1872 patent cast steel bell, by Vickers Sons and Company Limited, Sheffield, Yorkshire, England, 1872-1874 1872 patent cast steel bell, one of three 1872-1874
"Loose-leaf booklet containing text, photographs and drawings of two calendar regulator clocks with gravity escapement made by Henry Hall Summers, c.1921-23" Calendar regulator clock drawings and photographs 1921-1923