(after stating the facts as above). [1] 1. Study of Carrier’s plan of operation (without naming it as a process or method) clearly differentiates the prior art relied on by defendants.1 In the patentee’s practice, air tempered (i. e., warmed if necessary) to 40°-45° F. is drawn from without a building into a spraying chamber, and there saturated (i. e., loaded with all the humidity it can carry) with or by means of water warm enough to raise the temperature to approximately 60° F. It then passes over or through an apparatus, usually of baffle-plates, which removes the free water particles carried by the air, and then passes a thermostat of predetermined range, by means of which if the temperature falls below an approximate 60° water of greater heat is provided, while a rise above said temperature will by thermostatic actuation cut off the hot water. By entirely separate heaters, the saturated air is further warmed (to say 70° F.) before passing into the room for which it is destined; such rise in temperature expands the air, and leaves any given cubic unit thereof with the prearranged relative humidity — because the vapor of saturation or dewpoint is distributed throughout whatever is the increased volume of a cubic unit of air saturated at (say) 60° F., and heated to (say) 70° F.
Thus what Carrier automatically controls is the temperature of saturation, upon which can be predicated with reasonable accuracy (i. e., “within limits”) the relative humidity of the air supplied to the room of destination. In so far as the few prior patents relate to anything more than machines for spraying or washing air, they depend on hygrometric control of and through humidity, not on thermostatic control through the temperature at which saturation is effected ; much less is there any prior showing of using a rise of temperature above that of saturation, to effect the desired relation of absolute and relative humidities. We agree with the court below that neither anticipation, nor close approximation, is discoverable in the prior art, so far as shown in this record.
[2] 2. Whether Carrier’s disclosed apparatus reveals invention is a question not before us — and immaterial. If the office had granted claims for both method and apparatus, that fact would not have vi*86tiated the patent (Steinmetz v. Allen, 192 U. S. 543, 24 Sup. Ct. 416, 48 L. Ed. 555), and, conversely, no more does the fact that it refused so to do, in the same patent at all events. Carrier had much the same experience in the office as the patentee in Jackson v. Birmingham, etc., Co., 79 Fed. at page 805, 25 C. C. A. 196, whose patent we sustained. No process patent is in theory either helped or harmed by the excellence or worthlessness of the disclosed apparatus by which it is illustrated.
[3] 3. As for infringement, it is uncontradicted that the heating and humidifying apparatus of these Buffalo schools was erected in accordance with specifications, which in our opinion might have been taken from Carrier’s application. We think it proven that defendants’ device operates on exactly the principle above summarized, and that, on every material point of difference asserted by defendants, the evidence in rebuttal is destructive. This question of fact is sufficiently elaborated in the opinion below.
[4, 5] 4. It cannot be doubted that Carrier discloses and claims a connected series of steps or operations for accomplishing a physical result, and this is often a fair definition of what is protected by a good process patent. Furthermore, he was the first to co-ordinate and. disclose this series of operations, and while his result, humidified air, was in a sense not new, air moistened by that method was a successful novelty. Therefore this patent is entitled to a construction as benevolent as that given by us to the desiccated milk process. Merrell, etc., Co. v. Powdered Milk Co. (D. C.) 215 Fed. 922, affirmed 222 Fed. 911, 138 C. C. A. 391.
We do not, however, resort to construction in aid of the claims in suit; for assuming now, as proved, an intelligible statement of process, novelty, and thought of the grade of invention, this patent presents acutely the problem stated by Justice Brown, in declaring that “it may be still regarded as an open question whether the patentability of processes extends beyond,” those involving “a chemical or other similar elemental action,” or can cover those necessarily -involving mechanical operations.2
This query has been answered, with a fullness sufficient for the purposes of this litigation, by Expanded Metal Co. v. Bradford, 214 U. S. 366, 29 Sup. Ct. 652, 53 L. Ed. 1034, holding that a process involving only mechanical operations might be within the protection of the statute.3
It is and always was true that the mere function or effect of the operation of a machine is not patentable; but, if a process be claimed *87as a patentable art, the inquiry is vital whether the important thing disclosed is the method of procedure, or the particular means by which it shall or may be practiced. Expanded Metal Case, 214 U. S. at page 381, 29 Sup. Ct. 652, 53 L. Ed. 1034.
If it is not reasonably possible to separate the alleged process from the disclosed means, the former can hardly be more than the function (or at least a function) of the latter. This is no more than applying the doctrine of Leeds v. Victor, etc., Co., 213 U. S. at page 318, 29 Sup. Ct. at page 500, 53 L. Ed. 805:
“A process and an apparatus by wliicti It is performed are distinct tilings. They may be found in one patent; they may be made the subject of different patents.”
If such difference cannot be discovered, they cannot be two things; therefore they must be one thing, i. e., one invention, and that one is usually the means.
[6] But that the means, and the only means of applying the process, are strictly mechanical, is a matter of no moment, so far as patent-ability is concerned. If the process, when distinguished from the means of performing it, is new, useful, and intellectually rises to the dignity of invention, it is patentable — if it falls within the meaning of the word “ail” as used in the statute.
The patent in suit responds to these tests, and this litigation affords an excellent illustration of their propriety.. If Carrier had and were suing on a patent for the apparatus pictured and described in his specification, it is very doubtful whether the humidifying plants of these Buffalo schools would infringe; mechanically there is, but little similarity. But the series of steps by which “within limits” dry cold air is transformed into an automatically steady stream of humid warm air are, in our judgment and that of the trial court, identical. Where this is the case, it is plain that means and process are separable, and the important thing is the process.
For the foregoing reasons, we agree that Carrier’s is a patentable and meritorious mechanical process, and direct that the decree appealed from be affirmed, with costs.
Bradford 222,234; Huck 476,274; Carrier 808,897; Cramer 813,083; Cramer 823,989.
Risdon, etc., Works v. Medart, 158 U. S. 68, 15 Sup. Ct. 745, 39 L. Ed. 899; Westinghouse v. Boyden, 170 U. S. 537, 18 Sup. Ct. 707, 42 L. Ed. 1136.
See comment on this case in Macomher’s Fixed Law of Patents (2d Ed.) p. 1011; and a full discussion of the effect of the Risdon and Westinghouse opinions in “Patentable Processes,” Harvard Law Review, vol. 19, p. 30. For a good illustration of how meritorious processes were fitted to the Risdon Case, before the Expanded Metal decision, see Cameron, etc., Co. v. Saratoga, 159 Fed. at pages 462, 463, 86 C. C. A. 483.