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.