and sufficiently explicit for the compound composed of nitro-glycerine and the inexplosive porous substance mentioned, and the claim was only for a composition of matter made of the ingredients, in the manner, and for the purposes described in them. There was therefore nothing to correct in a reissue, according to the decision in Russell v. Dodge (3 Otto, 463). The claim was as extensive as the invention specified, and there is no pretense that this was not sufficient to cover a compound of nitro-glycerine with inexplosive porous absorbents.

The case might be rested here, but respect for the able and distinguished judges of the first and second circuits requires some notice of their decisions. They have held that the reissued patent is valid, against a defense that it covers a different invention from that described in the original patent, and that the term "inexplosive" in the original specifications is used only in a relative sense as compared with nitro-glycerine, and not in an absolute sense excluding the entire use of all explosive absorbents, whatever their degree of explosiveness. Their attention does not, however, appear to have been directed to the point that if the original patent was valid and operative with the existing specifications there was no case for a reissue for the consideration of the Commissioner. On the contrary, their opinions, like the argument of counsel in the case, go to show that the original patent was valid and operative, and that its specifications were sufficiently comprehensive to include explosive absorbents, if the resulting compound could be safely used, stored, and transported. If their positions be sound, there was no ground for a reissue, and the new letters cannot be sustained. But, independently of this consideration, we are not able to concur with the learned judges as to their interpretation of the term "inexplosive" in the original patent, and consequent judgment that the reissued patent is for the same invention. While we cannot look outside of the patent for the explanation of terms in it which are not technical and are free from ambiguity, we can examine into the history of the invention patented so as to be able to read the specifications in the light of the inventor's knowledge. We can place ourselves in his position so as to see, as it were, with his eyes and speak with his language. The natural signification of the term "inexplosive" would exclude explosive absorbents, and where an attempt is made to qualify and limit this meaning, we are at liberty to inquire into the circum. stances under which the term was used. It was held by the supreme court of California, in construing an agreement concerning the boundaryline of mining claims, where the term "North" was used, that it was competent to show by the usage of the place that it had reference to the line indicated by the compass there, and not to a line due north according to the true meridian. Jenny Lind v. Bower, 11 Cal., 194.

Now, reading the history of the labors of Alfred Nobel to utilize the explosive power of nitro-glycerine and render it safe to transport, handle, and use-the experiments he tried, first, to explode the nitroglycerine in mass; then, in consequence of the dangers attending its

use, to prevent its explosion when handled; the patents he obtained in Europe; his experience in the use of gunpowder and other explosives with nitro-glycerine-it is impossible to believe that he intended anything different from the natural meaning of the term he used. He knew well the danger attending the use of nitro-glycerine with explosive absorbents, and in limiting his claim to its use with inexplosive absorbents we must presume that he at that time intended to abandon all claim to compounds of a different character, or at least to leave such claim open for further consideration. If we read his own language in an application made three years afterward for a new patent for a compound with explosive absorbents presented to the Commissioner of Patents by the complainant, and therefore adopted and approved by it, there can be but little doubt on the subject. Soon after the new patent was obtained the application for a reissue was made, evidently that it might reach back to the date of the original patent and cover inventions of other parties during the intermediate period, or that which had gone into public use.

We do not attach to the general language used by Nobel in the first patent, following the statement of the nature of his invention, the significance ascribed to it by counsel. We give it a different construction. The statement is that

The nature of the invention consists in forming out of two ingredients long known -viz: the explosive substance nitro-glycerine and an inexplosive porous substance, hereinafter specified-a composition which, without losing the great explosive power of nitro-glycerine, is very much altered as to its explosive and other properties, being far more safe and convenient for transportation, storage, and use than nitro-glyceriue. Following this statement is this language:

In general terms my invention consists in mixing with nitro-glycerine a substance which possesses a very great absorbent capacity, and which at the same time is free from any quality which will decompose, destroy, or injure the nitro-glycerine or its explosiveness.

The substance here mentioned as possessing a great absorbent capacity has reference not to any absorbent substance, but that which is specifically designated in the preceding statement of the ingredients of the compound, as if the inventor had said:

In general terms my invention cousists in mixing with nitro-glycerine a substance which possesses a very great absorbent capacity, which substance is porous and inexplosive, and is hereinafter specified.

The inexplosive porous substances, afterward specified, were certain kinds of silicious earth or silicic acid, known under the general term of "silicious marl," tripoli, rotten-stone, and the like, the best of which was composed of the remains of infusoria.

This construction renders it unnecessary to give a forced meaning to the term "inexplosive," and is consistent with all the preceding and subsequent statements and conduct of the inventor, as disclosed in the history of his invention. It nowhere appears that he had any knowledge

or belief when the first patent was issued that the admixture of nitroglycerine with explosive substances would produce a safety-powder. That was a discovery which he did not make or claim to have made. So when in his specifications he mentions charcoal as an absorbent, he observes that it has the "defect of being itself a combustible material." To our mind, looking at the history of the invention and reading the specification of the patent in its light, it is clear that the inventor used the word "inexplosive" in its natural and ordinary sense, and that the attempt to limit that meaning is an afterthought of his assignees, desiring to bring within the reach of the patent compounds in no respect within his contemplation. In other words, the reissued letters cover a compound not claimed by Nobel and not embraced in the original patent It follows that, in our judgment, the complainant has no just cause of complaint against the defendants, and its suit must be dismissed with costs; and it is so ordered.

[Supreme Court of the United States.]

BALL ET AL. v. LANGLES ET AL.

Decided November 15, 1880.

18 O. G., 1405.

1. Reissued Letters Patent No. 4,026, granted to Hosea Ball, June 14, 1870, for an improvement in ovens, declared to be invalid, it being for a different invention from that covered by the original patent.

2. The Commissioner of Patents is invested by law with authority to determine whether surrendered patents are invalid by reason of defective or insufficient specifications or by reason of the patentee's claiming as his own invention or discovery more than he had a right to claim as new, and whether these errors have arisen by inadvertence, accident, or mistake, and without fraudulent intention. His decision as to the existence of these prerequisites is conclusive, and not subject to review by the courts.

3. The Commissioner, however, has no authority to grant a reissue embracing new matter or a broader invention than what was revealed in the original specifications, drawings, or models.

4. The question of identity of invention is to be determined by an inspection of the two instruments.

5. Where an original patent described an interior baking-chamber as provided with perforations in its sides and back, whereby its interior had communication with the fire-space only indirectly through sides and back flues, Held, that a reissue removing the restriction as to the location of the perforations, so that the interior of the chamber may communicate directly or indirectly with the fire-space, is void for containing a different invention.

APPEAL from the circuit court of the United States for the district of Louisiana.

Mr. T. J. Durant for the appellants.

Mr. Leigh Robinson and Mr. Conway Robinson for the appellees.

Mr. Justice STRONG delivered the opinion of the court:

The bill charges an infringement of reissued letters patent for an

alleged new and useful improvement in ovens, granted Hosea Ball on the 14th day of June, 1870. The original patent was granted to Ball on the 25th day of September, 1856, for a period of fourteen years from that date. On the 12th of October, 1869, this original was surrendered and a reissue was granted. A second reissue was granted on the 14th of June, 1870, numbered 4,026. Subsequently an extension of the patent was granted for seven years from September 23, 1870. It is upon the second reissue, No. 4,026, thus extended, that this suit is founded. The charge of the bill is that the defendants have constructed such an oven as that patented with intent to use it. The circuit court dismissed the bill, and from that decree the complainants have appealed.

The first question now to be considered under the pleadings and evidence is whether the reissued Patent No. 4,026 is valid. One of the defenses set up by the answer is that the reissue is not for the same invention as that described, claimed, and shown in the original letters, and it is averred that the surrender of those letters and the first reissue were for the purpose of introducing new matter not shown, suggested, or indicated in the specification, drawings, or model filed with the orig. inal application, and also for the purpose of obtaining a claim broader than the invention and broad enough to cover the invention of subsequent inventors and patentees. If these averments of the answer are well founded, the reissue is void, and it will be unnecessary to consider the other defenses set up.

When the reissues of 1869 and 1870 were granted the Commissioner of Patents had authority under the acts of Congress to grant reissues only in certain specified cases. These were whenever a patent was inoperative or invalid by reason of a defective or insufficient specification, or by reason of the patentee's claiming as his own invention or discovery more than he had a right to claim as new if the error had arisen by inadvertence, accident, or mistake, without any fraudulent or deceptive intention. The Commissioner was invested with authority to deter mine whether the surrendered patent was valid by reason of a defective or insufficient specification or because the patentee had claimed more than he had a right to claim as new, and if he found such to be the case, and found also that the error had been due to inadvertence, accident, or mistake, without fraud, his decision was conclusive and not subject to review by the courts; but the law did not confer upon him jurisdiction to grant a reissue embracing new matter or a broader invention than what was revealed by his original specification, or drawings, or models, except in some cases where there was neither model nor drawing. A reissue for anything more is therefore inoperative and void. Accordingly this court has repeatedly held that if, on comparing a reissue with its original, the former appears on its face to be for a different invention from that described or indicated in the latter, it must be declared invalid. Seymour v. Osborn, 11 Wall., 544; Russell v. Dodge, 93 U. S., 461.

In the original patent Ball described his invention as consisting of an

oven with a series of bread-receivers swung between the ends of a rod hung in an interior perforated chamber and capable of rotation on a horizontal shaft, an arrangement being provided for the self-delivery of the bread from the front of the oven, as afterward set forth. Having thus described it generally, he proceeded to set forth in detail its construction, including the mode in which it was heated. This was done in part by explanation of his drawings. A fire-chamber was represented below the oven with an ash-pit beneath. Above the fire chamber, but beneath the oven, a space through which the products of combustion passed on their way to the chimney, communicating by openings with vertical side and back flues. These flues were exterior to the oven proper, but they communicated with the interior chamber or oven by perforations or openings. In this interior chamber the bread was placed on platforms hung on a revolving rod, and a mode of discharge and filling was described. The specification then stated that, "owing to the perforated sides and back of the interior chamber, all parts of it receive the full heat of the oven, suitable dampers regulating the course of the products of combustion to the chimney." Such was the description, so far as it is necessary to state it. The single claim of the patent was us follows:

What I claim, and desire to secure by letters patent, is—

The perforated interior chamber, in combination with the rotary wheel and the swinging platform thereon, self-discharging, substantially as set forth.

It is evident from this description and from the attendant drawings that the interior chamber or oven was so constructed that what are called "the products of combustion" did not and could not pass directly into it. The chamber was heated by those products passing through the exterior flues on the sides and back. There was no direct communication between the space above the fire-chamber and the interior of the oven, and no communication at all except indirectly through the perforations in the vertical flues on the sides and back of the oven. The interior chamber was heated for baking by heat radiating from its walls, except the comparatively small quantity which was permitted to enter through the small perforations in the flues. It is impossible to detect in the specification or drawings any intention or hint even of conducting the products of combustion (whatever may have been meant by the phrase, whether heat, gases, or smoke, or all of them) directly into the bakingchamber. Not a single ray of heat could enter the chamber, radiated from the fire. No passage was provided through the bottom, and even the perforations in the sides must have been ineffectual to divert the ascending heat from its upward course through the flues.

If, now, we turn to the reissues of 1869 and 1870, it cannot be doubtea that while they claim what was claimed in the original they claim much more. They claim an entirely different mode of heating the chamber, necessitating a radical difference in the construction of the oven.

The specification of the reissue of 1870, as well as that of 1869, instead of representing the space above the fire-chamber as communicating with