r4^ 
L A N D tV W A T E R 
July 20, 1916 
peiaturc and air acnsity being also lu'cded which I omit 
to specify). The question then is, if f buy a pound of tea 
am I bujing a mass-pound of tea, or a weight-pound of 
tea ? In France, where the matter is put on a sound 
scientific basis, it is the mass of tea that is measured out 
to me. In Great Britain, our Acts of Parhamcnt have 
been so drawn that it is doubtful which of the two is 
being purchased, and whether the weight cr mass is the 
true standard. Our standards of so-called weight are, in 
truth, standards of mass. 
Our system of estimating weight is not only un- 
scientific, but clumsy. Thus we have 16 oz. =1 lb.; 
141b. — I stone; 8 stone = i cwt ; 20 cwt. = i ton. 
This is called the avoir-du-pois system. For weights 
less than an ounce we have no prop:;r divisions. All that 
we can do is to have recourse to the apothecaries whose 
grain weight weighs 437! grains to the avoir-du-pois oz. 
Apothecaries sell their drugs by avoir-du-pois. And 
they use the avoir-du-pois fiuid measure of which the 
oz. weighs 437.1 grains, but for making up prescriptions 
they use for solids the old apothecaries' weights with an 
oz. of 480 grains (the grain being the same as the grain 
avoir-du-pois). They divide the apothecaries' oz. into 
drachms which, however, have a different weight from 
the weight of the fiuid drachm. 
The method of linking the systems of measures of 
length on to those of area, volume, arid weight is clumsy 
in the extreme. As has been seen, 640 acres make up 
a square mile. Whence it follows that an acreside 
measures 6<).52 yards. 
There is no connection between the measures of length 
and volume unless one can call the fact that a gallon 
measures 277.2 cubic inches a connection. • 
The connection between volumes and weights depends 
on the fact that a gallon of water weighs 10 lb., whence, 
as has been said, an avoir-du-pois oz., whether solid or 
an oz. vohime of water, weighs 437^ grains and an 
avoir-du-pois fiuid minim of water weighs .gi grains. 
Now let us compare the British system with the decimal 
metric system, the use of which is now permissible. 
Here the unit is the metre =3 ft. 3jin., nearly. 10 
metres = I deka-metre and then upwards by Greek 
prefixes we go to the kilometre, and downwards by Latin 
prefixes to the centimetre and the millimetre. The 
unit of area is the square metre. 100 square metres 
is called an are, 10,000 square metres constitute a 
" hectare," about 2^ acres, the usual measure of landed 
property. The units of volume are simply the cubes 
of the linear measures. So that the litre, or 1,000 cubic 
centimetres (about a quart), is the ordinary measure 
and goes upward by Greek prefixes and downw-ards by 
Latin prefixes in a similar way to the metre. 
The unit of quantity is the mass of a cubic centi- 
metre of pure water, called the gramme, and goes upwards 
to the dekagramme and kilogram and downwards to the 
dcci and Centigram in an exactly analogous fashion. 
If you want to make a cubical box containing a Utre 
you make it measure 10 centimetres each way, and the 
water necessary to fill it will just weigh a kilogram. Here 
>'ou have units of length, volume and mass connected 
in an easy and natural measure. 
Let us now take a few examples showing how con- 
venient this system is as compared with our own. You 
are told to encourage early potatoes by sprinkling on 
them ^ oz. per square yard, of nitrate of soda. You 
have an acre of potatoes and you want to know how 
much stuff to buy. An acre contains 4,840 square yards. 
You, therefore, want 2,420 oz., that is to say ^'"^ ° lb. 
^151 lb. —I cwt., I quarter, and 11 lb. A French book 
tells you to put what is nearly the same thing, 18 grammes 
to the square metre, which at once is seen to be 180,000 
gram Ties, or 180 kilograms to the French hectare of 
2 J acres. 
You have to make a mildew wash for fruit trees of 
I part by weight of liver of sulphur in 1,000 parts of 
water. Your spraying machine will contain 15 gallons. 
The calculation then proceeds. 15 gallons weighs 
150 lb. = 150 X 16 oz.= 2,400, which, divd 'd by 1,000 
gives you 24 oz. as the quantity of liver of sulphur to 
put in. In France you do it thus. My can contains, say, 
bo litres. This weighs 60 kilograms. Of this one- 
thousandth part is 60 grammes, which is the quantity 
rc:|uiied. No wonder English gardeners trust to rule 
of thumb. A few experiences of the use of a bit of chalk 
on a greenhouse door will soon make you wish that our 
British weights and measures were in the limbo to which 
scientific men in our own country have long consigned 
them. Suppose you measure up your property and find 
that it is 8 acres 3 roods and 6 perches, and the r.itc 
collector proposes to rate it as of yearly value for agri- 
cultural purposes of £1 15s. an acre. Here is the calcu- 
lation : 8 -t- — -i — 2~- X 35s. =£18 15s. 7id., and anyone 
who will do the calculation will be surprised to find what 
an amount of multiplication and division it involves. 
But in France. If you had, say, 5 hectares, 400 decarcs 
and 200 ares of land, it would be written 54002 hectares, 
which at (say) ,4375 francs per hectare, would be com- 
puted by one multiplication. 
Instances like the above might be indefinitely multi- 
plied. The whole British system of weights and measures 
has been already cleared out for ever from scientific 
institutions in Great Britain. 
Difficulties of Changing 
Why should it not be finally abolished ? A con- 
i^idcration of this matter will show us where the difiiculties 
lie. In the first place, it seems clear that the easiest 
part of the change would be to adopt the metric system 
of weights. The conversion of existing weights would 
not be difiicult though it might cost much for new weights. 
The conversion of fiuid and volume-measures would 
be easy when once the new weight system had been 
adopted, but here the loss would be greater. Metal 
pots could be converted or recast, but glass divided 
measures would become useless. 
So far it seems mostly a question of money. When, 
however, it came to measures of length greater difficulties' 
present themselves, and the change would have been 
more easy to carry out 100 years ago than now. For 
example, the systems of screws and screw threads present 
the greatest trouble. There arc four widely used systems 
of screws in this country. The Whitworth, the British 
Association, which is a sort of translation of the Swiss 
threads, and the systems in use for pipes for steam, 
water and gas and other similar purposes. 
This screw system is based on the inch, and to alter it 
satisfactorily would mean that every screwmaking 
lathe or other tool, would have to be refitted with a new- 
leading screw, or else with a pair of change-wheels for 
converting inch motion into centimetre motion. 
It would be impossible for years to obviate the necessity 
oi making and keeping nuts and screws of the old patterns 
for repairing machinery. A beginning might, however, 
be made with screws for the future. 
The rearrangement of the ordnance maps Would not 
be difiicult by a simple alteration of scale, but the re- 
marking of the measurements of acreage would be 
imperative. The decimal money systems I need not 
describe or illustrate, as foreign travel has familiarised 
the public with its features and advantages. Of course 
a clean sweep would have to be made of a number of 
trade measures. The jeweller's troy weights and precious 
stone weights would have to go. Also the truss and load 
of hay and straw, firkins, ankers, pottles, kild.;rkins, 
runlets, hogsheads, punchaons and butts would dis- 
appear. The fathom, chain and cable would vanish, as 
also the rod of brickwork, the ■ square " of timber, the 
"standard" of deals, "empress" and "duchess" 
slates would be no more, and " hanks " of cotton and 
string would have to change their sizes. Even the guinea 
would be obsolete. W'c should seem to lose our history, 
our literature and our aristocracy all together. But the 
benefit would be great. 
The truth is, that the change has already taken place 
in scientific and medical work, and that most of our 
engineers are perfectly acquainted with the metric 
system, and if trade is to be reorganised after the war a 
bold step of a legislative character would be borne with 
equanimitv. But voluntarv effort would never do it 
alone. If'it is to be done, then, like the Daylight Saving 
Bill, it must be established by law. It is a step that must 
be taken sooner or later, and it would be probably wise 
to make preparations for its introduction at once so it 
could be put into force directly the war ends and the 
revival of trade begins. 
