细节
A collection of steam engine indicators,
including a Richards patent by Elliot Bros, patent No.782 with springs, rulers and valve in mahogany case; another by Dobbie McInnes Ltd in fitted wooden box; another, incomplete, by McNaught, Glsgow; a miners gas tester by Davis, Leeds in fitted wooden box; and a test set of Bourdon Patent pressure gauges with trade label inscribed Negretti & Zambra, Sole Agents (5)
including a Richards patent by Elliot Bros, patent N