SCHMALCALDERS PATENT PRISMATIC COMPASS c. 1826 VERY RARE GEORGIAN ANTIQUE BRASS. A rare and very beautiful Georgian compass, a Schmalcalder’s Patent prismatic, serial no. 2150 C, made in London c. The compass card is marked’Schmalcalder’s Patent, 399 Strand, London’. With a hand-drawn green compass card, lacquered brass case and lid, prism and vane sights, transit lock, and manual brake. His patent design of 1812, which introduced the idea of using an optical prism, combined with a sighting vane, to improve accuracy when taking bearings, is still in use today. Schmalcalder’s innovation was a development of the work of Henry Kater. In 1811 Kater developed a design using a mirror and sighting vane. His design was then manufactured by Thomas Jones. Schmalcalder, who also knew Thomas Jones, is believed to have seen Kater’s new compass at Jones’ premises, and this gave him the idea for his own prismatic version. Schmalcalder moved swiftly to have prototypes of his own design made by Jones, which he then went on to patent. Winning the race to patent his innovation, Schmalcalder’s compass completely eclipsed Kater’s earlier design. Schmalcalder continued in business until around 1840, with his design being used uncredited by many other makers, such as Simms, Barker, Jones, and Troughton after the patent expired in 1826. No doubt as a result of this, Schmalcalder fell on hard times, dying in poverty in 1843 and being buried in the Strand Union Workhouse cemetery. All Schmalcalder patent compasses have a serial number in the lid and on the base, with the ones from 82 The Strand having a letter’B’ as the prefix, and the ones from 399 The Strand having a letter’C’ prefix. (This compass has the serial number 2150, with the’C’ prefix). In very good, original condition, and full working order. The compass finds North very well. The glass, sighting vane, and prism are all in very good condition. There are some minor marks to the compass card. Both the manual brake and transit lock are working well. There is some wear to the original lacquered finish of the brass case. Dimensions: 72mm diameter 90mm inc. I have several other antique compasses listed at the moment. Please check out my other listings. _gsrx_vers_854 GS 7.0.18 (854). The item “SCHMALCALDERS PATENT PRISMATIC COMPASS c. 1826 VERY RARE GEORGIAN ANTIQUE BRASS” is in sale since Friday, July 19, 2019. This item is in the category “Collectables\Scientific Collectables\Scientific Instruments\Other Scientific Instruments”. The seller is “coniston1980″ and is located in Lancashire. This item can be shipped worldwide.
- Type: Scientific Instruments
- Sub-Type: Compasses/ Dividers
- Material: Wood
- Period: 1800 to 1900
- Country/Region of Manufacture: United Kingdom