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.

This letter was about the BARC image convention and the M. K. Vainu Bappu's visit.

This letter was about spectra for H & K emission and sending a report on the condition of the Zeiss double monochromator.

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 letter was to inform that C. V. Raman was greatly obliged for M. K. Vainu Bappu's letter of the 8th July 1954. He got one of the Bausch and Lomb catalogues and was very favourably impressed by it and intend to go ahead and purchase one or more of these gratings for his work.

This letter was asking question on using telescope mirrors made of cast aluminium or other light metal, which could be cheap and easy to make and also what kind and size of grating, its makers and price to building a solar observatory.

The letter is about water vapour observations. Bappu was also asking whether the point source lamp was used. He also mentioned that he would be in Bangalore on April 27.

This letter was about the performance of the Newton spectrograph, prepatory work and observations on sky.

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 unused telescopes. It was unfortunate to hear that the telescopes that allowed scientists to photograph the Sun was now lying unused and gathering dust in a mechanical workshop at IIA, along with two other instruments that have met the same fate. According to a senior scientist at the institute, these instruments were dumped in the workshop and only brought out and exhibited during visits by VVIPs.