelist E. M. Forster) was established to find accommodation for refugees fleeing Nazi persecution and also to support long-resident German and Czech nationals in applications to Home Office tribunals to remain at liberty in the UK.


title: Dorking

text: At the start of the war, the fortified GHQ Line B was constructed directly to the north of Dorking. This defensive line ran along the North Downs from Farnham via Guildford, before following the River Mole to Horley. The banks of the Mole were fortified with anti-tank obstacles, pillboxes and gun emplacements and an anti-tank ditch was dug from west to east across Bradley Farm (now Denbies Wine Estate). The town itself was a Class "A" nodal point and from August 1940 the 3rd Canadian Infantry Brigade (part of the VII Corps) was assigned to its defence. Pippbrook House (the then offices of the Dorking UDC) became a mobilisation centre and housed an ARP post as well as the local branch of the Women's Voluntary Service.


title: Dorking

text: Over the course of the war, 77 high-explosive bombs and 60 incendiaries were dropped by the "Luftwaffe", however only one incident (in October 1940) resulted in fatalities in the town.


title: Dorking

text: After the war, at least two Covenanter tanks were buried at Bradley Farm. The first was excavated and restored in 1977 and is now on display at The Tank Museum at Bovington in Dorset. A second was excavated in 2017 for the archaeology programme "WW2 Treasure Hunters", presented by the musician Suggs on the TV channel HISTORY. The tank was displayed at the vineyard for six months, before being removed for restoration.


title: Dorking

text: Dorking is in the Mole Valley parliamentary constituency, which has been represented in the House of Commons since 1997 by Sir Paul Beresford (Conservative). Kenneth Baker served as the local MP from 1983 to 1997 and was elevated to the House of Lords as Baron Baker of Dorking in 1997.


title: Dorking

text: Councillors are elected to Surrey County Council every four years. The town is divided between two main wards. The villages to the south east of Dorking are in a third ward:


title: Dorking

text: Five councillors represent the town on Mole Valley District Council (the headquarters of which are in Dorking):


title: Dorking

text: Dorking does not have a Town Council, however stakeholder engagement in local decision making is conducted through a number of bodies, including the Dorking Town Forum.


title: Dorking

text: Dorking is twinned with Gouvieux (Oise, France), Güglingen (Baden-Württemberg, Germany) and Sinalunga (Tuscany, Italy).


title: Dorking

text: In the 2011 Census, the combined population of the Dorking North and South wards was 11,158. The larger "built-up area" (which includes the Goodwyns estate, North Holmwood, Pixham and Westhumble, in addition to the two town wards) had a population of 17,741.


title: Dorking

text: Dorking North ward excludes Pixham and Westhumble. Dorking South ward excludes North Holmwood and the Goodwyns estate.


title: Dorking

text: Until the early 18th century, local residents obtained drinking water either directly from the Pipp Brook or from wells. In 1735, a pump was installed to lift water from a spring on the site of Archway Place, which was then distributed via wooden pipes made from bored tree trunks. Local dissatisfaction over the charges levied for the supply, prompted the vestry to reopen a well in the town centre and to install a hand pump there in 1780. The Archway Place spring became polluted by sewage in the middle of the 19th century and the works closed.


title: Dorking

text: The Dorking Water Company (DWC) was formally established in 1869, following the passing of the Dorking Water Act 1869. The company dug a well on Harrow Road East from where water was transferred by a steam-driven pump to a reservoir on Tower Hill. In 1902, a new pumping station was built on Station Road and, in 1919, the old one was converted to housing. The second pumphouse was replaced by a new works with boreholes on Beech Close in 1939. The DWC was absorbed by East Surrey Water in 1959.


title: Dorking

text: The Local Board of Health created the first sewerage system in Dorking and opened the treatment works at Pixham on the River Mole in 1888. Four years later, some 1360 houses (around 92% of the town) had been connected, necessitating an extensive rebuilding of the works in 1893. The sewerage system became the responsibility of the Thames Water Authority under the Water Act 1989.


title: Dorking

text: The town gasworks were built in 1834 by the Dorking Gas Light Company to supply gas for street lighting. From 1849, the coal required was delivered by train to Dorking West station and then transferred to the works by horse-drawn vehicle. The company was merged with that of Redhill in 1928 and became part of the East Surrey Gas Company when the industry was nationalised in 1948. After gas production ceased in 1956, the site of the works became part of the Dorking Business Park on Station Road.


title: Dorking

text: An electricity generating station was opened in 1903 in Station Road, close to the town gasworks. Initially it was capable of generating 180 kW of power, but by the time of its closure in 1939, its installed capacity was 1 MW. Under the Electricity (Supply) Act 1926, Dorking was connected to the National Grid, initially to a 33 kV supply ring, which linked the town to Croydon, Epsom, Leatherhead and Reigate. In 1939, the ring was connected to the Wimbledon-Woking main via a 132 kV substation at Leatherhead.


title: Dorking

text: A nightly patrol was established in Dorking in 1825 and in 1838 a small police force, initially with just three officers, was established under the Lighting and Watching Act 1833. This force became part of the Surrey Constabulary on its creation in 1851. A combined police station and magistrates' court complex was opened at the east end of the High Street in 1894 and the police station relocated to Moores Road in 1938. Purpose-built magistrates courts were opened adjacent to Pippbrook House in 1979 and closed in 2010.


title: Dorking

text: A volunteer fire brigade was formed in 1870. Initially based at South Street, it moved to the Public Hall at the west end of West Street in 1881. The brigade became full time in 1912 and, in 1971, it moved to a new fire station adjacent to the newly built ambulance station at North Holmwood. In 2021, the fire authority for Dorking is Surrey County Council and the statutory fire service is Surrey Fire and Rescue Service. Dorking Ambulance Station is run by the South East Coast Ambulance Service.


title: Dorking

text: Dorking Cottage Hospital, opened in 1871 in South Terrace, was the first hospital in the town. It was merged in 1948 with the adjacent County Hospital, which had evolved from the Union Workhouse and Poor Law Infirmary, to form Dorking General Hospital. Since 2004, Dorking Hospital has been run as a community hospital by a consortium of local GP groups that provides Outpatient Services for the local area. The nearest accident & emergency departments are at Epsom Hospital () and East Surrey Hospital (). As of 2020, there are GP practices on Reigate Road and South Street.


title: Dorking

text: The A24 London-Worthing and the A25 Guildford-Sevenoaks roads intersect at Deepdene Roundabout on the eastern side of Dorking. The one-way system in the town centre was introduced in 1968.


title: Dorking

text: The Epsom-Horsham and Guildford-Reigate railway lines cross to the northeast of Dorking, but there is now no physical connection between the two. The town is served by three railway stations. is managed by Southern and is served by trains to via , to via and to . and stations are managed by Great Western Railway and are served by trains to via and to via .


title: Dorking

text: Route 93 from Dorking to Horsham via Goodwyns and Holmwood Park is run by Metrobus on behalf of Surrey County Council.


title: Dorking

text: The Greensand Way, a long-distance footpath from Haslemere, Surrey to Hamstreet, Kent, passes through the south of Dorking. The route approaches the town centre from the east, passing over The Nower, then crossing the junction between South Street and Horsham Road. It climbs through the Glory Wood, before crossing Deepdene Terrace. The North Downs Way, between Farnham and Dover, passes approximately to the north of Dorking. Dorking station is the southern terminus of the Mole Gap Trail, which starts at .


title: Dorking

text: There are five primary schools in Dorking, the oldest of which is Powell Corderoy School. It was founded in 1816 as The Dorking British School, and its original premises were in West Street; but twenty years later it moved to North Street. Towards the end of the nineteenth century, the school had expanded and the funds for a new building in Norfolk Road were raised by Edith Corderoy and Mr T. Powell. The new site was opened in 1898 and the school adopted its present name in 1906. The school moved to its current location in Longfield Road in 1968.


title: Dorking

text: St Martin's Primary School was founded as a National School by the vestry in the 1830s, however there is thought to have been a school located in the transepts of the parish church as early as the 17th century. The National School was moved from the grounds of the church to West Street in 1862. The Middle School relocated to Ranmore Road in 1969 and was joined by the First School in 1985. The Pixham First School was founded in 1880 by Mary Mayo and was built to a design by Gilbert Redgrave. St Paul's Primary School was founded in 1860.


title: Dorking

text: St Paul's School was designed by the architect, Thomas Allom, and admitted its first pupils in March 1860. The infants department opened in 1872 and, from that year, the school educated children aged from 5 to 13. Today, St Paul's is a Church of England Voluntary Aided Primary School and educates children from the ages of 5 to 11.


title: Dorking

text: St Joseph's Catholic Primary School was founded in 1873 by Augusta Fitzalan-Howard, Duchess of Norfolk. The first premises were in Falkland Grove adjacent to St Joseph's Church. The school was run by nuns of the Servite Order from 1887 to 1970, when it moved to its present site in Norfolk Road, which had been vacated by Powell Corderoy School.


title: Dorking

text: St John's Primary School was founded in 1955 on the Goodwyns housing estate to the south of the town. It was known as The Redlands Junior School until August 1999.


title: Dorking

text: New Lodge School, an independent prep school formed in 2002 from the merger of Stanway School and Nower Lodge School, closed in 2007.


title: Dorking

text: The Ashcombe School is a coeducational secondary school, north of the town centre. It traces its origins to the Dorking High School for Boys, founded in 1884, and the St Martin's High School for Girls, opened in 1903. In 1931, the two schools were merged to become the Dorking County School and moved to a new site in Ashcombe Road. In 1959 the Mowbray County Secondary Modern for girls was opened on an adjacent site. The two schools were combined to create the Ashcombe School in 1975.


title: Dorking

text: The Priory School opened as the County Secondary Modern Mixed School in September 1949. It was initially based at the Dene Street Institute, but moved to its present location in West Bank within a few years. In 1959, the girls were transferred to the Mowbray School in the Ashcombe Road, and Sondes Place continued as a boys-only school. In 1976 it became a mixed comprehensive school and was renamed the Priory School in 1996.