mode hitherto made use of; and such information I am enabled to give, from very ample experience and proof, the machine having been erected a considerable time, and repeatedly applied to cylinders, pumps, &c. of various dimensions, all which have thereby been bored with much superior accuracy and expedition.

It is well known that a hollow metallic cylinder, when laid in a horizontal position, has, from the pressure of its upper parts, a tendency to assume the elliptical or oval form; i. e, the horizontal diameter of that cylinder will be greater than its vertical diameter; and this, in a greater or less degree, in proportion to the size and strength of the cylinder: such departure from a true cylindric figure is rendered still more considerable by being strongly chained or bound down to the frame or carriage on which cylinders have heretofore been bored, This source of inaccuracy, (formerly unavoidable in slender and large cylinders,) so much and so justly complained of, is totally done away by my new mode of boring. The cylinder itself standing vertically with respect to its axis has no tendency to change its figure, and the screws, clamps, &c. made use of to fix the same immoveably in its position, proceeding from the arms in the upper and lower metallic rings of the machine, embrace the flanches, or other parts of the cylinder most capable of resistance, in so many points, and on all sides so equally, that not the least deviation from a true circle is discoverable in the bore thereof. The importance of this most essential property in steam-cylinders, pumps, &c. I think needs no elucidation. The destruction of steam, loss of power, and frequent renewal of expensive packages attendant upon an untrue cylinder, working-barrel, &c. are too well known by every practical engineer, and too severely

severely felt by every intelligent proprietor of such an engine, to require any particular exposition.

Besides the great superiority in the precision of boring above mentioned, and the evident advantages recited in the specification of boring through without any change or alteration in the cutters, and thereby producing a more uniformly exact and smooth bore than can possibly be obtained in the horizontal mode, the comparison relative to the time and attendance requisite in each method to the performance of the same work will I trust be deemed worthy some attention. From the experience I have had in both methods of boring, I am fully enabled to state, that of the time necessary to fix and bore a cylinder, after the horizontal mode, at least three-fourths may be saved by the adoption of my method in cylinders of moderate dimensions, but those of large diameters I can fix and bore completely in one-fifth or one-sixth of the time usually required to do the same in the way hitherto followed. From an inspection of the machine, it will also appear, that by having a knowledge of the speed of the sliding head and the cutters, and also of the train of wheel-work impelling the same vertically down the cylinder, the precise time of boring any article may be exactly known, and will always, in the same gear, be proportional to the length of that article. Hence no attendance will be necessary from the first setting to work to the completion of the same; nor even then will the neglect of a few hours be productive of the least injury to the work. But, in the common mode of boring, attendance must be constantly given by one, if not by two persons, either to press forward the cutters by hand and lever, or frequently to change the position of the levers in the axis of the pinions, and to raise the weights, &c.;

and

and should any neglect occur in the finishing course, the cylinder at least mustbe bored again if it be not irre parably injured.

The central rack with the pinion and drum a, b, and c, not described in the specification, and the wheel and pinion de connected therewith, is a sketch of the method I employ to lift or raise the boring-rod, head, &c. out of the cylinder when bored and ready to be removed away, or to change the boring head and cutters. This, or any other contrivance to effect the same, may be adopted as may best suit local circumstances.

To the Proprietors of the Repertory of Arts, &c.

I am, Gentlemen, &c.

MICHAEL BILLLINGSLEY.

P. S. I beg leave to add, that I have removed from Birkenshaw to Bowling Iron-works, near Bradford, Yorkshire, and have made an assignment of one moiety of my patent-right to John Sturges, Esq. one of the proprietors of those works, who is now erecting an extensive mill upon the patent principle, and who will be happy to treat upon liberal terms with any reputable engineer, or proprietor of a boring mill, desirous of adopting my im provements.

Specification

Specification of the Patent granted to THOMAS RICHARDSON, of Iron Acton, in the County of Gloucester, Tanner; for Improvements in the Arts of preparing, colouring, and joining, or uniting, the Skins of Sheep and Lambs:

Dated June 26, 1802.

To all O all to whom these presents shall come, &c. Now KNOW YE, that in compliance with the said proviso, I the said Thomas Richardson, do hereby declare that my said invention is described in manner following; that is to say: After the said skins have been tanned in the usual manner with oak-bark, shumach, minerals, or other substances, fit and proper for that purpose, or otherwise treated, for the purpose of converting the same into a permanent and durable substance, whether known by the name of leather, or by any other denomination, the said skins are taken from the vats, and prepared by beat ing the same on the wool side, to discharge the loose pieces of bark and other impurities; after which they are well washed in a running stream, and left to soak in clear water till the next day, and then the beating and washing are to be repeated, and the skins again left to soak; and in this manner they are to be treated until the smell is dissipated and the wool appears of a clear good colour, which will generally take place in the course of six or eight days. The skins are then to be scoured in the usual manner, with a strong ley of wood and pearl ashes, or soap, and left to drain on the horse, when they must be carefully examined; and those which are intended to be dried of the plain colour the wool takes from the tan vats, are to be hung on the hooks for that purpose; but those intended for fox or tan colour are prepared by

plunging

The

plunging and keeping them (with occasional agitation) in strong clear lime water, until the colour is as deep as required. The lime-water is prepared as usual, by slaking a few pieces of good quick-lime in water, and stirring the mixture, which is then suffered to subside, and the clear part decanted off. I must also remark, that the lastmentioned colour may be obtained in many other ways with lime and water, but that, after many trials, the method here described was found to be the simplest and most effectual. When the skins are perfectly dry they are in a fit state for colouring, of a variety of fancy colours, in imitation of animals, or in any other manner, as follows. First, the skins intended to be joined must be carefully matched, as well with regard to the length as the colour and thickness of the wool, and marked. whole is then to be beaten and carded, to make it as clean as possible, and taken to the dye-house. If the skins be intended to be spotted or figured, whether on the original coloured ground, or upon any other colour or tinge which may have been communicated to the wool, a board, or other similar contrivance, must be prepared, of the length and breadth of the skin, and perforated with a variety of openings, according to the fancy of the manu facturer; and the skin is to be spread upon the said board, and the wool drawn through the holes, by means of small hooks, or other well-known implements, so as to fill the said holes. The board supporting the skin in this situation is then to be suspended horizontally to a pulley, so as to be drawn up or let down at pleasure. When the intended colouring stuff is ready, the board is to be gently let down, and suffered to float upon the liquor, and then drawn up and aired, and again let down till the colour is sufficiently fixed; and, during this process, care must VOL. II. SECOND SERIES. U u bu