The Astronomical Observatories of Jai Singh c6.s1.t1.6

c6.s1.t1.6

The almucantarats are circles of altitude,¹ the almucantarat of zero altitude being the horizon (*EHW* in plate V). In the diagram almucantarats are drawn for 60°, 40°, 20° (as well as the horizon, 0°) and are marked *a*₆₀, *a*₄₀, *a*₂₀. The number of almucantarats varies in different astrolabes: if there is one for each degree of altitude, the instrument is called *tāmm* or ‘complete’; if for every other degree, it is termed *niṣfi*, ‘bipartite’ and so on. Jaipur A and B (figures 5 and 6) are *tāmm* or ‘complete’; Herāt C (figures 17 and 18) is *niṣfi*; while ‘Jaipur D’ (figure 10) is *sudsi* or sexpartite.