Page:Wanderings of a Pilgrim Vol 2.djvu/247

 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.

6. Between these two buildings and the great equatorial dial is an instrument called shamlah. It is a concave hemispherical surface, formed of mason work, to represent the inferior hemisphere of the heavens.

The best and most authentic account of the labours of Jayasinha for the completion of his work and the advancement of astronomical knowledge, is contained in his own preface to the Zeej Mahommedshahy; from which the following extract is a literal translation:—