A rare example of a 'HC' (Henri Chatelain) twin dial map measurer, retailed by Alexander of Manchester. 29mm in diameter, this is a well made instrument for measuring lengths or distances on maps (Francis Barker made similar instruments to these at around the same time, their version was known as 'The Rotameter'). The main dial is calibrated in inches and reads from zero to 48 inches. The subsidiary dial is calibrated in 'Lines' and reads from zero to 16. It has a black handle, which is screw threaded and removable. Although probably mainly intended for use with maps, this instrument can also be used to measure distances on any flat surface. Dating from the late 19th or early 20th century, this instrument was made in France and is marked on the back of the case: 'Made in France, Depose HC'. It is also signed by the retailer, Alexander of Manchester.
Condition:
In very good condition and full working order.
Dimensions: 50mm (main dial: 29mm diameter), length including handle: 115mm
