A Francis Barker Mk V Service Pattern Clinometer, dating from c.1939. The clinometer was made by F. Barker & Son and is marked in gilt lettering on the case 'F.B&S (1932) Ltd’, along with the British army 'broad arrow' mark, and the serial number 'B439'. The leather case is also stamped with the broad arrow mark, showing that the clinometer was produced for military use.
The clinometer is in mint, unissued condition, full working order and comes complete with its original leather case and cardboard box. The instrument is housed in a blackened brass case, with a glass window to illuminate the degree markings on a scale attached to a swinging metal hoop, pivoted in the centre. Elevation readings are shown by red figures, depression by black figures. The scale is viewed though a pin-hole sight in the edge of the case. The image of the scale and index line are reflected in a small magnifying mirror, while at the same time the objective is seen through a small square window opposite the pin-hole sight.
The prismatic clinometer was invented by W. F. Stanley c.1860, while the mirror clinometer was patented by Major Watkins in 1884. Several different models were made by a variety of scientific instrument makers over the next 50 years, with the only significant differences being the size and shape of the illuminating window. The earliest versions had a large window covering half of the surface area of the case, others had a small circular window, and most adopted the shape and size of window that was used by Barker in the Mk V.
Francis Barker & Son: were established in London in 1848, as a maker of compasses and scientific instruments. Acknowledged as one of the finest scientific instrument makers of the 19th century, Francis Barker produced a wide range of iconic compass designs over the years, supplying major retailers such as Negretti & Zambra, J. Lizars, C. W. Dixey, Dollond, and many others. The company prospered until 1932, when it was taken over and became F. Barker & Son (1932). After WW2 the company changed hands several times and the name is now owned by Pyser Optics of Edenbridge in Kent. They continue to produce the renowned Barker M-73, widely acknowledged to be the world's finest prismatic compass.
Condition:
The clinometer is in mint, unissued condition, and perfect working order. There is just a little dust under the glass window. The fitted leather case is in as-new condition, unused, and complete with its shoulder strap and original cardboard box.
Dimensions: 70mm diameter (leather case: 80mm)
