Zenith sector designed by Sir George Airy and used on Principal Triangulation from 1842-1850 Zenith sector, British, 1840 1840
Glass parts for Zenith sector designed by Sir George Airy and used on Principal Triangulation from 1842-1850 Part of Zenith Sector, British, 1840 1840
Main part of zenith sector designed by Sir George Airy and used on Principal Triangulation from 1842-1850 Part of Zenith Sector, British, 1840 1840
[Ms. letter] 1876 Nov 3, Playford near Ipswich [to] R. Anderson, Secretary to Home Office / G.B. Airy. [2p. on 1 leaf. He returns the Report (of the Commissioners appointed to inquire into the state of the Royal Observatory at Edinburgh), suggesting an alteration for Lord Lindsay to approve. With accompanying note (1p.) reiterating this. Anderson was Secretary to the Home Office. The Report of the Commission, of which Airy was a member, was published in 1877] Ms. letter 1876 Nov 3 1876