Found in a loft

A recent visitor to UKMA’s web site has made contact with us explaining that, when clearing out a loft, she had discovered what appeared to be proposals for a “Think metric” campaign aimed at the general public. She says, “It would be interesting to know if they were used or not and where”.

The proposals, which appear to have been prepared in the late 1960s, comprise seven sheets. They were devised by David Collins, designed by Crosby Fletcher Forbes and printed by Mears Caldwell Hacker, Letterpress & Lithography, of Clapham Road, London SW9.

One sheet introduces the series with the “Think metric” slogan – used around that time by the Construction Industry Training Board for its successful metric education programme.

Think metric

The text that accompanies the sheets describes their purpose as follows:

“The sheets … are intended to help you familiarise yourself with the metric dimensions of the objects around you and the distances you are likely to travel on foot or in a vehicle.

“Sheet 1 Rule of thumb. The universal method of measurement is by matching, spanning or pacing dimensions with the hand, foot or limb. The hand span (20 cm) and the thumbnail (15 mm) are common units of measurement on the Continent. These dimensions are necessarily approximate. People vary in size. Noah’s ‘cubit’ (the length of the forearm) may have been anything between 18 and 22 inches. The sizes on the sheet are those of a six foot man of normal proportions.

“Sheet 2  Common objects. The smallest dimension that the eye can differentiate is 1/64 inch or approximately half a millimetre. This is half the thickness of a book match. The examples shown range from a book match to a milk bottle.

“Sheet 3  Indoor environment. The size variations illustrated range from a 3 inch tile to the length of a bed, but the objects are still of a size that we can manipulate ourselves.

Sheet 3

“Sheet 4  Outdoor environment. Once out on the street, entering a public building like a cathedral or the British Museum, the human body shrinks, and can only be used for measuring the puniest details. Sizes of buildings, heights of trees and measurements of street furniture cannot be expressed in the same terms as the furniture in our homes.

Sheet 4

“Sheet 5  Walking distances. How many times in the course of a lifetime are we stopped in the street by a stranger and asked the whereabouts of a building or monument? ‘Is it walking distance?’ ‘About half a mile. See the turning about a hundred yards down on the left? Well …’ The phrases flow easily now but shortly we must be prepared to say as readily ‘About a kilometre … 100 metres down on the left …’.

“Sheet 6  Driving distances. Our conception of long distances is probably limited to one or two well travelled routes between towns. Your centre is no doubt on the map shown on the sheet. The distances between main centres, and from them to their surrounding landmarks, are measured by the shortest practicable route along classified roads. The map is diagrammatic (not to scale) in order to show the towns clearly without overlapping. “

Sheet 6

Readers may disagree with some this. Attitudes have moved on in the last 50 years. But the proposals illustrate how little the UK has moved on in matters of measurement in that time.  Such a public information campaign is needed now just as much as it was when these proposals were prepared, in contrast to many other countries around the world that made a successful metric transition in the last century, such as Australia, China, Japan, New Zealand and South Africa.

Metric views apologises for the poor quality of some of the sheets. These are the best that could be achieved in the circumstances.

So, do any readers remember seeing this any of these sheets or noticing a campaign linked to them?

In conclusion, UKMA would like to thank the person who drew to its attention this interesting discovery.

4 thoughts on “Found in a loft”

  1. I was in South Africa at the time. I recall seeing large posters in South Africa (in 6 languages) explaining the conversion from pounds, shillings and pence to rands and cents along with a ditty “I am Dan Dan the Rand-cent man, I will give cents for pennies whenever I can …”. However I never saw similar posters in connection with the metrication. I do recall once incident – one Sunday afternoon I was at my girlfriend’s and her mother asked us to go down to the corner shop and get some milk. She said – “now lets see if I can get this right – will you please get two litres of milk”. I thought this rather a lot for a Sunday afternoon, so I asked her “Mrs Plantema, how many big bottles [one litre] of milk and how many little bottles [500 ml] of milk do you want”. She replied “one little bottle”.

    The technique that the South Africans used was to throw people in at the deep end, but to protect them by using strict price control. Also, it became unlawful for any retailer to sell measuring equipment that was calibrated in imperial units. If seems that the South African Government had heard the maxim “That which I hear, I will forget, that which I see, I will remember and that which I do, I will understand”. Has the British Government heard the saying?

    Liked by 1 person

  2. If these proposals were all about “Thinking in Metric”, then why does this article describe them in FFU?
    “People vary in size. Noah’s ‘cubit’ (the length of the forearm) may have been anything between 18 and 22 inches. The sizes on the sheet are those of a six foot man of normal proportions.”
    Shouldn’t this have said that the cubit was about 500 mm +/- 50 mm and the sizes on the sheet were for a 180 cm man?
    “Sheet 2 Common objects. The smallest dimension that the eye can differentiate is 1/64 inch or approximately half a millimetre.”
    This statement makes it seem that the human eye can differentiate exactly 1/64 inch and the 0.5 mm is just an approximation. 1/64 inch is 0.4 mm. This article doesn’t agree:
    “Your naked eye can see objects of any size, if they emit or scatter enough light to trigger its detector cells. Light visible from the star Deneb covers a minuscule fraction of your visual field (its ‘angular diameter’ is 0.0024 arcseconds). A light-emitting object seen as the same size when 15cm from your face, would be 1.75 nanometres wide. That’s only about 10 times the width of an atom of gold! And you can ‘see’ smoke and fog, even when their constituent particles are too small to pick out.”
    “What is limited is the eye’s resolution: how close two objects can become before they blur into one. At absolute best, humans can resolve two lines about 0.01 degrees apart: a 0.026mm gap, 15cm from your face. In practice, objects 0.04mm wide (the width of a fine human hair) are just distinguishable by good eyes, objects 0.02mm wide are not.”
    “The size variations illustrated range from a 3 inch tile….”
    Would that be a 75 mm tile or maybe it is 80 mm?
    Kind of hard to think metric if metric doesn’t appear anywhere.


  3. I don’t recall such a document being published, and as some critics have pointed out it is far from perfect.
    The Metrication Board of the 1970s did take advertising space in newspapers, supposedly to promote the idea of the metric system to the general public. Such adverts were usually little more than rhyming couplets intended to explain metric units in terms of familiar imperial. Hardly educational and hardly encouraging thinking in metric. When the Metrication Board was wound up I did not see it as a big loss because to my mind it was ineffective, though it may have provided to industry some support that I was not aware of. One useful item I did get from it was a leaflet describing ISO Metric screw sizes and the across-flat dimensions of the corresponding nuts. I have retained this in my workshop file to this day.


  4. @Daniel – The wavelength of light varies from 400 nm (violet) to 700 nm (red). According to wave theory, if you “see” anything, the object which is reflecting (or generating) has to be an order of magnitude larger than the wavelength of light involved otherwise the fringes caused by the edge of the object will mask out the detail of the object. This does not take into account the optics associated with the eye itself. (A microscope can take into account the effects of the eye’s optics but you need an electron microscope to take into account the limitations associated with the wavelength of light. Thus, using an optical microscope, you should be able to see details down to about 0.01 mm.
    What the article that you read failed to mention is that when you are looking at a distant object, it is not the size of the object that matters but the number of photons in the correct part of the electromagnetic spectrum – you will not be able to see any detail, just a “blur” of light.


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