if this principle is not new, the patent cannot be supported although it appear that the application of the principle, as described in the specification is new. This was decided in the case of Rex vs. Cutler, 1 Starkie's Rep.

354.

This was a scire facias brought to repeal letters patent, which had been granted for an invention claimed by the defendant.

It

The material question arising on the pleadings was whether the invention was new. appeared upon the defendant's specification that the invention consisted in a new mode of feeding the fire in a grate, by a supply of fuel from below, instead of from above, in the The coals intended to be con

usual way. sumed in the course of the day, were to be deposited in a chamber beneath the grate, so placed, that at first the higher surface of the chamber was to be on a level with the lower surface of the grate. The fire being afterwards lighted in the grate, as the coals in the grate were gradually consumed, their place was to be supplied by winding up the coals from the chamber by means of a rack and pinion. The coals, as long as they remained in the box, were unignited, the air being excluded from below, and did not become

ignited, until, by being wound up into the grate, they had been brought into contact with the coals previously ignited, and exposed to the access of the air.

The defendant, in his specification, had summed up the amount of his claim; stating, my invention consists in this, that the fuel necessary for supplying the fire shall be introduced at the lower part of the grate, in a perpendicular or in an oblique direction: as to the manner of performing it, it is set forth in the annexed descriptions and drawings."

In order to disprove the novelty of this invention, evidence was given that Mr. Marriott, a manufacturer of grates and stoves, had, in the year 1812, made a model (which was produced) of a grate, and its appendages for cooking. The grate, which was of considerable length, was furnished with a door; when this door was open the grate in no respect differed from an ordinary one, but when the door was shut, no part of the grate was visible, except a few of the highest bars, and the whole of the grate, having been filled with coals, and the coals within the bar above the door having been lighted, the coals in the lower part of the grate were carried up, for the purpose of supplying the consumption

above by means of a rack and pinion, at the discretion of the cook. The principle of this grate, it was contended, was precisely the same with that for which the patent was claimed: the lower part of the grate, when the door was shut, being in effect a closed chamber, to which the air had no access, and the coals being gradually wound up from this chamber so as to afford a supply to the fire above. Marriott stated that he had also applied the same principle to a common grate, long before the date of the patent.

Another manufacturer of the name of Coombe exhibited a grate for cooking, nearly on the same construction. The grate was supplied with two doors, one above the other; when both were shut, the air was supplied by a ventilator from below; when the lower door was shut, and also the ventilator, and higher door thrown open, the closed part of the grate supplied the place of a chamber, from which the coals were wound up by a rack and pinion, in order to supply the fire above, as it was wanted for culinary purposes.

It was contended for the defendant, that the invention went beyond that exhibited in these grates, in the latter there was no fresh introduction of fuel into the grates, so as to

give a perpetual supply, there was nothing more than a means of contracting or compressing coals already within the grate, which could not be done without diminishing the size of the grate itself. According to the defendant's construction, on the contrary, the chamber was independent of the grate, placed below it, and the fuel was gradually wound up from the chamber, without at all contracting the size of the grate itself. It was also contended that there were some minor advantages, which the patent grate possessed over those which had been exhibited in evidence.

Lord Ellenborough was of opinion that the principle on which the two grates were constructed was identical with that described in the terms of the specification, which was for a mode of supplying fuel from below, and there was nothing predicated in the specification of raising the fuel from below the grate, it was merely for elevating fuel from below, and that the defendant had confined himself, by thus summing up the extent of his invention to the benefit of this principle.Verdict for the Crown.

A patent may be sustained not only for "any new and useful art, machine, manufacture or composition of matter;" but likewise

for "any new and useful improvement on any art, machine, manufacture, or composition of matter."

Bull.

But the patent must not be more extensive than the invention, therefore if the invention N. P. 76. consists in an addition, or improvement only, and the patent is for the whole machine, it is void.

so that

In the case of Lowell vs. Lewis quoted in part ante p. 60, Story, Justice, observed that the patentee is bound to describe, in full and exact terms, in what his invention consists; and if it be an improvement only upon an existing machine, he should, distinguish what is new and what is old in his specification, it may clearly appear for what the patent is granted. The reason of this principle of law will be manifest upon the slightest examination. A patent is grantable only for a new and useful invention; and unless it be distinctly stated in what that invention specifically consists, it is impossible to say whether it ought to be patented or not; and it is equally difficult to know, whether the public infringe upon or violate the exclusive right secured by the patent. The patentee is clearly not entitled to include in his patent the exclusive use of any machinery already known; and if he does, his patent will be broader than his

I Mas.182.