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This item was an instrument used to measure time. A wire rope is wound around a drum which unwinds in a fixed time under gravity. A maker which moves horizontally, marks out the time elapsed on a linear scale. This instrument was used before the invention of the pendulum clock for Astronomical measurements at the Madras Observatory.

The title "Les Observatoires Astronomiques" can be translated to Astronomical Observatories. This book consists of astronomical observations from the Royal Observatory of Belgium. It is written by P.Stroobant, E .Delporte, J. Delvosal and F. Moreau, and H. L. Vanderlinden. It is published in 1836

This item was a magnetic compass which was used by M.K.Vainu Bappu during the visit to Kavalur for site survey. The magnetic compass is a tool used for determining direction on the surface of the Earth. It operates by using a magnetic pointer that aligns itself with the Earth's magnetic field. This type of compass is the oldest and most commonly used in various forms of transportation such as aircraft, ships, and land vehicles. The Earth's magnetic field acts as an enormous bar magnet with a North-South field that causes freely moving magnets to take on the same orientation. Although the direction of the Earth's magnetic field is not entirely parallel to the North-South axis of the globe, it is close enough to make an uncorrected compass a reasonably good guide. The inaccuracy, known as variation (or declination), varies in magnitude from point to point on Earth.

This item was about the photograph of granite pillar in meteorology department compound at Nungampakkam, Chennai as seen today. In the compound of the Meteorology Department in Chennai, there is a 15-foot tall granite pillar weighing 10 tons. This granite pillar is part of the Regional Meteorological Centre in Chennai and is preserved as a monument. This is the place where Madras Observatory was existed.

This item was about the Goldingham working with a Kater's Pendulum hung in front of a haswell clock in the Observatory. The second assistant Thiruvenkatachary, is reading the clock, while the first assistant Srinivasachary, sitting near the 18 ft granite pier, is noting down the reading.

This item was about the map of part of the environs of Madras showing the relative positions of the Observatory house station and the guns. This map was made by J.Goldingham who was F.R.S. in Madras Observatory and the map was published in Madras Observatory papers in 1826 on page no. 177.

This fond was about pendulum clock used at the Madras Observatory manufactured sometimes in 1786. The clock is now in Kodaikanal Solar Observatory and still in working condition.

These photographic slides contains drawings of porters, telescopes, and other astronomical instruments.

These photographic slides contains different images of Mcdonald observatory.

These photographic slides contain the images of the spectrometer, and Ondrej telescope related to the Optical Science Department of Royal Observatory, Edinburgh.