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Map measure of the month: George Philip & Son Rotameter

Philip & Sons Rotameter, in the hand
Philip & Sons Rotameter, in the hand

“a small, but sturdily built, wheeled measurer, fitted with a dial and rotating hands which indicate lengths of traverse up to 25 feet or 300 inches”

Philip & Son
Rotameter

Cartographic publisher George Philip & Son, (founded 1834), opened a sales outlet in 1851-2 for their geographical and educational publications at 32 Fleet Street. Numbers 30 and 31 were added at some point after 1940. The Fleet Street premises had been previously owned by the publisher John Murray. In 1947 London mapmaker Stanfords sold their company to cartographic publisher George Philip & Son. I am unsure when Philip & Son vacated their Fleet Street address, certainly they were still operating out of there in 1960 and had vacated the premises by 1979.

George Philip and Son remained a family firm until 1987 when it was sold to the Octopus Publishing Co, part of the Reed International Group of Companies, from when it then traded as George Philip Ltd. Stanfords split from the George Philip Group in 2001. The Rotameter was not the only map measure sold under the Philip & Son name; Three Points of the Compass has previously looked at their Universal Simplex.

The German made Rotameter Map Measurer sold by Philip & Son repeats the name of a much earlier British made map measure from Francis Barker & Son. That Victorian measure was looked at in a previous post. Both Rotameter measures are of a particularly small design that would sit in a small pocket or could be hung from a watch chain. There is insufficient information on the measure to determine from which German manufacturer it originated. Following a ruling by the Federal Court of Justice in 1973, “Made in Germany” was used to signify most items manufactured in western Germany while “Made in GDR” was used for those items manufactured in eastern Germany. This informs us that this little measure probably predates 1973, that date reinforced by the information on the card box for it that could, of course, have been made and printed at a different time.

Rotameter, front
Rotameter, front
Rotameter, rear
Rotameter, rear

The rotameter has the appearance of a late 20th century manufacture, but it is a little difficult to establish exactly when the Rotameter map measure was manufactured in Germany or sold by Philips in the UK as there are few clues. The cost is shown on the box. Thirty shillings is a pre-decimal value so at the very least we can say the box pre-dates when the UK converted to decimal- 15 February 1971. It is worth noting that thirty shillings was not an insignificant cost. The seller’s address is also shown as 30-32 Fleet Street, London. A premises it is known that Philips & Son occupied from 1851 until some point after 1960, though vacated prior to 1979.

The card box is simple, measuring 67mm x 46mm x 16mm when closed. Both bottom and lid have stapled corners and there is a paper descriptor pasted to the lid. There are no further markings. While the paper pasted to the top of the card box shows this to be an instrument sold by Philip and Sons, the measure would have additionally been retailed by others.

Rotameter, in box
Rotameter, in box
Card box with paper face
Card box with paper face

The Rotameter has a polished steel case and domed crystal face. There is little information on the measure. The only words are ‘INCHES’, ‘FEET’ and country of origin- ‘GERMANY’, shown at the bottom of the paper dial. The measure weighs 36g and measure 27mm x 60mm and 7.8mm thick to the extreme point on the crystal. It is a simple measure with just the front dial face and a plain back. There are two blued needle hands, each corroding very slightly. The long needle is measured on the outer concentric dial, tracking inches in inch increments, to a maximum of 12 inches. 12 inches equals one foot. A smaller second needle records these. It tracks round the inner dial, measuring each complete rotation of the long needle, to a maximum of 25 feet. This has an external diameter of 16.7mm. There is a quite large tracking wheel at the bottom that is moved along a line on a map, plan or drawing. A small steel needle at the bottom aids visual tracking of the quite difficult to see increments on the tracking wheel. There are no fine teeth or knurling on the edge of the tracking wheel, yet the smooth mechanism and large diameter of the wheel enables it to move smoothly on paper with no slipping or skidding. The Rotameter is a ‘watch-type’ measure with small steel ring on a hanger at the top of the case. Another example in my collection shows that the hanger at least has been changed to or from a knurled type at some time. One of the dial needles has also changed in design. Finally, the word ‘GERMANY’ has changed in size, but other than those, all other features appear to remain the same.

Two Rotameters show an evolution in the case hanger
Two Rotameters show an evolution in the case hanger

The Rotameter has a slip of paper accompanying it, measuring 202mm x 76mm, folded into the box. This is not the simplest set of instructions to understand, and the near obsolete units of measure would confound most modern users. The Rotameter is primarily intended for use with one inch to one mile scale maps. The instrument dial measures in inches therefore each inch is equal to one mile. Each inch on the dial is divided into eight, therefore eighths of a mile. An eighth of a mile being a Furlong. A Furlong is 220 yards.

Rotameter instructions
Rotameter instructions
Rotameter dial face
Rotameter dial face

The tracking wheel at the base of the instrument also has further divisions around its circumference. Each division equates to 55 measured yards. 55 yards is equal to 10 Poles. A Pole (also equivalent to a Rod or Perch) is an old unit of measurement for length or area. As a unit of length, a Pole is equal to 16.5 feet (16 feet six inches). So, one division on the tracking wheel also equals 165 feet.

Tracking wheel shows divisions of 55 yards 10 poles
Tracking wheel shows divisions of 165 feet

So, by use of multiplication or division, the measure is also suited for use with 1/4 inch to the mile, 1/2 inch to the mile, two inch to the mile, ten inch to mile etc. scale maps. The tracking wheel has markings for 0-8, 8-0, 0-8, 8-0 as it rotates around one full revolution. The Rotameter measures accurately. It is simple to use and tracks smoothly with no discernible resistance from internal gearing.

Rotameter, box and instructions
Rotameter, box and instructions

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

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