The five observatories, which were built and finished by Jayasinha, still exist in a state more or less perfect; they were erected at Jeypoor, Matra, Benares, Oujein, and Delhi.
The next observatory, in point of size and preservation, is that at Oujein; it is situated at the southern extremity of the city, in the quarter called Jeysingpoorah, and where are still the remains of a palace of Jayasinha, who was subahdar of Malwa in the time of Mahommed Shah. The observatory at Oujein has since been converted into an arsenal and foundry of cannon.
At Matra, the remains of the observatory are in the fort which was built by Jayasinha on the banks of the Jumna.
The observatory at Delhi is situated without the wall of the city, at the distance of one mile and a quarter. It consists of several detached buildings:—
1. A large equatorial dial: its form is pretty entire, but the edges of the gnomon, and those of the circle on which the degrees were marked, are broken in several places. This is the instrument called by Jayasinha semrat-yunter (the prince of dials). It is built of stone, but the edges of the gnomon, and of the arches where the gradation was, were of white marble; a few small portions of which only remain.
2. At a little distance from this instrument, towards the north-west, is another equatorial dial; more entire, but smaller and of a different construction. In the middle stands a gnomon, which, as usual in these buildings, contains a staircase up to the top. On each side of this gnomon are two concentric semicircles, having for their diameters the two edges of the gnomon; it is evident that they represent meridians. On each side of this post is another gnomon, equal in size to the former; and to the eastward and westward of them are the arches on which the hours are marked.
3. The north wall of this building connects the three gnomons at their highest end; and on this wall is described a graduated semicircle, for taking the altitudes of bodies that lie due east, or due west, from the eye of the observer.
4. To the westward of this building, and close to it, is a wall, in the plane of the meridian, on which is described a double quadrant, having for the centres the two upper corners of the wall, for observing the altitudes of bodies passing the meridian, either to the north or south of the zenith.
5. To the southward of the dial are two buildings, named Ustuánah. They exactly resemble one another, and are designed for the same purpose, which is, to observe the altitude and azimuth of the heavenly bodies. They are two in number, on purpose that two persons may observe at the same time, and so compare and correct their observations.
These buildings are circular; and in the centre of each is a pillar, of the same height as the building itself, which is open at top. From this pillar to the height of about three feet from the bottom, proceed radii of stone, horizontally, to the circular wall of the building.