The item is a 6 inch transit circle. The transit circle is an instrument used to determine the declination of stellar onjects. It consists of a circular scale kept perpendicular to the rotating axis of a telescope tube.

This item was an instrument used for measuring the intensity of a light source. It uses a light-sensing device that is calibrated to express intensity in a standard unit. Some optical elements such as lens etc. are also employed to incerase the sensitivity of the instrument.

The letter was reply to D.O.No.2440 of the 8th instant, the R.A. clamp at Lahore is intended to be used with two cords and it was explained to Chowla. Further he mentioned about transit instrument and chronograph are extremly shoddy and not in accordance with specification.

The letter was to inform G. S. Chowla the dislikeness of Dr.Gilbert T. Walker for the clamping arrangement made in R.A., and asking for the required arrangement to take make the clamping arrangements right.

This item was a stellar object requires two coordinates to locate it on the sky, as the sky is a two-dimensional plane. One of these coordinates known as declination. This is similar to the two co-ordinates viz. latitude and longitude, defining a point on the surface of the earth. The transit circle is an instrument used to determine the declination of stellar onjects. It consists of a circular scale kept perpendicular to the rotating axis of a telescope tube.