9. UNIVERSAL EQUATORIAL SUNDIAL

This sundial was produced after a European prototype. It consists of a circular plate, horizontal placed, of 172 mm diameter. This plate is set up on four legs of 47 mm height. The legs have adjustable screws so that the instrument can be made level. To the horizontal plate is hinged another circular plate of 139 mm diameter. The inclination between the two plates can be adjusted, against a graduated arc, in accordance with the local latitude. When the angle of inclination is equal to the latitude of the place, then the second plate will be in a plane parallel to the plane of the celestial equator. Therefore, this sundial is called “equatorial” sundial. Since the instrument can be used at different latitudes, it is called “universal”.

Time is measured on the second plate on which a gnomon throws its shadow upon a scale of hours. These hours are marked by Persian numerals in black enamel and read from 6 a.m. to noon; and then from 1 p.m. to 6 p.m. each hour is subdivided into units of 10 minutes. As in the previous sundial by Mangaran, here too is a built-in compass for proper orientation of the sundial.

This is a well-crafted piece; the gnomon can be folded back flush with the surface of the dial. The dial can be compressed to the level of the base plate. Other raised parts can also be folded back. Thus it makes an excellent portable sundial. There is no maker’s inscription but it is certain that it was manufactured in the nineteenth century.