The Astronomical Observatories of Jai Singh c6.s1.17

c6.s1.17

⁶ Ar. ‘iẓādah, ‘door post’; Dioptra, Mediclinium, Verticulum, Alidade, etc. Tanner (1587) describes the alhidade thus: “Altriada or mediclinium, in which are put two little pins or tables to take the height of the sun in the day and of the stars at night, of which one side goeth through the centre of the astrolabe is called the line of trust, because it bringeth credit of things practised there.”