The letter is from Thomas Royds, assistant Director of Kodaikanal Observatories, to the editors of the astrophysical journal regarding a paper. It states that the manuscript of the paper on "The different character of spectrum lines belonging to the same series for its publication in the astrophysical journal.

The letter certifies that P. R. Chidambara Ayer has been working in Solar Physics Observatory for the last ten years under the supervision of Thomas Royds. It mentioned that certificates related to education and work experience and copies of the thesis on " The distribution of Sun-spot in longitude" were also attached with the letter. It is an experience certificate for approval for submitting P. R. Chidambara Ayer's thesis.

The letter was about the submission of MSc. Thesis of P. R. Chidambara Ayer to the Madras University. He is requesting to take immediate action on the further process of thesis submission before the end of November 1930.

The item was a letter by P. R. Chidambara Ayer to The Registrar of the University of Madras on submitting an MSc.Thesis. The letter was sent in 1929.

This letter was about conversing the reply of Christie on heating to C. M. Smith.

This letter was reply to the questions contained in the letter dated July, 1906, from Prof. Schuster on behalf of the International Union for Solar Research.

This document was about brief description of Dr.M. K. Vainu Bappu's academic career, membership, participation in committees and societies, the medals awarded and the research area for which he contributed.