Specification of the Patent granted to WILLIAM WILSON, Smith, of the City of Edinburgh, and County of Mid Lothian; for his improved Plan of making, adjusting, and stamping, Scale-weights, Dated April 30, 1801. With a Plate.

To all to whom these presents shall come, &c. Now KNOW YE, that in compliance with the said proviso, I the said William Wilson do hereby declare, that my said invention is described in mauner following; that is to say: My high scale-weights, such as have always been used with handles, of one pound and upwards, are made solely of hard and durable metals, without any addition of lead. They are adjusted and stamped by means of a small piece of indestructible metal, inserted into, or fixed upon, the cast-iron body of the weight, Their form is peculiar in several respects; and they are finished without the assistance of any metal softer than wroughtiron. My flat pile-weights, of four ounces and upwards, are likewise adjusted and stamped by attaching to them a piece of metal harder than lead, yet capable of receiving the impression made by the stamps.

When a high weight, of the kind here described, is cast in sand, or in a metallic mould, an opening, which appears in Fig. 1, Plate V. is left in it, of any form that will suit its position, of a sufficient deepness for the purpose of adjusting, and its surface large enough to contain the stamps; which opening is afterwards exactly filled with a piece of metal, represented by Fig. 2, heạvier or lighter, as may be necessary, to render the weight perfectly conformable to the standard. When the adjusting metal is too heavy, its weight is diminished by

filing off part of its bottom, or giving it feet, as in Fig. 3, in order to lessen its size without reducing its height; or by placing below it, for the same purpose, a bit of rolled iron, more or less turned up or down at both ends, as in Figs. 4 and 5. Upon the first mentioned piece of metal, either cold or hot, the stamps are impressed, which ascertain the number of pounds, and show the maker's name, or initials. The metal used for adjusting and stamping is fixed by two iron pins, put into the body of the weight when it is cast. These pins, which are distinctly seen in Fig. 1, go through the piece of metal, and are rivetted on the outer side, or fixed in any other sufficient manner. When a piece of metal is placed upon the surface of the weight, the method of fixing it is precisely the same; only it is attached to a flat weight, by making the rivets go entirely through the weight itself, and it may be fixed to a high weight in the same manner. It is not improbable, however, that, with respect to the latter, the following method may be adopted. The weight to be cast with a dove-tailed aperture in its top and side, as represented by Fig. 6. A piece of metal, represented by Fig. 7, to be fitted to the aperture, and put in from the top; and, in order to prevent its moving upwards, a screw-nail to be fixed in the upper part of the piece of metal, with its point inserted into the body of the weight. In this case the stamps are partly on the top, and partly on the side; and the weight of this piece of adjusting metal is varied by hollowing, or filing off a part of it behind, as in Fig. 8.

A weight, cast with such an opening as I have described, may be adjusted and stamped by means of lead, brass, and various other metals; and perhaps even substances which are not metallic, or compounded substances, might be found to answer those purposes. The

opening

opening may be situated in any part of the weight. The piece of metal with which the opening is filled may be fixed by nuts and screws, and by other methods; or a piece of another form may be attached to the surface of the weight, in any way that may be thought proper. The weight, moreover, may be adjusted by reducing its wrought-iron handle, upon which also the stamps may be impressed, the ring being properly formed for that purpose. But the metals which I prefer are wrought-iron or steel; the substitution of an indestructible substance in place of lead being intended to prevent any deviation from the standard by common wear, while every thing else is so contrived as to render it impossible to mutilate the weight without putting it in the power of any one who examines it, merely by ocular inspection, to detect the fraud. For the cast-iron part of the weight admits of no diminution without having its surface and its form visibly marred; and the wrought-iron cannot be filed, or lessened in any way, without defacing the stamps: even the heads of the rivets and screw-nails are secured, by being stamped after the weight is finished. I rivet the adjusting metal flush with the surface of a high weight, but raised somewhat above that of a flat one; and I put it into the upper part of the body of the weight, where the stamps are most advantageously situated.

With respect to the form of my high weights, the round shape in common use is adopted with the following alterations and improvements. Their tops are considerably elevated, (as represented by Fig. 1,) that the dust may easily fall off; for hollow tops seem as if they had been contrived for the purpose of retaining it, and must either make the weights heavier than the standard, or, by occasioning frequent cleaning, reduce them below it. The edges are likewise rounded off, in order to prevent

them