“The new Simplex Curvimeter or wheel map-measurer is indispensible to Officers, Engineers, Motorists, Cyclists, Hikers- indeed to all who use maps and plans. With it distances can be quickly and accurately calculated, measurements made, and outlines traced. The instrument is strongly made, convenient in size, and easily handled“

An opisometer is a simple instrument to use and there are few parts to go wrong. While opisometers are not complicated instruments, they do require care in their manufacture, which is little more than a handle supporting a small milled wheel turning easily on a fine thread screw. They may also feature a small metal pointer to aid in locating whatever it is being measured. There can be few map measurers as simple as Philips’ Universal Simplex.

Cartographers and other outlets have been selling opisometers for decades. Three Points of the Compass has looked previously at a lovely bone handled example available from Stanfords in the 19th century. That would have been quite an expensive item to purchase and no doubt sales were limited. Philips’ Universal Map Measurer sold for three shillings, putting this accurate measuring device within the financial reach of many and no doubt thousands were sold.

The measure is very small. 41mm in length and 24mm across it’s width. It weighs just 6 grams. Living up to it’s advertising hype, it is genuinely small enough to be slipped into the pocket of the target audience of Military Officers, engineers, motorists, cyclists and hikers. The threaded spindle on which the knurled tracking wheel moves is 1.60mm in diameter and has a very fine thread. The fine thread means that the tracking wheel can be moved laterally along a spindle measuring only 20mm yet it will still track a line up to 1550mm, over a metre and a half.

The handle is Nickel Silver. This silvery alloy contains no actual silver, being formed from copper, nickel and zinc. Being so small in the hand, the opisometer is a little slippery and difficult to grip between finger and thumb so a small knurled section on the handle assists with this. The threaded spindle is steel and the tracking “cogged” wheel moving laterally along its length is finely milled to provide grip on a map surface and help prevent skidding. A small pointer is included on the support frame. This frame also carries thirteen notches on one side that may aid the user in indicating a distance travelled, but it would require some experience to ascertain this. An accurate measurement is obtained by rolling the wheel back on itself across the scale included at the base of most maps.

The measure was undoubtably knocked up in one or more small engineering factories to quite exact specfications. Despite a design brief, small, subtle but mostly unimportant differences can be found in the construction. A thicker frame material here, a slightly thicker tracking wheel there. Most of these differences are probably simply down to availabilty of materials or tools at the time.

There are two very different models of the Universal Simplex. One being much smaller than the other. This represents a defined step-change in design. If one measure is small, the other is tiny. It is 43mm x 16mm, weighing 5 grams. Despite the modest dimensions, this is a well made measure demonstrating better quality materials that its larger brother. The handle is stainless steel, the spindle support is painted, the threaded spindle 1.5mm diameter and the finely knurled tracking wheel is brass. The threaded spindle is smaller on this measure, just 14m in length. Despite this, a line up to 1170mm long can still be tracked.

Both Simplex measures were sold through Stanfords. A little knowledge of this famous cartographer, map maker and travel book seller explains this relationship. When opened, Stanfords was the only map maker in London. In 1853 they had a shop in Charing Cross and print works at Trinity Place. Considerable expansion followed and Stanfords became an essential destination for explorers such as David Livingstone, John Murray, Robert Falcon Scott and Ranulph Fiennes when obtaining maps of far-flung locations. In 1873 the print works was restablished to 12-14 Long Acre, and the entire business subsequently squeezed in to that premises in January 1901. It was from that location that the Universal Simplex map measure was sold. The business remained in the family until 1947 when John Keith Stanford sold the company to the cartographic publisher George Philip & Son (itself founded in 1834). George Philip & Sons relocated their Liverpool hub to 32 Covent Garden in London from where they sold their geographical and educational products. The instructional leaflet for the Simplex measure shows this address. A hundred and eighteen years later the Long Acre premises closed, Stanfords having relocated to 7 Mercer Walk in Covent Garden in 2018. Stanfords split from the George Philip Group in 2001. It is a little difficult to establish when the Universal Simplex was on sale. Certainly it was being sold in the mid 20th century, probably remaining on sale into the 1970s at least.

Packaging was simple. Both sizes of Universal Simplex measure came in a small card box, containing a printed set of instructions along with the measure. Only the larger Simplex had its name recorded on the exterior of the box- Philips’ Universal Map Measurer.

An unanswered question remains. If the two variants of this little opisometer are both advertised as the ‘New‘ Simplex measure, what of the ‘old‘, or original Simplex? It is possible that such a measure never actually existed. The Universal Simplex can be easily found on the second-hand market today. There is little to break on such a simple measure and they last well, continuing to work perfectly fine into their old-age.

Three Points of the Compass has looked at a few more Map Measurers in detail. Links to these can be found here.

The map that appears in the images above is a double-sided Map of London, drawn and printed by George Philip & Son, 1953. Edward Stanford Ltd. There is some more information on this particular map here.