(after stating the facts as above).
We refer thus fully to this Hayde patent to indicate its scope, and what was in fact claimed for it, and to preface the statement that nowhere in Hayde’s specification or claims is there reference to an expanded or porous product, or one which would result in a materially lighter aggregate for concrete than the ordinary gravel, sand, and crushed rock aggregate.
In the Patent Office this Hayde patent, earlier than Olsen in application and grant, was cited against Olsen; whereupon Olsen amended certain of his claims to emphasize that the burning of his process did not produce the product of “hard dense particles and clinkers,” as stated in the Hayde specification, and in his claims 1, 3, and 5 Olsen substituted the words “burned but not clinkered,” and in claim 2 “burning-without elinkering”; and as thus amended his claims were allowed.
When Hayde sought a reissue, and undertook to make claims for an expanded cellular aggregate, such claims were denied him on the ground that he had not originally described any such article.
*868But it is contended that before the Olsen invention Hayde had reduced to practice a process substantially like that of the Olsen patent, and had made a concrete aggregate and a concrete substantially like that described and claimed in Olsen’s patent.
Olsen and Hayde had been long acquainted, and had had some business relations. Both had been working in-the art of making concrete. As far back as October, 1905, Hayde had secured patent No. 803,285, for “fire and water proofing composition,” of which coarse and powdered burned clay were constituent parts of a concrete product. It seems that some time afterward Olsen proposed getting a license under this patent, for the making of telephone poles and the like..
The evidence justifies the conclusion that for several years prior to the application for his first above patent Hayde was actively experimenting for the production of a lightweight aggregate as a constituent of molded brick and other concrete articles. In the early stages of the World War there was discussion and investigation respecting the feasibility of employing concrete in building ships and barges, and it was evident that a light weight concrete, .otherwise adaptable, might be of much value for such use. It was abundantly shown that at least as far back as early 1917 Hayde had submitted samples of various such products from burned shale to.laboratories for testing, and that the tests showed the aggregate, as well as the concrete made from it, to be expanded and porous and about 30 per cent, lighter than concrete aggregates ordinarily were.
The commercial aggregate put out by the Hayde interests was' called “Haydite,” and while it was asserted to be made under Hayde patent, No. 1,255,878, it was put out under the claim that it possessed, inter alia, the virtue of lightness. Early in' 1918 it was submitted to the Bureau of Standards at Washington, and in some of the reports of the Bureau of about that time it was stated that “Haydite” was one of the products submitted for “tests of - various aggregates to produce a light strong concrete.” In a Bureau sheet of May, 1918, it was said:
“In order to produce a concrete that weighed considerably less than concrete as ordinarily made tests have been made of a large Variety of aggregates, including * * * Haydite, a shale or clay clinker.”
Various other of the Bureau reports showed Haydite to be much lighter than ordinary concrete aggregates and products.
On this subject the District Court said:
“The evidence shows that Stephen J. Hayde in 1915 had a burned, light-weight, expanded material which he sent from California to his nephew George Hayde in Kansas City. The letter to his nephew concerning the material directs special attention to the light-weight characteristic of the burned material. The evidence further shows that from March to September, 1917, Hayde submitted samples of burned aggregate to the Kansas City Laboratory for testing. !Pour of the nineteen samples submitted were of such exceptional lightness that Dr. Cross, the chemist in charge of the laboratory, noted the fact on the test sheet, though he says Mr. Hayde did not seem particularly interested in the fact and had requested no tests for weight. Dr. Cross, who is now a stockholder in the complainant’s company, states, however, that there is no doubt but that Hayde ‘had a light-weight aggregate.’ The foregoing evidence, together with the tests made on Hayde’s material by the United States Shipping Board, the material introduced in evidence which was sent to Prof. Duff A. Abrams for testing in the laboratory at Lewis Institute .during April and May,-1917, and the mass of evidence which may be taken as highly corroborative, to the effect that Hayde had been experimenting constantly for several years prior to 1918 to perfect a method of producing a satisfactory light-weight aggregate, burned from clay and shale, often with excellent restilts, shows conclusively to my mind that Hayde had conceived and produced a light-weight aggregate such as Olsen claims before Olsen conceived or produced it.”
We are in accord with this view of the court, notwithstanding the strange fact that in the application for patent No. 1,255,878 Hayde made no reference whatever to a product materially lighter than concrete aggregates theretofore ordinarily in use.
The question here is the status of the Olsen patent and appellees’ alleged infringement of it. The court found that Olsen’s invention did not antedate his application, which was filed May 22, 1918. In this we must concur. The fact that Olsen died so soon after his patent issued may be deplorable, but does not raise unusual .or extraordinary presumptions in favor of an earlier date. Practically all that is relied upon to carry back his invention date is the fact that on a laboratory test sheet of his material dated May 29, 1918, there is a notation in Olsen’s handwriting that the sample covered by *869the sheet had been in salt water for fourteen months. This is merely a declaration by Olsen in his own interest and cannot serve to carry back his invention date unless there is corroboration of the truth of what is noted. Of this there is no corroboration whatever. It must be remembered that these occurrences were at a time when there was public demand for a light, strong, and tough concrete for shipbuilding, and there would be strong incentive, on the part of inventors working in this field to date their discoveries far enough back to anticipate others. While this incentive or interest was present with Hayde not less than with Olsen, it happens that in Hayde’s case there is strong corroboration, which in Olsen seems to be wholly absent.
As to the process employed by appellees, it is contended that it is materially different from that of the Olsen patent. The court found that in several respects this was true. The process or method pointed out in the Olsen patent is decidedly meager, but it must not for that reason be accorded application broader or more inclusive than if it were more definitely indicated.
All that is revealed by Olsen on the important subject of burning the rock is that he subjects it “to a temperature of 2000 degrees Fahrenheit or above for a period determined by the nature of the rock, so that all organic matter therein is destroyed and it is reduced to a light porous, hard material”; whereas, the evidence shows that in appellees’ process the crushed shale enters the kiln at 600 degrees, remaining at that temperature for a considerable time until it has passed along about thirty feet of the kiln, and when about ten feet from the discharging end it is subjected to a high temperature for'a very short time. When a process patent discloses that the temperature and the time of exposure thereto is an important and distinguishing element of the process, a departure therefrom will, in general, be a departure from the process of the patent.
Claims 4, 6,10, and 11 have no reference to the manner of burning the shale, and from them it could not remotely be deduced that a porous light-weight aggregate, or a process for making it, or a concrete incorporating it, is the subject-matter of those claims. For any limitation appearing therein to the contrary, the material, product, and process referred to may be substantially the same as in both of Hayde’s earlier patents, if, indeed, not disclosed by other earlier patents, such as No. 930,801, August, 1909, to Senn and Kluger, and British patent No. 4,834 of 1882 to Paterson and Scott.
We are of opinion that claims 4, 6, 10, and 11 are not valid, and we agree with the District Court that the evidence does not show that appellees infringed claims 1, 2, 3, and 5.
The decree of the District Court is affirmed.