This month’s measure is a fascinating example of how manufacturers would squeeze extra function into an instrument to attract customers.

Mechanical pedometers had been invented prior to 1770 and this much later instrument answered an early 20th century fad for pedometers. Carried on the person while walking they indicate steps and thereby distance covered. Shaking the pedometer, you can hear the pendulum striking internal stops as it swings. Most mechanical pedometers are of dubious accuracy, particularly over varied terrain, and this would have given only a rough guide to distance paced and little more. This particular instrument also combines two additional features with the pedometer. These are a small compass, and a curvimetre, or map measure.

The primary instrument is the pedometer. This records each step made whilst walking and the first increment on the dial face is for 80 yards covered. The outer dial registers up to 1760 yards/one mile. Upon reaching one mile, the small dial to the right of the dial face will register 1. And so on around this dial to a total of 10 miles before beginning again. Upon reaching 10 miles, the small dial to the left of the dial face will register 10 miles, and so on to a total of 100 miles, before beginning again. There is a reset switch on the side of the pedometer that when pressed down, resets the needles on these three dials. This mechanism has got a little weary in the intervening years since first manufactured and the small left dial needle is reluctant to reset.

The combination measure includes a simple compass at the top. This is situated just below the hanger loop and considerable wear to the nickel coating has occurred as a result of continued abrasion. Unsurprisingly this is not liquid filled or damped and the magnetised needle can waver before settling down. The small compass measures 11mm across its extreme diameter. The interior of the compass has a simple circle of plain card around its inner circumference. It is a press fit into its metal housing. Cardinal and intercardinal points of the compass are included with small secondary intercardinal points also shown. Though small, the compass does indicate magnetic direction, so while perhaps of limited use today, it may have been of more practical use in its time.

The final measure on this little fob style instrument is a map measure. This is very simple measure. The small finely toothed tracking wheel at the base of the case is moved along a line on a map, as it rotates, this moves a needle around the third dial on the instruments face, located beneath the central needle. This indicates inches travelled on a map or drawing. Most simply this would be used with a one inch to one mile scale map, each inch travelled, or tracked, indicates one mile. Though other imperial scales could be extrapolated from this.

Beyond the dial increments, there are almost no markings on the combination measure. There is nothing to indicate the manufacturer or even country of origin. There do appear to be tiny numerals- 20, on the back edge of the fob hanger loop, but these tell us nothing. For more information we have to remove the press fit back of the case.

Removing the steel back of the case shows that there is some useful information stamped on the pendulum. It is this that informs us who the manufacturer was- “DEPOSE HC” with the outline of a curvimetre between the letters HC. This is the trademark of the Henri Chatelain firm of instrument makers. ‘Depose‘ simply means that the design has been registered. I do not know what the letters F.S and R.S. also stamped on the movement mean. I would guess that one is step length and the other possibly the regulator spring, but could be wildly wrong. I welcome anyone telling me.

Despite having left a legacy of beautifully constructed instruments, it is difficult to tie down much information about Henri Chatelain beyond the manufacturer being founded in the late 1870s (variously 1876 or 1878) and based at 10 Rue de Belzunce, Paris, France. Henri Chatelain died 1 June 1921. F. Baudet took over the company from 1921/2, retaining the Chatelain name. The Chatelain/Baudet company was subsequently taken over by Henri Burnat c1940 and the trademark was then altered to HB with a period where both sets of initials were used.

There were various versions of this combination measure. Some lacked the compass, others were metric. The metric version is listed as model 357, the imperial version, measuring miles, is shown in both the Henri Chatelain catalogue of 1907 and the F. Baudet catalogue of 1925 as model 457. Model 257 was a combination map measure and compass, lacking the pedometer.

While the model number 457 remains consistent, there are differences in design. The fly-back reset switch is simpler on our version and the 1907 model shown is very obviously an early design with a knurled surround to the compass. Our combination measure is closer in design to that made by F. Baudet in 1925. Other contemporary advertising reveals that this change in design occurred soon after the 1907 advertisement.

This combination measure would have been retailed by various outlets. One such was Richard Melhuish Ltd., a company established in 1828 and based in Fetter Lane, London. They included this combination measure as one of the pedometers advertised in their 1913 catalogue.

Five models were shown. They list our Map Measure of the Month, model 457, as their model 2026, with four hands registering 80 yards to 100 miles. It was their most expensive combination measure, selling for 14 shillings and sixpence.

It is quite a chunky instrument weighing 65.5g. The case has a diameter of 46mm and the visible dial face beneath its domed crystal is 38mm diameter. There isn’t much to the map measuring mechanism but it still lacks accuracy. Tracking 24 inches on a map indicates 25 inches travelled on the dial.

Three Points of the Compass has looked at a few more Map Measurers in detail, including some other measures also made by Henri Chatelain. Links to these can be found here.