Troughton and Simms Theodolite Mk 3
This theodolite is in untouched condition. It has hardly been used - there are no wear marks at all on any part of the instrument. There is a military broad arrow stamped on the standard.......
In addition the instrument is also stamped with " No 52 1900" which I would think was labelled by the military as I have never seen markings like this on any other T & S theodolite.
Several of the attachments also are numbered - Trough Compass #50, Extension Eye Piece #206, Base #75.
The original purchaser had the option of either four foot screws or with three screws and locking plate. This instrument has the latter.
Accessories include sun filters, an extended eye piece for erect image, trough compass, key, additional cross hair insert and diagonal eye piece.
There is also a "direct spring arrangement" for the horizontal tangent screw which is different to the opposing spring arrangement in the other T & S theodolites in that era. The attached photo shows three of my T & S theodolites together to show various differences. Note things as simple as different knurling on the thumb screws.
It is also interesting to note that the included key locks both boxes. The combined weight is 12.9 kgs
One of the boxes is also marked with " 147 Coy RE". ( Royal Engineers 147 Company ????)
Also shown in the slideshow is a copy of part of the 1897 Troughton and Simms Catalogue showing the theodolite and price list at the time. ( Courtesy of the Smithsonian Library Item 51626)