The metals in general use are sheet brass, copper, tin plate, iron, and steel, rolled to the required thickness before reaching the workshop to be cut into blanks and formed into the required shapes. In most cases the Various metal alloys are.mixed according-to the requirements of the manufacturer, but for brass work a commercial metal is in use known as

"Best dipping metal,"this being mixed so as to be most suitable for dipping or gilding. Further, the metal known by this name stands more torturing whilst being worked than the ordinary common sheet brass, the reason being that it contains a greater percentage of copper. Some of the most important articles produced from brass are ammunition cases, which require a special alloy, as well as great care and judgment in arranging the number of processes and annealings, to enable the case to be worked into shape without rupture. The proportion of the metals forming the alloy suitable for cartridge cases is 70 per cent copper and 30 per cent zinc.

The metal sheets are usually measured or gauged by a wire or metal gauge. There are between twenty and thirty different wire or metal gauges in actual use, each gauge being considered by some manufacturer as the standard gauge that should be used for their own particular work. There appears to be no reason why one standard gauge should not be used throughout the whole industry, and if this could be arranged, much loss of time, trouble, and inconvenience to which manufacturers are now subject would be prevented. Many of the gauges now in use are practically worthless on account of the misleading and peculiar manner in which their sizes run. The appended table represents the gauges most frequently found in use by the trade.

It is customary to speak of the thickness of a sheet or wire as, say, No. 7 gauge, which means that the thickness is

that represented by the width of a slot against that number in some gauge. These numbers are given in the first column of the table, and the actual thickness in terms of an inch will be found for the several gauges in their respective places.

The second column (B) gives the values for the Imperial standard wire gauge, which is the legal standard in this country by the Weights and Measures Act of 1878, and as a consequence no contracts or dealings can be legally enforced that are made contrary to this standard.

The South Staffordshire Ironmasters' Association held a meeting in Birmingham on the 28th February, 1884, and by resolution adopted as their standard that shown in column H.

In column D is shown the proposed standard by the late Sir Joseph Whitworth. which is, as far as one can see, the only rational system contained in the table. It should be noticed that the number of the gauge is also the number of thousandths of an inch that measure the actual thickness of the sheet. It ought also to be noted that as the number of the gauge gets greater so does the dimension increase, whereas with the other standards the higher numbers have the smaller dimensions. The true solution of the gauge question appears to be in the adoption of the Whitworth standard, and in place of the present misleading plate gauges the general adoption of a micrometer graduated to read to 1/1000 of an inch for the determination of the actual gauge in each instance.

The old Birmingham wire gauge, which can be traced back for 45 years, is shown in column J, and the figures shown in column K refer to that known as the Birmingham metal gauge.

The gauges as per columns B, C, D, F, H, J, K, L are all in use. Manufacturers who roll metal for the trade have, consequently, an understanding with each of their customers as to which gauge their metal must be rolled to, and this makes it necessary that each lot of metal ordered be passed through the rolling mills in a separate batch.

A few moments' consideration will suffice to show how the use of these different gauges cause troubles and inconvenience to manufacturers. It seems that the only course open to manufacturers generally is to fall in line with the requirements of their customers upon the gauge question.

The figures given in column L are those of the American standard wire gauge. The want of uniformity in common wire gauges led the Brown and Sharpe Manufacturing Co., at the request of the principal American wire drawers and brass workers, to prepare this standard, which was worked out so that the variation between the_different numbers on the wire gauge should hot be so irregular as those numbers on the Stubs wire gauge. Previous to the introduction of this new American standard the Stubs gauge was the one generally used in America, but the Brown and Sharpe gauge has now taken the place of the Stubs gauge in America. The Brown and Sharpe Manufacturing Co., as gauge makers, have earned their reputation for high-class work, in accuracy and finish, and a special feature of their wire gauges worthy of attention is that, in order to familiarise the users of the gauge with the decimal equivalents of the gauge numbers, they stamp on the back, opposite to the regular gauge numbers, the decimal equivalents expressed in thousandths of an inch.