METRIC SYSTEM

Evening Post, Volume XCVIII, Issue 134, 4 December 1919, Page 14

METRIC SYSTEM

AN EVERGREEN PROBLEM

SOME OF THE PROS AND CONS

THE USE OF BRITISH UNITS.

It is by no means improbable that the introduction of some more standardised system of units will, in the near future, be once again pleaded for this country as an essential to industrial expansion, writes the engineering correspondent of the London Daily Telegraph. Pew, if any, are unaware of the almost hopelessly chaotic nature of the system or systems now in vogue, and few, moreover, are perhaps aware of the patient and persistent attempts which have been made for nearly a century to secure the introduction of a saner basis for weights and measures than that now in operation. Thus, as far back as 1824, a "pound and mil1' system of coinage was recommended, while as recently us 1907 the House of Commons rejected, by a. narrow majority of 32, a measure design ed to secure the compulsory adoption of the metric system. The attitude of Great Britain towards the whole question is being watched by other countries, and in 1910 the Australian House of Representatives, by a majority of 35 votes to 2, resolved upon the adoption of the metric system following its compulsory introduction in Great Britain.

Renewed activity in some directions is already in evidence. A large section of opinion, recognising that some change in our system must come sooner or later, urged that the present conditions provide an opportunity to "do it now." Possibly equally weighty opinion hesitates to believe that the advantages of- any new system will offset the chaos of the period o£ transformation. Frequently very fictitious arguments are urged against the present system. It must be recognised that no argument against present units can be based on the arbitrary adoption of the yard as defined by Act of Parliament. The fact that the metre is supposed to be about one ten-millionth part of the distance from the Pole to the Equator provides no ground for its adoption in preference to the yard. The metre is equally as arbitrary as the yard. Certainly, however, the advantages of the metric system lie in the simplicity of the units on a strictly decimal basis, and the very close relation existing between the relatively few units of mass length and volume. All this must be agreed, and if it can be definitely determined that it will be to the advantage of British* industry, then the inconveniences of any period of changeover would be more advantageously met now than later. The similar change has before been made by nations, which have subsequently enjoyed remarkable industrial expansion.

THE PRESENT TANGLE.

It is, however desirable that the issue should be clearly understood Our existing system—or absence of system— is characterised by lack of correlation between, different units, by the use of multiples of two, three, six, and twelve in place of ten in the decimal system, by the totallly confusing use of a single term for many slightly varying units, and by the fact that it does not harmonise with the system in detail adopted by any other country. Methods of eystematisittg our units do not necessarily resolve themselves into the adoption of the metrio system in its entirety In an early .stage the elimination of many superfluous units and the partial decimalisation of others would go a long way towards clearing away the difficulties in internal industry and external trade. Even if the metric system were adopted, it would be desirable to omit all units of smaller multiples than one thousand. Thus the gramme and the kilogramme would suffice with the milligramme as a still smaller unit for most purposes. Similarly the kilometre, metre, and millimetre might be regarded as all-sufficient units of length but here exception could be made in favour of the retention of the centimetre on account of its association with the gramme through the cubic centimetre of water under standard conditions. Further, though in'no sense associated with the metric system, a dcci malisation of money could be easily and advantageously adopted, and has been most powerfully urged. In such a system it is recommended that the present sovereign should constitute the unit and be subdivided by stages into 1000 mils, this mil thus being a little less than a farthing. Intermediate values would be the half-sovereign (500 mils), double florin (200 mils), florin (100 mils),, halfflorin (50 mils), and quarter-florin (25 mils or sixpence) Bronze coins of smaller value would vary from the penny, half-penny, and farthing by only four per ceni, II is by no means improbable that the introduction of such a system will mark the beginning of whatever changes in our system of units may ultimately be effected.

THE ENGINEERING ASPECT

Next, a limited disturbance would be effected by the adoption of a, decimal system of weights. The kilogramme is equal to 2.2M1b, and little usage would soon familiarise the public with the use of the half-kilogramme as an approximation to our pound. Ounces both averdupois and troy could, and would, soon be dispensed with. On the other hand, 1000 kilogrammes (equal 22041b) is, already in use as the so-called metric ton, and, as will be seen, approximates to our present ton. In many operations the long ton (22401b), short tori (20001b), and metric ton are closely used, and any two could easily be dispensed with in favour of the third, which, as an easy step towards the wider adoption of the metric system could .be the metric ton So far the changes proposed are more of a decimal than purely metric character, and would provide us with decimal units approximating to those at present in use The problem, however, does not appear so simple when we come to the attempt to effec* the change over the metric and millimetre as standards of length. A little consideration will show the magnitude of the change involved, and in engineering the effects are strikingly observed Thus, in a metric agitation of a few years ago, a careful estimate made by a large engineering concern showed that the adoption of the metric system would involve an expenditure of £100,000 to £150,000 for drawings, patterns, jigs, gauges and specia.l tools

GREAT DIFFICULTIES IN

APPLICATION.

In engineering, standardisation lias already been carried to a remarkable degree', so that small fittings can be bought with a guarantee that they will fit. The adoption of the metric system would introduce difficulties of almost unrealised magnitude At present • rules and gauges are in fractional parts of an inch, and very frequently in thousandths. The relation between the inch and centimetre is such that conversions from frac tions of an inch to millimetres would introduce strange figures Thus a rod becomes a 6.35 millimetre rod, and to change such standards as thicknesses of sheets and1™ any gauges to exact metric units would be a departure the wisdom of which would demand serious thought.

From the point of view of its bearing on foreign trade it has to be observed that a large export trade to foreign countries has already been a matter of experience in Great Britain,, and this independently of the metric system. The

supply of goods of the required type, quality, and quantity, and in a given time, are obviously more important factors than expression of dimensions in terms of new units. As far as catalogues are concerned, dimensions are easily expressed therein in any number of systems, but the introduction of a purely metric system into this country, and also into America, introduces problems which would appear to be insoluble On the other hand, standardisation is the order of the day, and the gradual elimination of unnecessary and conflicting units cannot fail to be of service in industry and to the country as a whole.