ACCURACY

Evening Post, Volume CIX, Issue 28, 3 February 1930, Page 11

ACCURACY

HOW IT IS KEPT

IN WEIGHTS AND MEASURES

STANDARD EXAMPLES

A most interesting room may be found in the basement'of the Labour Department's premises in Guuznee .street. There aro carefully guarded the standards of weights and measures which provide ■ tho Department with means of checking all'weights and measures in use in tile Dominion, and, under the Act, they arc thus enabled to see that every package sold by weight is correct, for the Department's activities extend to goods sold as well as to tho weights used by the seller. There is,a story of one of the old time inspectors of weights who proudly carried v daily burnished -brass standard weight round tho shops with him, regardless of the yearly loss through tho concession to appearances, but to-day the system is as exact as it is possible to make it. Bound the walls there arc many interesting pictures showing the development of scales from the earliest times. Strange to say the most exact scale to-day is the even-arm balance, which was one of tho earliest typos evolved^ The steelyard was a Roman discovery, and had som,e queerly' ornamented forms. Very different from tho weighbridges of to-day wero the cart lifts for the same purpOsq, surviving examples ■of i which aro to be found in .English villages, ornate por-tico-gibbets, with, tho block and tackle for hoisting the cart pendant from the steelyard far above tho roadway.

"Wo find that more scales examined in Now Zealand; give overweight than underweight," said Mr. H. E. Moston, the officer responsible at the head office of the Labour Department for administering tho Weights and Measures Act, "and so it can be scon that the Department protects tho seller as well as the customer." INSTRUMENTS OF PRECISION. There is in the room wJiere tho weights and measures are stored a wonderful collection of weighing > instruments of precision, by means of which tho copies of tho Imperial standards ■ are checked against tho weights taken' out for actual use by the Department's | officers. The largest of the beam scales, designed to weigh up to 561b, is so finely adjusted on agate bearings that if portion of a postage stamp be laid on it, tho beam will descend to its lowest position. What are the methods | by which the integrity of our weights \ ■and measures are maintained, and by which, in a practical sense, 16oz mako lib, 20 fluid buncos one pint, and .36 inches one yard? "Obviously the first essential," said Mr. Moston, "is to securo if possible a fixed standard which, for all timo and under' all conditions, shall remain the same. Nature has not in itself i supplied an invariable unit of- weight i or measure. It has been found necessary: to create* standards, and although standards have been brought into existenco in what, would seem to bo an arbitrary manner, it is certain that they have met the needs and convenience of-,mankind. The Now Zealand Weights and Measures Act, 1925, provides that tho Imperial standard ipound and the Imperial standard yard shall be-the source from which all weights and measures shall be derived; the gallon is legally determined by weight, viz., 10 standard pounds of distilled wator. The duty of maintaining the Imperial standards true and unimpaired is a sacred one, and is one which the Imperial authorities owe to tho Empire at large: The Imperial standard pound consists. of a piece of platinum made in the form of a'cylinder, measuring a little over 1J inches in height, with a diameter of slightly more' than one inch. This solid cylinder has a groove provided for the insertion of the points of ivory fo.rks by which it is lifted. • "The Imperial standard yard is a solid bar of bronze 38 inches long and ono inch square in section,. on which 36' divisions of one inch each have been marked off. These divisions represent the arm measurement of Henry 1., who ordained that the length of his own arm should bo the standard yard of cloth measure, an ordinance that is preserved to this day. These Imperial standards aro very carefully preserved by the Imperial - authorities and arc sealed up within the wall of the public stairway leading to the committee rooms of the' House.of. Commons. Once in every twenty years the standards, are taken out and checked with the copies of which there are four sets. Elaborate care is takei whilst ctiecking tlTe copies with the primary standard pound and the standard yard. The weights' are checked by means of balances capable of disclosing a difference of a minute fraction of a grain, and the yard is measured by an instrument which can'detect an error of one hundred thousandth part of an inch. NEW ZEALAND PRACTICE. • "As already stated the New Zealand weights and measures are derived from tho Imperial standard pound and the Imperial standard yard, and it is therefore necessary to have copies of the Imperial standards for use as standards in New Zealand. A complete new set of standards has recently been'obtained through tho Warden of Standards, London, to replace tho set which has been in use since 1860. These standards) are kept in a special standards room. The Minister of Labour is charged under.the" Weights and Measures Act with tho «afe custody and control of the standards. In the standards room there are also kept very intricate and sensitive instruments for the purpose of testing or verifying standards. As an instance of the extreme sensitiveness of the instruments it may be mentioned that one of the weighing appliances will disclose an' error of one grain in the case of a 561b weight—viz., ono part in 392,000, whilst an instrument used for .testing measures of length will detect an error of 100,000 part of an inch. I

"The two main purposes'- of the Weights and Measures Act is to secure uniformity in the weights and measures used throughout tho Dominion, and to provide for' justice being done betweon buyer and seller in respect to weights arid measures of goods. Judging from Biblical and other references it would seem that tho false balances and unjust weights have followed hard upon the heels of original sin. Paina and penalties have beon directed against these abominations' from tho time that simple barter gave way to more precise methods of exchange."The law in New Zealand requires that every weight, measure, and weighing instrument used in trade shall bo verified and ' stamped annually. The amount of verification work is in the aggregate considerable. Last year the number of weights, measures, and weighing and measuring instruments submitted for verification totalled 274,----777; of this number 14,707 were rejected as unjust or incorrect, and required to be repaired or replaced."