Tag Archives: meilograph

Opisometer in case stamped Edward Stanford Charing Cross

Map measurer of the month- Stanford’s opisometer


Bone handled opisometer with finely turned finial

Bone handled opisometer with finely turned finial

An opisometer is a curious instrument. As soon as you handle one it is pretty obvious how it works. A handle, in this case made of bone, probably from a cow, with a small milled wheel that turns easily on a supported fine thread. There is also a small metal pointer to aid in locating whatever it is you are measuring.

An opisometer is easy to use with irregular lines on a map or drawing

An opisometer is easy to use with irregular lines on a map or drawing

What is essential is a scale to read off against once a line has been precisely tracked. You wind the wheel to one end of the thread, then wheel it along a line on a map, or along any distance you are measuring, then turn the wheel backwards against a known scale. With maps, the scale usually appears at the bottom. Simple to use and effective. Opisometers are still made today but seldom for use with maps, more as an aid in the medical or surveying worlds.

Stanfords Opisometer in small leather carry case

Stanfords opisometer in small leather carry case

Opisometer advertised in a 'Dictionary of British Scientific Instruments', by the British Optical Instrument Manufacturers' Association. 1921

Opisometer advertised in a ‘Dictionary of British Scientific Instruments’, by the British Optical Instrument Manufacturers’ Association. 1921

Having first stated as an employee of Trelawney Saunders at 26-27 Cockspur Street, Charing Cross, London in 1848, Edward Stanford became a partner in 1852. This business relationship never lasted the year however and Stanford became sole proprietor in 1853, expanding his shop, that sold maps and charts, to 7-8 Charing Cross. The business further expanded and a printing works in nearby Trinity Place was purchased. Stanfords became the map maker and seller in London. Now situated at 7 Mercer Walk, Covent Garden, they still enjoy an enviable reputation to this day supplying maps for countless expeditions across the globe.

As well as maps and charts, Stanfords sold many accessories including map measurers. The opisometer shown here is unlikely to have actually been made by Stanfords. It was likely supplied to them by a manufacturer of fine mathematical or surveying instruments. It is difficult to date, certainly they were being sold in the 1870s and the example shown probably dates from around then, but examples were still available for purchase for much of the first half of the twentieth century. Though an all metal construction became more in favour at the turn of the century.

The opisometer is pretty generic in design. Other sellers of surveying and mathematical equipment would also have stocked these, each seller having their own address stamped onto the bespoke leather case that held these quite delicate instruments. The Stanford example is quite small when compared against others that were available. It measures just 97mm (3 13/16″) in length. The turned and pointed finial on the end of the bone handle shows that this is an English made instrument as each country had their own particular design. It will measure a line 958mm (37 3/4″), so over a yard/almost a metre, which is quite remarkable for such a small instrument.

Small Stanfords opisometer (top) with larger opisometer supplied by Elliott Brothers who were making these instruments in the late nineteenth century

Small Stanford’s opisometer (top) with larger similar opisometer supplied by Elliott Brothers who were making these instruments in the late nineteenth century. The bottom example dates between 1853-1873


My much used German made map measurer

Map measurers

Map measurer, opisometer, curvimetre, mile-o-graph, meilograph, chartometer, call them what you will, in the era of digital mapping, who uses such an antique analogue object today? Well, Three Points of the Compass still does. I have used a simple little map measure for decades. The  cheaply made one shown above, made in Western Germany,  has been pulled down off the bookshelf hundreds of times over the past twenty years when planning routes. It replaced another that gave equally lengthy service but had eventually died the death.

It never goes on actual walks with me. Though I am one of a seemingly dying breed who still likes, appreciates and takes hard copy maps with me on trail. If I want to measure a distance on the map while sitting in a tent, pub or hostel lounge, I either guesstimate, infrequently use a roamer scale on my compass baseplate, a strip of paper which is then measured against the scale at the bottom of my map, or, most frequently, I use a length of thin cordage. The small hank of 2mm yellow cord in the image below is one of the two I carry for attaching my Katabatic Palisade quilt to my sleeping pad.

Assortment of map measurers from Three Points of the Compasses collection. Some cheap and nasty, some peculiar, one or two beautiful and uncommon

Assortment of map measurers from my collection. Some cheap and nasty, some peculiar, one or two beautifully made and uncommon

Plastic map measures sold to readers of a popular motoring magazine

Plastic map measures sold to readers of a popular motoring magazine

Map measurers can be sweet little pocket watch style affairs that were tucked into the waistcoats of the gentry, or simple little wheeled opisometers, like the one below,  sold in the likes of Stanfords map shop in the mid-twentieth century.

They could be made of plastic, bakelite or metal. Have handles incorporating bone or ivory. Cheap versions were given away at petrol stations, or combined into all-singing all-dancing measurer/compass/thermometers made in China by the thousand. That said, they still work. The cheapest will do the same job as the most expensive gold plated measurer ever made. They even make incredibly expensive digital versions today. I look on them with dismay, much preferring my little analogue measurers.

Simple opisometer

Simple opisometer

Newspaper advertisement for Morris's 'Wealemefna', a 'new design of map measurer'

Newspaper advertisement for Morris’s ‘Wealemefna’, a ‘bijou’ map measurer. The Graphic, 1880

The idea of map measurers is an old one, probably as old as ‘to scale’ maps themselves. Beyond simple calipers, early map measurers, or opisometers were very simple affairs indeed, little wheels on a threaded bar that could be pushed along a line. More expensive designs that incorporated a dial scale didn’t really appear in any great numbers until the later nineteenth century.

Anyone that required a map was also using a map measurer. The military use them, sailors use them, motorists use them, town planners and draughtsmen use them, and still, just a few walkers use them. You run a little wheel along a route, a path, a road, a river, a line on a drawing, then either read off the result or measure against a standard.


Box for 'Self-Registering Rotameter', giving detail on how to use

Box for ‘Self-Registering Rotameter’, provides detail on scale and how to use

While a piece of cord or length of paper will simply measure a length, more complicated versions can measure in many units- multiples or sub-units of inches or feet, centimetres or metres, versts, miles or kilometres. Also to different scales- The two-faced French made measurer below has scales for 1:20 000, 1:25 000, 1:40 000, 1:50 000, 1:75 000, 1:80 000, 1:100 000 and 1:200 000. Made almost a century ago, it is still an effective and useful piece of kit that cost me less than a tenner. Not that I ever use it of course, I still pull down the old favourite from the bookshelf.

Map measurer by Henri Chatelain, with Quarter-Inch Ordnance Survey map to The Border, 1935

Map measurer by Henri Chatelain, with “Quarter-Inch” Ordnance Survey map to The Border, 1935

Along with thousands of other hikers I rely very much on my online O.S. Maps when planning my routes. This will give me not only distance but also daily elevation. However I still like to use a map measurer on my paper maps when I can. It forces me to look at the terrain, the twists and turns, the type of country being crossed- across bogs, through woods, traversing moorland, traipsing through the backstreets of towns.

I won’t go in to any great detail on map measurers here. There is an expanding page on my website that gives more information. Over the years I seem to have built a bit of a collection of these little devices, just a small handful of which are shown above. There seems to be a dearth of information on these online or in print form. Perhaps it is because they aren’t that interesting, just to the likes of me and one or two other like-minded souls. So I have decided to share just a few from my collection with you- good reader, over the next year. Twelve, one a month, beginning January. I bet you cannot wait…

The ditty bag/repair kit that Three Points of the Compass carried on the Cape Wrath Trail in 2018. A Leatherman keychain multi-tool formed a vital component of this

The ditty bag/repair kit that Three Points of the Compass carried on the Cape Wrath Trail in 2018. The hank of 2mm cord was often pulled into use as a simple map measurer when considering alternative routes due to weather or resupply necessity.