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 letter informing estimate about the provision for wooden floors to the bedrooms also and for tiling the roofo the outhouses to the quarters

This item was an instrument used in surveying land, alignment, testing, and calibrating optical Instruments. It is basically a refracting telescope. Whose optical elements tilt angles with high accuracy of the order of arcsecs.

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.

The fond contains Results of observations of the fixed stars made with the Meridian Circle at the Government Observatory , Madras

The item contains six telegraphs from the Telegraph Director in Bombay, with four directed towards Kodaikanal and two towards Chetput(Chennai). One is a request for a copy of the magnetogram taken during the magnetic storm.

This item was a optical instrument named as Stereoscope. Stereoscopes are apparently those optical devices that help to view the two images separately and with relaxed eyes. There are two types of stereoscopes as: lens or pocket stereoscopes and mirror stereoscopes. Lens or pocket stereoscopes are great for viewing the whole overlap area of prints up to 9 cm × 13 cm or parts of larger patterns. On the other hand, mirror stereoscopes were designed to accept standard 23 cm × 23 cm metric air photos and work well with A4/US letter-sized prints. Most models come with magnifying options up to eight times, which is pretty impressive. One cool thing about mirror stereoscopes is that they are large enough to allow the analyst to draw beneath them, so it is possible to trace objects identified in the stereoview with a pen onto one of the images or a transparent overlay. However, it's important to remember that this sketch wouldn't have the geometric properties of a map as it contains all distortions present in the base image.

The item comprises observations notes of the separate results of Madras Meridian Circle Observation by N. R.Pogson in 1864 and 1875.

The letter is to the Sub Divisional Officer, PWD, Kodaikanal, requesting to arrange for the painting of the thermometer house, magnetic hut and office room during that year.

The book contains the results of observations of the fixed stars made with the meridian circle at the government observatory Madras in the years 1868, 1869 and 1870 under the direction of Norman Robert Pogson, government astronomer at Madras.