Brunsviga 'System Trinks' Mechanical Calculator, by Grimme Natalis & Co., German, 1933

A rectangular wooden case with a removable lid that can be locked with a key on the side. There is a copper alloy handle above the key. Inside is a black iron alloy Brunsviga 'System Trinks' mechanical calculator that is covered with a brown fabric dust cover. The mechanical calculator has a row of 10 numbers next to a row of 18 numbers at the bottom and a set of 9 dials above these rows. There is a crank handle on the right hand side. There is a metal plate in the base of the case that reads: "BLOCK AND ANDERSON LTD. Brunsviga House, 30-31, Farringdon Street, LONDON, E.C.4. Tel: Central 5363 MANCHESTER BIRMINGHAM NEWCASTLE GLASGOW SHEFFIELD LEICESTER BELFAST."