and strong chamber, or place between the said touch-hole and A. D. 1807. vent, and the plug or sliding piece, or other piece by which the communication with the external air is cut off, a small portion of some or one of the chemical compounds herein before mentioned (for example, as for priming to a musket about the eighth part of a grain); and when the required discharge is to be made, I do cause the said chemical compound or priming to take fire and explode, by giving a stroke, or sudden and strong pressure to the same, communicated by and through the said plug or sliding piece, or other piece before mentioned or described, in consequence of which the fire of the priming is immediately communicated to the contents or charge placed within the said piece of artillery, fire-arm, mine, chamber, cavity or place, and the discharge accordingly follows.

means.

And, secondly, I do hereby further declare, for the better Mechanical illustration of my said invention, and as auxiliary to the use thereof in relation to the mechanical parts thereof, that I have hereunto annexed drawings or sketches exhibiting several constructions which may be made and adopted, in conformity to the foregoing plan and principles, out of an endless variety which the subject admits of.

The invention claimed by this specification is, the application of these chemical compounds to be ignited by percussion to the purposes expressed by the title of the patent. The subject-matter of this and Hartley's patent (ante 54) may be classed together, each being for the application of a known thing to produce a particular effect. The preceding specification appears to be framed in strict accordance with the terms of the proviso of the letters patent; that proviso requiring the grantee particularly to describe and ascertain the nature of bis said invention, and in what manner the same is to be performed. Law and Practice, Pr. F. XIII. n. q. The portion of the specification printed above is in accordance with the former part of the proviso, while the annexed drawings are in compliance with the latter part of the proviso. The patentee having succeeded in an action for the infringement of this patent (Forsyth v. Riviere, infra), against a party using a lock of a different construction to any shown in the annexed drawing, the night of the patentee to the exclusive use and application of the detonating mixture as priming was

*

In witness, &c.

established, whatever the construction of the lock by which it was discharged. This is founded on the following important principle, which has been recognised in several subsequent cases, that a person who discovers a principle, and also some mode of carrying that principle out in practice, so as to produce or attain a useful effect or result, is entitled to protection against all other modes of carrying the same principle into practice for obtaining the same effect or result. See post, Crossley v. Beverley, per Alderson, B. in Jupe v. Pratt, and Neilson v. Harford.

Forsyth v. Riviere.

In this action for the infringement of the above patent, tried before Abbott, C. J. &c., the plaintiff had a verdict. On the question of priority of invention, Abbott, C. J. held, that if several persons simultaneously discover the same thing, the party first communicating it to the public under the protection of letters patent becomes the legal inventor, and is entitled to the benefit of it. See Chitty's Prerog. Crown, 182.

HALL'S PATENT.

Letters patent, 3d Nov. 58 G. 3, A.D. 1817, to J. S. Hall, of Title. Basford, &c., for a "method of improving every kind of lace or net, or any description of manufactured goods whose fabric is composed of holes or interstices made from thread or yarn, as

Specification.

usually manufactured, of every description, whether fabricated from flax, cotton, wool, silk, or any other vegetable, animal, or other substance whatsoever."

The object of my invention is to remove from every kind of lace or net, or other goods of the description above mentioned, all superfluous and loose fibres, or ends of fibres, which are not so bound and twisted into the thread or yarn of which the lace or net or such other goods is composed, as to form a part of the solid body thereof. These superfluous fibres do not contribute to the strength of the thread or of the lace or net or such other goods as aforesaid, but form a kind of fur or wool around the threads, which makes them appear thicker than they really are, and also fills up the meshes, holes, or interstices, of the lace or net, or such other goods as aforesaid, and makes them appear indistinct and woolly. My method of improving lace or net, or such other goods as aforesaid, is by passing them through, or at a very small distance over, a body of flame or fire, produced by the combustion of inflammable gas, while the said flame, or the intense heat thereof, is urged upwards, so as to pass through the holes or meshes of the lace or net, or such other goods as aforesaid, by means of a current of air which is produced by a chimney fixed over a flame immediately above the lace or net, or such other goods as aforesaid. The action of the flame is to burn, singe and destroy as much of the said superfluous fibres or fur as may be removed without injury to the lace or net, or such other goods as aforesaid.

A long piece of lace or net, or such other goods as aforesaid, or several pieces united together so as to form a large sheet, is made to pass between two rollers mounted one over the other, like the rollers of a flatting mill, and the lace or net, or such other goods as aforesaid, are further to be extended over other rollers so as to spread part of the lace or net, or such other goods as aforesaid, in a horizontal position; beneath this part the flame is applied, and the rollers being turned round will cause the lace or net, or such other goods as aforesaid, to pass through or at a very small distance above the flame, so that every part of the piece shall in succession be subjected to the action thereof, and the velocity of the movement must be so regulated that the superfluous fibres of the lace or net, or other goods as aforesaid, will be acted upon in its passage through or over the flame, without having time to injure the lace itself.

It must be obvious that the rapidity of the motion must depend upon the nature of the lace or net, or such other goods as aforesaid, and the intensity of the flame. It is of course impossible to give any general description of the motion that will be applicable to different cases; a slight trial, however, will be sufficient in each instance to ascertain and regulate the velocity. A regular and uniform motion will of course be most convenient

and advantageous. The operation may be repeated as often as A. D. 1817. is found necessary to effect the required improvement of the lace or net, or such other goods as aforesaid, and the operation will be most readily effected if the two ends of the piece are united together, so as to form an endless band, which being extended over a system of rollers, will circulate about the said rollers when they are turned round, and so every part of the endless band will pass and repass continually through or over the flame. The apparatus for the production of the inflammable gas may be the same which is well known, and in use for the purpose of illumination. The gas is to be conducted in pipes to the machine, and to enter into a tube which is placed horizontally beneath the lace or net, or such other goods as aforesaid; when the lace or net, or such other goods as aforesaid, has been sufficiently operated upon by the flame acting on one side, the piece is reversed, and the other side is subjected to the action of the flame.

The drawing hereunto annexed represents a system of rollers to operate upon lace or net, or such other goods as aforesaid, by the flame of inflammable gas. (Description of the drawing.)

As the lace or net, or such other goods as aforesaid, will be somewhat discoloured by the operation, it may afterwards be bleached by any of the processes in common use. The operation is generally performed once before the goods are bleached; they are then half-bleached, and the operation repeated; the bleaching is afterwards finished. The above apparatus, or combination of machinery, is conveniently adapted for the purposes of the said invention; but I do not claim the exclusive use of any apparatus or combination of machinery, except in connexion Claim. with and in aid of the application of the flame of inflammable gas to the purposes above described in this specification.

The subject-matter of the preceding patent is the improved manufacture of lace, resulting from singeing off, by the flame of gas, the superfluous fibres which bang about the thread, which process is called gassing the lace; and the specification describes the means by which the invention is to be performed. No objection was taken at the subsequent trial to the sufficiency of the specification, but only to the subject-matter of the patent.

Improvements in existing manufactures constitute a very large proportion of the patents which are granted, and it may be useful to point out some of the instances in which such improvements have been effected, by the application of some known substance or thing to the particular purpose of the improvement of the existing article.

The

The manufacture of cotton velvets was the subject of several successive improvements. loose and uneven fibres were first removed by the use of razors; next they were singed off by spirits of wine; next by the application of a hot iron resembling a weaver's drying iron, and finally by drawing the goods rapidly over an iron cylinder heated to redness.

In witness, &c.

The manufacture of cloth has been the subject of many improvements. The shearing cloth from list to list by a rotary cutter, the cloth having been previously shorn from list to list by shears, and also from end to end by a rotary cutter, was held a separate and distinct invention. See per Lord Tenterden, C. J., Lewis v. Davis, 3 Car. & P. 502.

The immersion of cloth manufactured in the usual manner in hot water, according to Daniell's patent, improved the value of the cloth very greatly.

In the manufacture of paper, the conducting the paper against a hot cylinder, according to Crompton's patent, constituted a great improvement in the drying and finishing the paper.

It is important to consider these and similar inventions in respect of their final effect or result on the manufacture, since by this alone can the utility and importance of the invention be ascertained. See ante 71, n.e, and Derosne's patent, post.

HALL V. JARVIS AND FRANCIS Boot.

In the K. B. Dec. 17, 1822. Cor. Abbott, C. J.

Sir J. Copley, S. G. (Scarlett, Denman, and Reader), for the plaintiff.

The object of the patent for an infringement of which the present action is brought, is to improve the texture of lace and other articles of a similar description; till within the last twenty years, a great part of the lace used in this country was imported from abroad, but within that period such improvements have been made in the manufacture in this country, owing to the inventions of Mr. Heathcoat for making lace by machinery instead of by hand, that a large quantity of the lace now made in this country is exported. There still, however, remained one great desideratum in our manufacture of lace. The material used in this country was principally cotton, that used on the continent principally flax. The cotton was cheaper, and could be spun to a finer thread; but the cotton thread had the disadvantage of being covered with a species of wool, from which that spun from flax was free. The lace from flax was thus much clearer than that from cotton, which had a sort of whiteness, or fogginess, in its general appearance, to the great diminution of its value. It occurred to some, that this defect might be removed by the action of heat, which had been already applied to removing the same kind of unevenness from muslin, by passing it over rollers of hot iron, and from mits and stockings by singeing. It occurred to the plaintiff, Mr. Hall, that the flame of gas might be applied to this purpose, and he tried a pipe with a great number of perforations, so as to give a continued line of flame, over which the lace was passed, with a motion just rapid enough to singe the little fibres composing the wool, without injuring the texture of the lace. This first attempt, however, failed; although the texture of the lace was open, the flame would not pass through it; it was impeded by the law of nature, first discovered by Sir H. Davy, and since applied so admirably in his safety lamp, viz. that flame will not pass through wire gauze so as to communicate with the outward air. The wire gauze steals away the heat of the flame (a), and

(a) It should be observed, that this is strictly true only when the gauze and flame are steadily in contact, or brought slowly together. If a piece of wire gauze be brought down slowly, steadily, and horizontally, over a jet of flame, the flame will not pass through it; but if the gauze be brought down suddenly, so as to impinge as it were upon the flame, the flame will pass through. This is in strict accordance with another law of nature-that

in the destruction or communication of momentum, i.e. motion to matter, time must be consumed. The upward current which constitutes a flame, can only be diverted gradually, and if the gauze be brought into contact with it sufficiently rapidly, some of the flame will be forced through. The additional current upon which the success of Mr. Hall's invention depended, further illustrates the same law.

accordingly, in the safety lamp, the fire damp will pass through A. D. 1822. the wire gauze into the lamp, and there burn with a bright flame, but the flame will not pass out of the wire gauze so as to communicate with the outward air. So Mr. Hall found that the flame, though increased to a greater degree, would not pass through. This he obviated by the production of a current of air, by means of a narrow chimney above the line of flame, between which and the flame the lace was passed; the flame was thus forced through the interstices of the lace, burning away the fibres on their sides. The appearance of the lace is thus improved, its fabric is not injured, but rather hardened and improved; the greater part of the lace now used in this country is improved in this manner, and the exportation of it has in consequence increased to a very great degree (b).

utility.

The witnesses proved, that no means of effectually destroying Evidence of the furs and fibres of the lace were known previous to the plain- novelty and tiff's invention; that the method of singeing by means of hot rollers, as applied to the dressing of muslin, would not have answered for lace; that the improvement was so great, that it was quite impossible that if any effectual means of doing the same thing had been discovered before, it should not have come into general use; that since that invention the lace manufactured in England was greatly improved, both in beauty and value; that the trade in the article had greatly increased, both at home and abroad; that a large proportion of the lace made, and all the better sort, was gassed; that, with the exception of an inferior description of lace, called warped lace, the lace exported was such as had been subjected to the patent process; that various experiments, made by men of science, for doing the same thing in other ways, had all failed.

As to the infringement:-That J. Boot had, some time back, Infringement. proposed to a bleacher to enter into partnership with him, stating that he had a gassing machine, but could not use it for fear of being discovered, but that if he had a bleaching establishment, he could, under cover of that, use it, sending a little lace to be gassed by the patentee, with whom he had an account; that his machine was exactly like the patentee's; that he had got one of Mr. Hall's men, that worked in the gas room, to introduce him into the room, and had then taken a plan of the machine, and had one made exactly on the same plan; that different parts of the machine had been made by different persons, and at a distance; that J. Boot had pointed out to the witness where the machine spoken of was; the situation of it, and the precautions taken for preventing its being seen; and

(b) The learned counsel then proceeded to state the nature of the evidence which he should adduce, to prove the infringement, and the novelty

of the invention. There was no doubt as to its utility.