delivered the opinion of the Court:
We think it will be apparent at once that appellant has made a meritorious invention, which marks a distinct and practical advance in the art. The action of the lower tribunals of the Patent Office allowing claims covering a specific embodiment of the settling chamber with reference to the stack amounts to a recognition that appellant has made a novel and useful discovery, while the decision of the Assistant Commissioner still more fully recognizes the scope and originality' of that discovery. In considering the references it is well to have in mind that appellant has accomplished the object in view, that is, the removal of nongaseous substances from the products of combustion, without the use of deflecting plates, water sprays, or other obstructions, without loss of heat from said products of combustion, and without impairing the normal draft of the stack. In other words, appellant’s chamber is so constructed and arranged that, independently of any other agency, it accomplishes this highly useful result. It goes without saying that the protection of an inventor should be equal to his invention, for otherwise he will not enjoy the reward which the law contemplates shall be his.
We now will briefly discuss the references relied upon by the Patent Office. The patent to Brett, No. 305,788, covers an “oxidizing and chloridizing furnace,” in which an entirely different problem confronted the inventor than that with which appellant dealt. In that patent the ore is fed into the stack and down through the heat and flame. The “dust chamber” there shown is merely an aid in saving all the elements of the ore. It really is 'an adjunct of the furnace. That no thought was given to draft, and that such a chamber erected in connec*531tion with an ordinary boiler would utterly fail to accomplish the object appellant had in mind, is apparent.
The patent to Van Horn, No. 1,012,301, covers a spark arrester, “designed especially for use in connection with locomotives.” The chief feature of that invention, according to the specification, “consists in providing a centrifugal separator arranged to give the exhaust gases one or more vertically disposed revolutions before the same reach the smokestack.” Between the means for providing these revolutions and the smokestack is a baffle plate. Van Horn was dealing with a locomotive engine, in which there is a forced draft, and he measurably accomplished the object he had in view by centrifugal force and a baffle plate. We fail to perceive that what he did in any way anticipated appellant’s work.
The British Patent to Dudley, No. 21,251, also covers a spark arrester for locomotive engines, operating under forced draft. What we have said concerning the Van Horn patent applies with equal force to this. t
Ve come now to the Worm patent. The apparent object of rule 15 is to require an applicant at least to make a prima facie showing of priority in order to overcome the references mentioned in the rulo. Certainly where an applicant substantially complies with the rule, his application should not be rejected summarily. In the present case, appellant states that prior to the date of the Worm application he explained his invention to the officials of the Baxitan Copper Works and attempted to have that company install it. While he did not state how long prior to the date in question he first approached that company, it sufficiently appears from the affidavit of Mr. Anti-sell that it could not have been earlier than 1910 or 1911. Appellant in his affidavit says that the construction which ho explained comprised the interposition of a large chamber between the boilers and a stack of such dimensions as to reduce the velocity of the products of combustion and effect a deposition of nongaseous particles without lessening appreciably the draft in the stack, and that in addition the chamber was to be constructed so as to conserve the heat of the gases therein. Mr. *532Antisell’s affidavit corroborates this statement, and we fail to perceive wherein the statement could have been more definite, unless the actual dimensions of the chamber had been given. Certainly it would have required no invention for any one measurably skilled to have installed the apparatus described by appellant. Nor do we think there is any failure to show diligence. Appellant was not concealing his discovery, but, on the contrary, diligently endeavoring to have it tested, and the only way it could be tested was by such an installation as actually took place. This was not a hand tool, but an idea, and its demonstration involved a large expenditure, much beyond the means of appellant. Of course, he might have filed an application, but, for the purposes of rule 7 5, we think his affidavit sufficient.
Moreover, even though the Worm patent be considered as a reference, what was said of the Brett patent would apply to this, for Worm’s object was to deflect and conserve particles of raw material.
As previously pointed- out, the Patent Office has awarded claims to appellant covering a chamber surrounding the stacic, but it has failed to protect appellant against a possible attempt to practise and appropriate his invention by placing the same kind of a chamber between the boiler and the stack. We are convinced that the reasons underlying the grant of the allowed claims require the allowance of another claim or claims which will more adequately protect appellant. In other words, since appellant’s invention resides in the discovery of a combination that will accomplish a definite result, he should be given claims sufficiently broad to prevent anyone from practising his invention by merely changing the position of the elements of the combination. We think claim 13, or a claim of equal breadth, should have been allowed. Throughout his specification appellant lays stress upon the importance of maintaining heat in the products of combustion and of constructing his chamber to that end, but a fair reading of his specification leaves no room for doubt that the desired result may be accomplished even though the chapiber is located outside the stack. Claim 13 *533covers the disclosures of the specification, and its allowance will more adequately protect this inventor.
The decision is reversed as to claim 13.
The following opinion, delivered by Mr. Justice Robb, February 17, 1917, was the result of a petition by the appellant for amplification of the former opinion of the Court:
This is a petition for amplification of our opinion in which we expressed the view that another count (No. 13), or claims, should be allowed petitioner for his more adequate protection. Thereafter petitioner, in addition to claim No. 13, asked the allowance in the Patent Office of a claim in which there is no limitation that the walls of the chamber shall be of nonheatconducting material. The Assistant Commissioner expressing the view that under our opinion he was not at liberty to consider such a claim, this petition was filed.
As pointed out in our opinion, this petitioner has made a meritorious invention and is entitled to adequate protection. If, in the view of the Commissioner, claim No. 13, in addition to those already allowed, will not afford such protection, we think that in the exercise of his discretion he may allow another claim or claims.