Correspondence concerning the proposal to the Board of Visitors for a new universal transit circle, to be called the New Altazimuth Instrument, 1892, includes preliminary correspondence with the Admiralty and the estimated cost of constructing the instrument.
Correspondence informing the Admiralty of the resolution of the Board of Visitors in favour of the new instrument and correspondence with the Admiralty asking that they authorise the construction of the instrument, 1892-1893. The letters include the sanction from the Admiralty to build the instrument and tenders and specifications from Troughton and Simms.
Correspondence with Troughton and Simms concerning the construction of the New Altazimuth Instrument, including copies of the contract, tender, specifications and rough diagrams, 1892-1898.
Experimental observations and notes made with the New Altazimuth Instrument, 1896.
Observations made with the New Altazimuth Instrument, 1897.
Original rough drafts, sketches, plans and memoranda concerning the building of the New Altazimuth Instrument, 1892.
Fragile, loose plans of the New Altazimuth Instrument, 1894-1895, including:
1. 'Section of Circles, 3ft Diameter', 1894.
2. Detailed plan showing collimators 'Scale 1½" to one foot', signed by G. Cowdry, dated 24 December 1895.
3. Two black and white photographs of the New Altazimuth Instrument: 5½" x 7½" (in good condition) and 6½" x 8½" (in poor condition, faded and spotted).