The fond contain correspondance of M. K. Vainu Bappu with C. V. Raman and mentors, donated by Mrs. Yemuna Bappu to IIA archives.

The fond contain correspondence regarding the Astronomical Observatory at Lahore. The letter is from the Director of Kodaikanal & Madras Observatories to the Registrar, Panjab University, Lahore, giving suggestions for the proposed Astronomical Observatory to be built in Lahore. The letter has suggestions about transit instruments and a 7-inch equatorial telescope. A sketch of the roofing complex is also attached.

The fond contain correspondence regarding the proposal to build a General Hospital on the Spur Tank and 'Air blast' in the mines of Mysore.

This Fond is related to Magnetic Observatory of Kodaikanal

The fond contains correspondence related to the Periyakulam Observatory.

The fonds contain circulars and letters from the Meteorological Department, Government of India.

All letters were related to Poona and Kodaikanal & Madras Observatory. In this fond, there are a total of 37 items.

This fond contains materials related to C. M. Smith that has general local office materials including letters of all local government and administrations. The letters pertaining to conference proceedings, and correspondences from International Scientists. A large portion of the collection was associated with information on observation.

This fond contains official letters related to Charles P. Butler during 1903-1904. It includes communications with the Meteorological Reporter, the Government of India and Director General of Indian Observatories, Simla, and the Officer Commanding Royal Engineers, Madras.

The fond contains correspondence between E. C. J. Bond, the officer-in-charge, No. 18 party (Magnetic), Survey of India, and the Director of the Kodaikanal and Madras Observatories during 1919-1920. The official letters are about the magnetic observations from the Kodaikanal Magnetic Observatory. The observations have been taken from the Kodaikanal Observatory and used to send to The Survey of India office for scientific purposes. This fond consists of 7 letters sufficient to understand the cooperation between The Survey of India and The Kodaikanal Observatory.