It is here not a question of interruptions of the labour-process necessitated by natural limitations of the labour-power itself, although we have seen to what extent the mere circumstance that fixed capital factory buildings, machinery, etc. lies idle during pauses in the labour-process, [See: Karl Marx, Capital, Vol. I, pp. 256-63. Ed.] became one of the motives for an unnatural prolongation of the labour-process and for day-and-night work. We are dealing here rather with interruptions independent of the length of the labour-process, brought about by the very nature of the product and its fabrication, during which the subject of labour is for a longer or shorter time subjected to natural processes, must undergo physical, chemical and physiological changes, during which the labour-process is entirely or partially suspended. For instance grape after being pressed must ferment awhile and then rest for some time in order to reach a certain degree of perfection. In many branches of industry the product must pass through a drying process, for instance in pottery, or be exposed to certain conditions in order to change its chemical properties, as for instance in bleaching. Winter grain needs about nine months to mature. Between the time of sowing and harvesting the labour-process is almost entirely suspended. In timber-raising, after the sowing and the incidental preliminary work are completed, the seed requires about 100 years to be transformed into a finished product and during all that time it stands in comparatively very little need of the action of labour. In all these cases additional labour is drawn on only occasionally during a large portion of the time of production. The condition described in the previous chapter, where additional capital and labour must be supplied to the capital already tied up in the process of production, obtains here only with longer or shorter intervals. In all these cases therefore the production time of the advanced capital consists of two periods: one period during which the capital is engaged in the labour-process and a second period during which its form of existence that of an unfinished product is abandoned to the sway of natural processes, without being at that time in the labour-process. Nor does it matter in the least here and there. The working period and the production period do not coincide in these cases. The production period is longer than the working period. But the product is not finished, not ready, hence not fit to be converted from the form of productive into that of commodity-capital until the production period is completed. Consequently the length of the turnover period increases in proportion to the length of the production time that does not consist of working time. In so far as the production time in excess of the working time is not fixed by natural laws given once and for all, such as govern the maturing of grain, the growth of an oak, etc., the period of turnover can often be more or less shortened by an artificial reduction of the production time. Such instances are the introduction of chemical bleaching instead of bleaching on the green and more efficient drying apparatus. Or, in tanning, where the penetration of the tannic acid into the skins, by the old method, took from six to eighteen months, while the new method, by means of an air-pump, does it in only one and a half to two months. (J. G. Courcelle-Seneuil, Trait th orique et pratique des entreprises industrielles, etc., Paris, 1857, 2-me d.) The most magnificent illustration of an artificial abbreviation of the time of production taken up exclusively with natural processes is furnished by the history of iron manufacture, more especially the conversion of pig iron into steel during the last 100 years, from the puddling process discovered about 1780 to the modern Bessemer process and the latest methods introduced since. The time of production has been brought down tremendously, but the investment of fixed capital has increased in proportion. A peculiar illustration of the divergence of the production time from the working time is furnished by the American manufacture of shoe-lasts. In this case a considerable portion of the unproductive costs arises from having to hold the timber at least eighteen months before it is dry enough to work, so as to prevent subsequent warping. During this time the wood does not pass through any other labour-process. The period of turnover of the invested capital is therefore not determined solely by the time required for the manufacture of the lasts but also by the time during which it lies unproductive in the shape of drying wood. It stays 18 months in the process of production before it can enter into the labour-process proper. This example shows at the same time that the times of turnover of different parts of the aggregate circulating capital may differ in consequence of conditions which do not arise within the sphere of circulation but owe their origin to the production process. The difference between production time and working time becomes especially apparent in agriculture. In our moderate climates the land bears grain once a year. Shortening or lengthening the period of production (for winter grain it averages nine months) itself depends on the alternation of good and bad seasons, and for this reason cannot be accurately determined and controlled beforehand as in industry proper. Only such by-products as milk, cheese, etc., can steadily be produced and sold in comparatively short periods. On the other hand, working time data are as follows: In most branches of industry proper, of mining, transportation, etc., operations proceed evenly, the working time being the same year in year out and the outlay of capital passing daily into the circulation process being uniformly distributed, apart from such abnormal interruptions as fluctuations of prices, business dislocations, etc. Likewise the return of the circulating capital or its renewal is evenly distributed throughout the year, market conditions otherwise remaining the same. Yet there is in the course of the various periods of the year the greatest inequality in the outlay of circulating capital in such capital investments in which the working time constitutes only a part of the production time, while the return takes place only in bulk at a time fixed by natural conditions. If the scale of business is the same, i.e., if the amount of advanced circulating capital is the same, it must be advanced in larger quantities at a time and for longer periods than in enterprises with continuous working periods. There is also a considerably greater difference here between the life of the fixed capital and the time in which it really functions productively. Due to the difference between working time and production time, the time of employment of the applied fixed capital is of course likewise continually interrupted for a longer or shorter time, for instance in agriculture in the case of working cattle, implements and machines. In so far as this fixed capital consists of draught animals, it requires continually the same, or nearly the same, expenditure for feed, etc., as it does during the time they work. In the case of dead stock non-use also brings on a certain amount of depreciation. Hence the product is in general increasing in price, since the transfer of value to it is not calculated according to the time during which the fixed capital functions but according to the time during which it depreciates in value. In branches of production such as these, the idling of the fixed capital, whether combined with current expenses or not, forms as much a condition of its normal employment as for instance the loss of a certain quantity of cotton in spinning; and in the same way the labour-power expended unproductively but unavoidably in any labour-process under normal technical conditions counts just as well as that expended productively. Every improvement which reduces the unproductive expenditure of instruments of labour, raw material, and labour-power also reduces the value of the product. In agriculture we have a combination of both the longer working period and the great difference between working time and production time. Hodgskin rightly remarks: The following passage in the above quotation from Kirchhof in particularly worthy of note: The same applies to stock raising. A part of the herd (supply of cattle) remains in the process of production, while another part is sold annually as a product. In this case only a part of the capital is turned over every year, just as in the case of fixed capital: machinery, working cattle, etc. although this capital is a capital fixed in the process of production for a long time, and thus prolongs the turnover of the total capital, it is not a fixed capital in the strict definition of the term. What is here called a supply a certain amount of standing timber or livestock exists relatively in the process of production (simultaneously as instruments of labour and material of labour); in accordance with the natural conditions of its reproduction under proper management, a considerable part of this supply must always be available in this form. A similar influence on the turnover is exerted by another kind of supply, which is productive capital only potentially, but which owing to the nature of this economy, must be accumulated in more or less considerable quantities and hence advanced for purposes of production for a long term, although it enters into the actual process of production only gradually. In this class belongs for instance manure before it is hauled to the field, furthermore grain, hay, etc., and such supplies of means of subsistence as are employed in the production of cattle. We shall see later (Volume III), what senseless theories MacCulloch, James Mill, etc., arrived at as a result of the attempt to identify the production time diverging from working time with the latter, an attempt which in turn is due to a misapplication of the theory of value. The turnover cycle which we considered above is determined by the durability of the fixed capital advanced for the process of production. Since this cycle extends over a number of years it comprises a series of either annual turnovers of fixed capital or of turnovers repeated during the year. In agriculture such a cycle of turnovers arises out of the system of crop rotation.
Economic Manuscripts: Capital: Volume Two