Correspondence with Troughton and Simms concerning the order, construction and testing of the photographic spectroscope, 1895-1901.

Miscellaneous correspondence concerning the repair and replacement of spectroscopes, 1885-1895. The correspondents are J. Brashear, J. Browning, Messrs Harvey and Peak, E.W. Maunder and J. Simms.

Memoranda concerning spectroscopes, 1886-1896: 1. Oxford Reversion Spectroscope; 2. Half Prism Spectroscope; 3. Suggestions with regard to the spectroscope for the new 28" refractor for measurement of the displacement of the lines in stellar spectra; and 4. Half Prism Spectroscope.

Correspondence concerning the repair and adjustment of micrometers, 1890-1900. The correspondents are G. Criswick, F.W. Dyson, M. Maw, Messrs Troughton and Simms, and H.H. Turner.

Memoranda, 1902-1904: 1. Micrometer for Eros Photographs, 2. Glass Diaphragm for new micrometer, 3. New micrometer for Eros photos, 11 December 1902, 4. Measures of stars with n ew micrometer, 5. New micrometer for Eros photos; 6. Notes on alterations required, and 7. Drawing of glass diaphragm in focal plane of micrometer for measuring Eros.

Correspondence with Troughton and Simms, 1902-1904.

Correspondence with J. Dallmeyer Ltd on a telephotographic negative 3" lens for the Thompson Photoheliograph, 1896.

Correspondence with P. Meagher concerning the purchase of camera box slides for the Thompson Photoheliograph, 1896

Correspondence with Messrs Ross and Co. concerning the purchase of new photographic lenses, a new camera box and photographic slides, 1900.

Correspondence with Troughton and Simms concerning a required extension of the tube of the 9" Thompson Photographic Telescope, 1900.

Correspondence with Ross and Co. concerning plate holders for photoheliographs, 1901.

Correspondence with the Royal Alfred Observatory, Mauritius, concerning the exchange of a photoheliograph with the Royal Observatory, Greenwich, 1901.