page_title: Scaphe
section_title: History
hierarchical_section_title: Scaphe / History
caption_attribution_description: English: Sundial with Aramean Inscription, Sandstone, 1st. Cent. B.C., found in Madain Saleh; Istanbul Archaeological Museums - Museum of the Ancient Orient, Inv. No. 7664 Deutsch: Sonnenuhr (Typ:Skaphe) mit aramäischer Inschrift aus der nabatäischen Nekropole Madain Saleh in Saudi Arabien Français&#160;: Cadran solaire de type Skaphe en grès du 1er. Siècle AV. J.C. avec inscription araméenne de la nécropole nabatéenne Madain Saleh en Arabie Saoudite, trouvé dans Madain Saleh - Musées archéologiques d'Istanbul - Musée de l'Orient antique, Inv. N ° 7664.
context_page_description: The scaphe was a sundial said to have been invented by Aristarchus of Samos. There are no original works still in existence by Aristarchus, but the adjacent image is an image of what it might have looked like; only his would have been made of stone. It consisted of a hemispherical bowl which had a vertical gnomon placed inside it, with the top of the gnomon level with the edge of the bowl. Twelve gradations inscribed perpendicular to the hemisphere indicated the hour of the day.
context_section_description: Greeks and Romans used large stone sundials based on "a partial sphere or scaphe,” the shadow of the tip of the gnomon was the time-telling index. These dials could in theory tell time accurately if carved to a true sphere and correctly calibrated for a given site.
  It took a skilled stone worker and a great deal of time and money to create a sundial. So only wealthy citizens could afford this elaborate contraption, and it was often for their villas or as donations for erection in the town forum. There was a need for cheaper dials that ordinary laborer could construct. But even if it were easier to make, the question of calibrating the scaphe still posed a problem.
  The problem of projecting the three-dimensional scaphe dial upon a vertical or horizontal plane was addressed by a number of distinguished nineteenth-century mathematicians, each of whom presumably solved it to his own personal satisfaction. Unfortunately, their publications are so complex, long-winded, and obscure that they were virtually inaccessible to antiquaries and—it would appear from the replication of effort—even to their own (unacknowledged) colleagues. The spherical trigonometry required for the latter endeavor is really quite basic, and the calculations tedious rather than difficult. The availability of computer-generated graphics has, of course, completely altered the situation. A Fortran program was written for the VAX computer at the University of Leicester that enabled vertical or horizontal dials to be plotted for any latitude.
caption: Sundial from Madain Saleh
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