Collection of three platinotype prints of engravings in, 'Selenographia' by Johannes Hevelius, 1647 showing sunspots observed through a telescope. Collection of three platinotype prints of engravings in
One of six calotype prints, showing a 13-inch reflecting telescope with a speculum mirror [see 1897-13] made by James Nasmyth in an open framework tube and an altazimuth mounting. Taken by him at the front of his large house, 'Hammerhurst' near Penshurst in Kent and undated 1858-1865. Calotype print by Nasmyth of his portable 13-inch reflecting telescope on the lawn in the grounds of his home, 1858-1865
One of six calotype prints, showing a 20-inch reflecting telescope with speculum mirror [Nasmyth focus] on a modified altazimuth mounting [see 1933-21] built by James Nasmyth at his Patricroft works, Manchester. Taken by him at of his large house, 'Hammerhurst' near Penshurst in Kent and dated 29th May 1866. Calotype print of Nasmyth's 20-inch reflecting telescope, 1866