Measures used in different trades

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Old British Paper and Book sizes

FromThe Universal Encyclopedia, in twelve volumes, edited by J.A. Hammerton and published by The Educational Book Co. Ltd., Tallis House, Whitefriars, dated around 1929.
"Sizes of paper. Term for the dimensions of printing, writing, drawing, and brown papers. Of British printing paper there are 14 sizes, ranging from foolscap 17 ins. by 13 1/2 ins., to double post, 32 ins. by 40ins; of writing and drawing papers, 17 sizes, varying from pott, 15 ins. by 12 1/2 ins., to emperor, 72 ins. by 48 ins.; and of brown papers, eight sizes, which range from Kent cap, 21 ins. by 18 ins., to casing, 46 ins. by 36 ins."
This adds a further confusion, of different categories of paper! Unfortunately, the article only gives the maximum and minimum sizes in the different categories. I presume that 'brown paper' refers to the strong brown paper used to wrap parcels.

British Envelopes

A correspondent points out that until the size system we have today came in in the late 1960's it seems as though manufacturers had a free rein. He found a reference to postal letters being no smaller than 4" x 2¾", presumably they might otherwise get lost.

He quotes from The John Dickinson Lion Brand envelope catalogue for March 1961:

The 3 1/4" x 6" envelope seems to have been made in a large range of papers and colours.

British newspaper sizes

The sizes are the page as you see it, but of course the newspapers are made of folded paper, so a complete double page is twice that size.

ISO paper sizes

As well as the ISO 'A' paper sizes, there are 'B' and 'C' sizes as well. They have the same proportions but a different starting point.
The B series has been introduced to cover a wider range of paper sizes. The width and height of a Bn format are the geometric mean between those of the An and the next larger A(n-1) format. For instance, B1 is the geometric mean between A1 and A0, that means the same magnification factor that scales A1 to B1 also scales B1 to A0. B0 is 1414mm by 1000mm.
The C series has been defined for envelopes. They are the geometric mean between the A and B series formats with the same number. C0 is 1297mm by 917mm.
For example, an (unfolded) A4 size letter fits nicely into a C4 envelope, which in turn fits as nicely into a B4 envelope. If you fold this letter once to A5 format, then it will fit nicely into a C5 envelope. How nice!
See International standard paper sizes.

The RA and SRA paper series are untrimmed raw paper. RA stands for 'raw format A' and SRA stands for 'supplementary raw format A'. The RA and SRA formats are slightly larger than the corresponding A series formats. These paper sheets will after printing and binding be cut to match the A format. A0 has an area of 1.00 m², RA0 format has an area of 1.05 m² and SRA0 format has an area of 1.15 m². These oversized paper sizes are used by printers.

American paper sizes

Perhaps strictly speaking these should be with the rest of the American units but they seem to belong here. I'm not sure how resistant Americans are to the lure of ISO paper size. Perhaps they've never heard of them! I warn you, if you visit Britain or Europe, everyone will expect you to know what A4 means.

See History of American paper sizes. Ledger seems to be double Letter and Broadsheet is double that again.

This website on 19C USA paper sizes shows that Americans used to have similar names to the old British paper sizes, but with slightly different sizes.

A comment from a correspondent interested in origami:
"If you remove a square from A4, you are left with what has been called the "Left-over Rectangle" which has peculiar properties of its own. This is a very close to the proportion of 7 x 3, though larger than a modern dollar bill. The Americans do a lot of origami folding from this size, although they mostly use their Letter size. The Japanese standards use a different method of calculating the B sizes so that Japanese B sizes are not quite the same as the International ones. ISO B5 is 176 mm X 250 mm, whereas Japanese B5 is 182 mm X 257 mm. So careful if you use Japanese Origami books!

Chinese paper sizes

A Chinese correspondent gave me the following information:

Our Chinese always call book sizes only by number for short. We use a combination of ISO sizes and our own standards. :-)
Fractions are 'Quankai' (whole size), 'Duikai' (cut-to-halves), '4-Kai' (cut-to-fourth), etc. However, only two or three basic sizes are used (Zhengdu and Dadu mainly), so the name of the basic size is seldom spoken out.
In fact, '16-K' for books (26 cm by 18.5 cm) is different from it for drawing paper (27 cm by 19.5 cm), and neither of them is exactly 1/16 of the basic size (109.2 cm by 78.7 cm, so the '16-K' should be 27.3 cm by 19.7 cm). Even ourselves don't know how this happens. :-)

He added this later:

These are "traditional" sizes, used after adopting modern printing industry but before ISO sizes.
The name of book size was in "base paper + division" style. The "K" in 8K, 16K etc. is the Chinese initial of a word "kai", roughly translates to "being cut". So 16K means 1/16 of some original size. However there are special words for original size and half, as I mentioned years ago, Quankai and Duikai.
Now on the topic of original sizes. We adopted two different kinds of original sizes in general, mysteriously neither are in rounded dimention in either metric or pre-1929 Chinese units. One is Zhengdu, 787mm by 1096 mm (2.46 chi by 3.41 chi), the other is Dadu, 850 mm by 1168 mm (2.66 chi by 3.65 chi). Most books are in Zhengdu 16K (Z16K), Dadu 32K (D32K) and Zhengdu 32K (Z32K). In fact, even right now some printing press like to express A5-sized books as "RA0 32K" or something like this.
The writing paper before 1980s (and still now for lower-quality papers) are trimmed a few millimeters, and the trim is even bigger for books, explaining the discrepancy I mentioned a few years ago.
Dadu paper quickly became obsolete for being too similar to A0, but Zhengdu somehow survives even today.

Which side first?

A correspondent has come up with an interesting point:
"Is there a naming convention when describing the size of a book or magazine? Ie: Is a book, or magazine that is 10" wide and 14" long, a 10x14 or a 14x10 object? Cards and photographs for sure appear to be length first, but paper sizes are width first."
Such a simple question! If you look above, you'll see that in the Old British Paper and Book sizes and ISO paper sizes, I've quoted the depth (biggest size) first and the width second. But in the American paper sizes, there is a mixture. I've collected these sizes from various places and use the same way round that they do.

People who use word processors may be aware of a neat way to describe how a page is printed, portrait and landscape. Portrait paintings (of a single person) tend to be taller than they are wide, and landscapes are wider than they are high. So computer printing software uses these terms to describe orientation, and apparently these terms came originally from printing. This doesn't solve the problem, as it describes merely gives the orientation, not which side should be described first.

One correspondent says:
"With regard to your question about width or depth when referring to the printed page or printed sheet.
It was accepted in the repro and printing industry that the depth was always quoted first, i.e. Crown = 20x15 inches (20 inches deep x 15 inches wide) Double Crown = 30x20 inches (30 inches deep x 20 inches wide) etc., these measurements would have been for portrait sizes. For landscape sizes the smaller measure would have been quoted first i.e. A4 landscape = 210x297mm.
In the case of paper size the depth is still written first i.e. SRA2 = 450x640mm, viewing sheets for sheet fed presses as landscape sheets. The way page sizes were written would confirm whether they were landscape or portrait. This practice does not seem to have been adopted by computer software programmers who from my experience in most of the programmes I use place the width before the depth.
Most of the old conventional practices and definitions from the industry, especially Letterpress blockmaking and type composition, have either been completely lost or are now applied in different ways. Before computing the terms and reference we used in the industry and the traditional way that measurement was applied was understood by all in the industry, leaving less room for error."

Another correspondent:
"I'm a hologram designer by day & when we refer to end product use we always use North/South first, then East West measurement to describe a product."
That means presumably that the depth is given first, then the width.

Another, more technical, answer raising a new point:
"Having spent 45 years in print I was always trained and indeed I have always trained others that the standard way to describe plain paper as 450x640mm refers to standard 'long grain'  paper therefore 640x450mm would be supplied as 'short grain'. Likewise plain A4 is normally cut from SRA2 as 210x297mm, however if cut from SRA1 it would revert to 297x210mm to indicate the grain direction on that material. Grain direction can and does have an effect on some laser printers, so its best to be aware. On bottle labelling it is essential that labels are produced with grain running left to right, if produced head to tail would cause labels to peel off bottles. Grain direction is also important when producing printed cartons as if printed wrong grain will create a tube , rather than a box. These are some of the reasons unprinted material must be properly specified so as to identify whether long or short grain is being supplied.
On all printed matter it is correct to measure the head to tail measurement first followed by the left to right.
      297x210mm = portrait       210x297mm = landscape
The naming problems in print only began in the computer age some 30 years ago when US made graphic arts programs (Adobe Stuff) consistently showed width x depth - which is the American way - NOT the British way. Likewise envelopes should be measured from the open edge down, thus a Wallet is 110x220mm and a pocket is 220x110mm Provided everyone in the UK - graphic artists and print production students are properly educated then it will be easier for all concerned, and much less confusion resulting from wrong naming conventions."
The problem is - which naming conventions are the right ones!

Counting sheets of paper

Paper weight

In metric measure, all paper weight is based on how many grams there are per square meter per single sheet of paper (or G/M²). So, you might see a weight like 250 G/M² or 90 G/M².

The United States of America has a more complicated system. The basis weight of a paper is the designated fixed weight of 500 sheets, measured in pounds, in that paper's basic sheet size. It is important to note that the 'basic sheet size' is not the same for all types of paper.

Caliper refers to the thickness of a sheet of paper expressed in thousandth of an inch. This measurement is taken with a micro meter. Generally, the relation between caliper and basis weight is that the greater the caliper (the thicker the paper), the greater the paper weight.

Since this website is mainly covering British units, I'm not going into any more detail. These website might help!

I don't know what happened in Britain before metrication. If you know, please tell me.
A correspondent replied to this plea:
"I worked for a time in the lab of a carton factory. One of the quality checks we did on incoming supplies was the weight of cardboard. This was recorded as the DC weight, referring to a sheet Double Crown size, i.e. 20"x30" but I don't remember (it was 45 years ago!) whether the weight of one sheet was noted or more than one. (We weighed only one sheet but we may have multiplied the answer. My faint memory is that we had a specially calibrated scale for this measurement)."

Type sizes (font sizes)

In fact, if you print off 72 point letters on a computer, you may find that the letters are less than an inch. On my computer and printer using Word in Times New Roman, 'a' is half an inch, and 'A' is three quarters of an inch. A letter which goes below the line, like 'g' or 'y'is slightly less than three quarters of an inch. So the distance from the top of the tallest letter to the bottom of the deepest letter is still slightly under an inch. On the other hand, the distance from the top of one letter on one line, to the top of the same letter on the line below is definitely more than an inch. All this may vary from one word processor to another, from one computer to another, and from one printer to another. It certainly varies from one type face to another. Some styles of lettering are distinctly shorter than others, even for the same type size. The best way to estimate size is to print out a sample!

A correspondent gives the following explanation of the terms Upper and Lower Case used of letters (where upper case means capital letters):
"A lot of people don't know the origins of Upper Case and Lower Case. Letters were kept in large compartmentalised drawers (cases), and for the common typefaces (where you needed to store a lot of letters) there were separate cases for capitals and small letters. The composer (the guy that made up the print) would place both cases on angled shelves in front of him with the capitals case above and behind the other one. Hence Upper Case and Lower Case. The Upper Case tray had compartments of equal size and was set out alphabetically (except for some reason 2 letters - I think it was 'J' and 'V' were at the end after the 'z') whereas the Lower Case tray was set out with the letters used most nearest to the front, and with larger compartments for letters like 'e' than for 'z'."

The same correspondent has pointed out the following:
"Font sizes were originally based on the size of the block on which the letter was mounted, rather than the size of the actual letter itself. So, a 72pt typeface did not necessarily mean that the letters themselves were exactly one inch tall, but the blocks on which they were mounted were all one inch."

From another correspondent:
"Font or fount is not the correct word to use in this context as it means something different in letterpress printing. If you are talking about computer images, then font means the design of the letter that you see on the screen, but if you are talking about letterpress printing, then font (fount is the UK spelling of the same word) is a quantity of a design, usually expressed in a weight (like an eight pound fount of Goudy Modern roman), or as a distribution of letters (8A 40a Goudy Modern roman) - other letters would be in proportion as per a foundry (typecasters) usual distribution of letters). The word you should be using to express to design is not font, but type. Thus to correct the previous correspondent, it should be Type sizes rather than Font sizes".

From the same correspondent:
"Into the early twentieth century, type compositors, so minded or simply out of a steady job, could work from town to town by presenting themselves at the door of the local printshop to see if there was any work to do. This was sanctioned by the union, and if there was no work then the workers in the shop would have a quick collection if they could not prevail upon the boss to find a little work for the chap to do, and you can guess that such was preferred. Generally if there was no work, the journeyman (from the French for 'daily paid labourer' rather than what you'd expect in the circumstances), could be found some typesetting to do, something that was not needed for some time perhaps, or needed a lot of fiddling corrections. This sort of work was known in the printing trade as "grass", for indeed the man would be grazing for the day, and the boss would pay the sum due and the man thus helped on his way at the end of the working day. Walt Whitman was a compositor and knew his way around a printshop pretty well, setting some of his own books for printing himself. His poetry collection Leaves of Grass says something of Whitman's attitude to the work as well as his intimate connexion to the printing of the volume."

Here is a quote from 'Murder Must Advertise" [1933] by Dorothy Sayers. She worked in an advertising agency and used her expertise in this novel. One of the advertising staff has just described a new headline for an advert over the phone to the printer. The previous headline had started with the letter A. The printer is repeating the mod back to make sure that he's got it right.
"Yes; I'll repeat. First line, Goudy caps, starting level with cap A of present headline, O,V,E,R, hyphen, W,O,R,K, ambersand; second line, same fount, 2 ems to the right, O,V,E,R, hyphen, W,O,R,R,Y, dash. Third line. Start under W, Goudy 24 point upper and lower: lower-case w,a,s,t,e, capital N,e,r,v,e, hyphen, capital P,o,w,e,r, screamer."
'Goudy' is the font (which is called a 'fount' - UK spelling). Ambersand is & and screamer is ! (that symbol is used in Mathematics to mean a factorial, and there it's called 'shriek'). The word 'em' means a space the size of the letter 'm'. There is also an 'en' which is narrower. I recommend those two words to Scrabble players!

Shoe Sizes

Shoe sizes vary from one manufacturer to another. Children always should have their feet properly measured by the shoeshop before buying shoes, as the wrong size shoes could damage their growing feet. So I am not going to give an equivalence table for children, as the information below may well be inaccurate. It all seems to be a very grey area!

In Britain, there is a range of children's shoes starting, theoretically, at zero and going up to 13 1/2. This carries on smoothly to the adult range, so the half size above children's 13 1/2 is adult size 1, and this continues up to adult size 13 and beyond (although bigger sizes are hard to find). The base length, child size zero, is a hand or four inches, and the increase in size (such as from size zero to size one) is a barleycorn or third of an inch. Half sizes exist, especially in children's sizes, but there are less common for adults. Please note that these sizes are based on the 'last' (the foot-shaped template over which the shoe is manufactured), not the foot size.

A correspondent claims that a British size nine boot is very close to being a foot long. That seems about right, since the 'last' size will be smaller than the boot.

American shoe sizes seem very confused. Mens shoe sizes seem to be one more than UK shoe sizes (Wikipeida mischieviously suggests that this is similar to the British habit of numbering their house floors from zero, so you go upstairs to the first floor). There are several women's shoe sizes, but the common one is one and a half sizes more than the equivalent male shoe (and so two and a half more than the British shoe size). Girls and boys shoes are not different, and they seem to be in the same range, roughly, as the male shoe. I suspect that any British person buying American shoes should get their feet measured, or at least try them on.

The Mondopoint shoe-size system (International Standard ISO 9407:1991) is based on the mean foot length and width for which the shoe is suitable, measured in millimetres. A shoe size of 280/110 indicates a mean foot length of 280 millimetres (11 in) and width of 110 millimetres (4.3 in). As Mondopoint also takes the foot width into account, it allows for better fitting than most other systems. It is therefore used by NATO and other military services. It seems a very sensible system, which is perhaps why no-one else seems to use it! Who says that units of measure are sensible?

I've based the equivalence tables above on the Clarks website.
Veganline has an excellent website comparing different shoe systems.

British shoe repairs

A correspondent writes:
"I have worked in the shoe repair trade for 50 years, and the thickness of sole leather is measured in irons. There are 48 irons in 1 inch, and the average thickness of a normal leather sole on a gents shoe is between 8 and 10 iron. This is not a measuring system that is fading into obscurity, like many others, but is very much alive, and is in general use in the shoe manufacture and repair trades. However now that we are 'Europeans', it expected that we operate in millimetres rather than irons, but it is a difficult task to change the ways of an established method , especially with the older generation. This is purely a British measuring system. I am an agent for a German tannery, and 'irons' are totally alien to them."

British clothes sizes

The table below was marked as US men's clothes sizes, but it looks the same as British men's clothes. Please tell me if you disagree. I've always admired men for their ability to buy clothes by collar size alone!

The following is British Standard 3666 : 1982, Size Designation of Women's Wear, taken from Tower Hamlet's Trading Standards. I've tidied up the inch values as they were given as direct conversions from the centimetres. You don't want it accurate to the tenth of an inch, do you? Thought so. But that does explain why size 12 seems smaller than the others. It isn't, but it's just where the centimetre/inch conversion does a jump if you are dealing with whole numbers. Use the centimetres if you're worried about it. As there is no requirement for manufacturers or stores to use the British Standard resulting in a range of size indications for the same size of garment from different sellers, accuracy doesn't seem that important. Manufacturers often adopt 'vanity' sizing, and mark a skirt as size 12 rather than size 14.

The European sizes seem to be measurements in centimetres, but of course you need to know what they're measuring!

The US women's clothes sizes are mostly 2 less than the UK's, so a UK size 10 is a US size 8. But the infamous 'size zero' (American) is UK size 4.

I have mentioned standard 3666 above. Here are some more British clothing standards.

Wool trade

A correspondent writes:
"I worked in the wool trade from 1946-1949 after I left school. I worked in the sorting and blending department away from the noise of the carding and spinning departments. We dealt in the finest lambswool and also cashmere. We had 30 pounds to a tod and 8 tods made a pack. I spent my last year with the firm in the blending section so did a lot of weighing."

Elsewhere, I have heard of a tod being 28 lbs, or 2 stone.

Bricklayer

A correspondent writes:
"I spent much of my life as a bricklayer, and struggled through the transformation from Imperial measures to metric. What a fiasco! Try repairing a wall made with bricks measuring 9 x 4 1/4 x 3 inches with bricks measuring 225 x 100 x 75 millimetres - you'd soon see what I mean. (In fact, both sets of measurements actually refer to a brick and a single mortar-joint - 1 horizontal (or bed) and 1 vertical (or perp [perpendicular]). Thus the sensible 'four to a foot' rule governing height (courses) became the somewhat absurd four to 900mm rule, and I might add that brickwork took an abrupt dive in quality from that point onwards.
One archaic measurement that still clung on was in what is known as 'gauged' brickwork. The term refers to the very thin 'perp' joints seen in Victorian and Edwardian arches (and earlier) - esp. those 'flat arches' so prevalent in older houses. I was lucky enough to build quite a few in my career, and they were a fascinating challenge! The bonding agent was a liquid lime-putty, and the joint was very thin. In fact, I don't recall a numerical value for it because it was always referred to as a 'sixpenny joint'; that is, the thickness of a sixpence edge-on. We all used to carry a few 'tanners' to use as a gauge when laying or (more crucially) setting out this kind of work. The arch was made using 'soft' bricks called 'rubbers' that were cut into the characteristic, wedge-shaped voussoirs using a frame saw with a blade of twisted wire. Once cut, the bricks were rubbed to size on a piece of granite paving stone and then 'joggled' with a comb-hammer - which means that a recess was cut in the back of the brick, resembling an open-ended 'frog' which extended almost as far as the underside face or intrados. Once the arch had been carried over the opening, the resulting cavities (visible at the top, or extrados) were filled with the lime putty, thus bonding each brick into the whole. It's interesting to note that the jack arch was never laid entirely horizontal. This is simply because a totally flat arch of this type will actually appear to be slumping, due to an optical illusion. Thus - and this brings us back neatly to your subject - we used to 'spring a lath' across the temporary support used in construction, and the rise at the centre was equal to the thickness of a lath. i.e. one quarter of an inch. (Picture a strip of wood cut to fit tight between the uprights, causing it to bow upwards, with another short strip used to measure the bow in the centre.) It was all done by 'rule of thumb', ha ha ha!"

Metrication in the UK building trade

In the following " means inch, ' means foot, lb means pound, oz means ounce. The other units are linked directly

A correspondent writes:
"Metrication in the UK is discussed in this website, and this was close to my heart as a quantity surveyor in the building industry, where we went metric as long ago as 1970. Fortunately for us builders this wasn't hard to grasp - 4" and 6" pipes were changed to 100 and 150mm; 3", 4", 6" and 9" concrete blocks were readily changed to 75, 100, 150 and 225mm; the tonne was near enough a ton to be understandable; likewise the cwt bag of cement became 50kg, again near enough to be understandable. And your bit of 4" by 2" timber was easily understandable as 100 x 50mm. The metre was a bit of a stretch to match it to a yard, but kerbstones that were a yard long are now made as 900mm.
One thing that has never changed is door sizes. Doors were always 2'3", 2'6" and 2'9" wide, and mostly 6'6" high (some older external doors are 6'8", but this is related to old, bigger brick sizes - another story!), but these sizes have been retained albeit expressed in millimetres. The alternative would have been for manufacturers to continue to make the old sizes for refurbishment projects, whilst also producing the same doors in a range of metric sizes.
One other exception - lead sheet was always described as the weight per square foot, i.e. 3lb lead, 4 lb lead and so on. To give an easily understandable conversion, this was changed to Code 3 and Code 4 lead and so on. No doubt there is a metric way of describing different weights/thicknesses of lead, but unlike the examples I gave above, it would not have been easily related to the well known imperial descriptions.
Having said that, glaziers managed the easy transformation of glass being given in weights per square foot - 24 oz, and 32 oz being the basic ones were, with perhaps a slight change in their actual thickness, changed to 3mm and 4mm.
One final point though - unlike the retail trade and teaching in schools, the building industry doesn't use the centimetre. Measurements are given either in millimetres or metres; there is a fair bit of flexibility in what is used, a room could be dimensioned as 4185 or 4.185 and it's obvious from what it is describing whether the dimension is millimetres or metres. But there would be a fair bit of confusion if the centimetre (or indeed the decimetre - does anyone use that?) were used as well."

English agricultural units

A correspondent writes:
In Shropshire, certainly 1940s & 1950s. the weight of a pig was measured in score ( 20lbs).
On the Somerset Levels in the 1960s the following were used for contracts for land drainage activities;
     Dredging the ditches measured in chains (Gunter's)
     Weedcutting (both in the stream and on the bank) in ropes (a wagonner's 20 ft rope)

Another correspondent writes:
Pigs were measured in scores elsewhere. In Newark cattle market, (which serves mainly Notts, Derbys & Lincs although buyers from supermarkets also attend), used scores up to decimalisation. The easy conversion £1 per score = 1s per lb was, thereby, lost.

A score usually means the number twenty. See my numbers website.

Counting sheep

Shepherds used to count sheep using special words. Click here for an account of this. This is part of my numbers website which covers other number systems including those from other cultures and historical periods.

Measuring potato fields

Another correspondent writes:

"During the Summer of 1969, after finishing my final exams at university (an engineering degree), I worked for the Potato Marketing Board as an Acreage Inspector. At that time, all farmers were allocated a set quota of acres for growing potatoes and were not supposed to grow more than that quota. If the set amount was exceeded, the producer had to pay an 'excess area contribution' (a fine) to the Potato Marketing Board.

"My job was to check on the reported acreages of potatoes that farmers had submitted to the Board. I had to provide a vehicle and find an Assistant (who was paid by the Board). The Assistant was vital, but I did not initially realise why. Anyway, I had an ancient blue van and found a fellow student in the year below, who was looking for a summer job, so we were all set to go.

"Now, at Grammar School and University I had been thoroughly used to working in metric units (MKS at that time) and had not used Imperial units for years.

"We were issued by the PMB with one tool only - a 22 yard Chain (a Surveyor's chain) - and six inch Ordnance Survey maps of the area. The chain had tags hanging down every 1/4 of a Chain (I think), so I had to seek some advice from a friendly surveyor on how to set about measuring land areas - especially fields that were not conveniently rectangular.

"He explained that the trick was to divide everything up into triangles and use the "half of base times height" formula - that way it didn't matter if the field wasn't square - and that ten square chains was a acre (which I didn't know). After that it was easy...

"Of course the Assistant was vital - to hold the other end of the chain. We would work this way: one of us would stand and the corner of the field and the other would walk along the edge for the full length of the chain. He would then stand still and the first person would then walk past him for the full length of the chain - and so on, until you got to the end of the field and found it was (say) 7.5 chains long. We then measured the adjacent side and discussed whether we needed to take another measure because the corner was not quite a right angle. That way we progressed to measure many fields over that summer - the job only continued during the potato growing season, of course.

"We also got very good at spotting potato fields from a distance - the farmers had not necessarily declared all the fields they had planted with potatos...

"One farmer we reported as growing in excess of his quota was the brother of the local MP, so he kicked up a stink to the Board at these "young lads in a van" who had reported him as growing too many acres. We later learnt that the Board had sent out a Supervisor to check our measurements and I was delighted to hear that we had been correct - he was over!

"I think the Potato Marketing Board and the quota scheme was wound up in the 1990s. I don't believe farmers are now limited in how many acres/hectares of potatoes they grow.

"I believe this was the last and only time I used Imperial units for a professional task."

Milk

Now we usually buy milk from the supermarket or corner shop in plastic bottles. In my childhood, most people had their milk delivered to their doorstep in glass bottles. The milk had to arrive before breakfast, so the milkman had to do his rounds very early in the morning while people were asleep. So he used an electric milkfloat which was nearly silent. (Earlier still, milk would be delivered by horse and cart, as described in Benny Hill's "Ernie, the fastest milkman in the West!") Every house had a regular order for milk, so the milkman would just leave the right number of milk bottles at the doorstep. You could leave a message altering the order, such as "An extra bottle please" or "No milk today" which was a song by Herman's Hermits.

The bottles held a pint of milk. When you had used the milk, you washed the empty bottle and left it for the milkman to collect so it could be reused. There was an advertising slogan "Drink a pint of milk a day", which got slurred into "Drinka pinta milka day." Milk was often referred to as a 'pinta'.

The milk bottles (when full) had foil lids. If you opened them carefully, you could put the foil lid back on the bottle to protect the milk. These foil lids were sometimes collected for charity. (There was no recycling as such in those days.) The lids were different colours:

The usual milk was silver top, with gold top for special occasions. The milk was not homogenised (except for red top) so the top part of milk was cream. You could use 'top-of-milk' rather than real cream.

These foil lids were very thin aluminium. After the milkman had left, the bottles were left outside the front door for some time before the household woke up and someone brought the milk inside. Blue-tits (small British birds) discovered that if they pecked at the tops, they could get at the milk. People were very annoyed to discover that their bottles of milk had little holes pecked in, and some of the cream had disappeared!

As the milkman had to visit houses to collect his money, often when the man of the household was away, there were plenty of jokes about what he got up to with the housewives!

Newcastle mining units

Coal on Tyneside was measured in chaldrons of 53 cwt, and keels of 8 chaldrons or 21 tons 4 cwt. There were 8 Newcastle chaldrons to 15 London chaldrons. A London chaldron contained about 28.5 cw or 36 heaped Winchester bushels. There was plenty of scope for misunderstandings in the coal trade 200 years ago. The chaldron was a unit of volume derived originally from 'cauldron', but if you were dealing in one particular material such as coal, a chaldron (of a particular volume) would always be the same weight. I suspect that this would lead to confusion between units of volume and units of weight (see shipping ton).

Lead was worked in bings containing 8 cwt of clean ore. The ore was refined into pigs of 1.5 cwt, and these pigs were sold by the fother containing 14 pigs for a total of 21 cwt. Silver was recovered from the lead at about 8 ozs per fother, although in the Alston area about 42 ozs of silver per fother were recovered.

A pocket metronome

A correspondent says "My better half found this item laying on the shingle at Bradwell on Sea. A tiny tape measure with J.Curwel & Sons on it. It looks 19th C. but what is it for measuring? As you can see the increments apparently make no logical sense...but they must! The tape has standard imperial inch divisions with tiny numbers denoting each inch. I think it would have been a yard measure as the last symbol is III... but with mysterious numbers placed at strange intervals that get closer and closer together in multiples of three, then four, then six. The numbers go from 60 - 144, but 144 is where the tape has broken so it may have continued a little further? The imperial inches go one way, the strange increments the other."

An answer:
"Yes it is a very old portable metronome. You hold the end of the tape and unwind it to the speed you want and then move it to get a pendulum effect. The time for the swing is approximately what is written on the tape. I have one in my collection of metronomes and it works quite well."

Another correspondent sent me the picture above and wrote:
"My parents bought me a pocket metronome for Christmas. This was the same as a measuring tape (which my brother got at the same time!) but had a non-linear scale. If I pulled it out to the 60 marking, held it by the end and let it swing like a pendulum, it gave me a reference for 60 beats per minute. At 120 it meant 120 beats per minute. Follow this through and each time you halve the length, the number of beats per minute doubles - hence the non-linear markings. My metronome had a cloth tape and the  housing was made of plastic with an internal spring and ratchet with a small button to allow the tape to be  rewound. As I remember, the scale was from 60 upwards - because of the non-linearity, it would have been to long to be used at slower rates! Also there was a length of tape beyond the last marking - it would not have swung for very long at short lengths. I don't remember the exact highest rate - probably around 160. I would guess that the tape was just over a yard when fully extended. If it was a pocket metronome, some of the Curwel tape is missing. From my school physics, I remember a pendulum would indicate 60 beats a minute when the length from the pivot to the point of the centre of gravity of the weight on the end was approximately 39 inches. I was taught not let it swing more than 20 - 30 degrees or it became inaccurate!"

If the name on the first tape (above) was J.Curwen & Sons, they were musical publishers, which makes sense.

Mohs scale of mineral hardness

The Mohs scale of hardness of minerals is an elegant method of working out how hard a mineral is. Mohs chose ten minerals of different hardness, and assigned to each a number from 1 to 10. A lower number mineral is scratched by a higher mineral. So you can work out how hard a mineral is on the Mohs scale by trying to scratch it with the different standard minerals. There are more sophisticated methods of measuring hardness nowadays, but the Mohr scale is widely quoted in all mineral books, and can be used by anyone to help to identify minerals (since a given mineral usually has a Mohr number). All you need is the standard minerals (which are quite easily available unless you want gem quality) and not mind scratching your specimen!

Click here for the Mohr's scale, plus photos and more information about the relevant minerals. This is part of my minerals website

There are plenty more of my websites here.

© Jo Edkins 2009 - Return to units index