This letter was about the abstract bill of charges that were incurred for the carriage of "Siderostat" part of the spectroheliograph from Madras to Kodaikanal and request the payment may be made as early possible.

This letter is from R.E.V. Arbuthnot to the secretary to the Government of Madras, Public Works Department, regarding the erection of a building to house the photo spectroheliograph which was being procured from England for the use of the Kodaikanal Solar Physics Observatory.

The letter was a reply to Turner's letter, that discusses on the spectroheliograph observations

Charles P. Butler sent this letter to Gilbert T. Walker on installing a spectroheliograph in the Kodaikanal Observatory. The letter was sent from the Royal College of Science, London, on 3rd June 1904.

This letter was with reference to his Annual Indent for Stores forwarded in the year 1905 and submitting points towards it. The letter also speaks on photographic plates, lower power microscope and spectroheliograph.