Subsequent to the filing of the opinion in this case, reported in 292 F. 571, the Aeheson Oildag Company presented a petition to this court for leave to intervene. It also prayed for a rehearing, on the ground that the patent of Abbott here in controversy was void, because its combination of a colloid, a penetrant, and a lubricant was anticipated by Aeheson’é patents, No. 966,636, of August 9, 1910, for a lubricant, and No. 1,030,-372, Of June 25, 1912, for a method of preparing dehydrated mixtures. It was further contended that our decision, if allowed to stand, might seriously affect the sale by the petitioner of its Aeheson oildag, although it was making such oildag under patents which antedated the Abbott patent here in suit. After argument and full consideration, we are not moved by either of these contentions.

By reference to qur opinion, it will be seen that in our view Abbott’s patent made a novel, useful, and patentable invention in the combination of a colloid, a lubricant, and a penetrant, whereby his mixture was able to enter, in a way those conversant with the art would not believe possible, between rusted, attached, and solidified metal surfaces, and allow them to be quickly and easily disengaged. The defendant, by using Aeheson’s oildag as a colloid,1 but adding thereto coal tar as a lubricant and a suitable penetrant, was also able to disengage solidified, rusted, adjacent metal parts in precisely the same way as Abbott. But the defendant dontended that its combination and practice had been already disdlosed in Acheson’s patent granted some 10 years before.

We cannot accede to this contention. A study of Acheson’s first patent shows that its disclosure was for a lubricant for lessening or avoiding friction, not between attached, solidified, metal surfaces, but between revolving parts. This Aeheson did by using deflocculated graphite and mixing with it light hydrocarbon oils, which, as he says, “do not for practical purposes possess lubricating qualities.” Aeheson’s problem dealt with interrevolving surfaces; Abbott’s, with interlocked surfaces. Aeheson’s aim was to prevent frictional engagement between moving working parts; Abbott’s was to allow temporary detachment between parts intended to be functionally locked against movement. Abbott’s problem. was analogous to unfastening a lock by a chemical substitute for a key; in other words, a chemical mixture was the force, instead of a wrench or a hammer and cold chisel. Aeheson’s problem was to ease contiguous revolving surfaces. The problems and spheres of the two inventors were different, and the solution of Acheson’s problem in 1909 threw no light on Abbott’s problem in 1916, and that Aeheson’s disclosure did not forestall is practically shown by the fact that, when Abbott disclosed his combination to the art, such art at first refused to use it, on the ground that it was an impossibility to affect rust-attached surfaces in the way Abbott disclosed. The novelty and originality, and indeed the pioneer character of Abbott’s disclosure, is evidenced by the fact *247he had to create a sphere and market for its use.

Finding Aeheson occupied a different field, and did not anticipate Abbott, it follows that Abbott’s later patent in no way interfered with the marketing of Acheson’s earlier disclosed oildag. The defendants did not buy such dag and sell it, but their infringing act consisted in mixing it as a colloid with a penetrant and lubricant to form the combination which Abbott disclosed. But, apart from the fact that the Aeheson Company is perfectly free to market their oildag, the plaintiff company tenders an acknowledgment of its right so to do.

In accordance with these views, the petition for rehearing and intervention is dismissed, at tho cost of the petitioner, and a mandate in the form already approved will go down to the court below for further procedure.