(after stating the facts as above). [1] The question of infringement need not detain us; it is admitted, if the rela-*858rive merits of Clay and Spengler were correctly adjudicated in the.trial court. The closure or stopper made under the Spengler patent utilizes the elasticity or resiliency of metal to produce a loose or tight fit over any aperature which, like a bottle mouth, has a flange surrounding the open end. A rude form of this operation can be observed when the well-known “Crown cork and seal,” having been carefully detached with a tool, is pressed down again over the bottle mquth, and malees a fairly close fit by the elasticity of its continuous rim.

But Spengler’s plan is to use the resiliency of the circular top1, and cause it to buckle or bend (either up or down, relative to the bottle) within such limits as not to disturb molecular formation, and in such wise that when the top is concave the fit over bottle mouth is loose, and when convex the rim bites closely the bottle flange. Pressure on rim produces convexity and locks the stopper, pressure on the resulting convexity spreads the rim and permits removal, and the process can be repeated indefinitely.

Claims 1 and 2 of Spengler were said by the examining authorities in the Patent Office to cover all patentable novelty in the application. We think they do, and No. 1, given below,1 is in the most general language, while Figure 2, also reproduced, shows the closure tightly covering bottle top.

This device is a most ingenious utilization of a familiar property of metal, its sim.'plicity is a high recommendation, and the fact that, once done,' it seems easy, is no evidence that inventive thought was not necessary to achieve it. While other patents are cited, we find no prior art except Clay, who, beside the patents in suit, obtained also Nos. 811,824 and 938,825 at dates prior to Spengler. We think it plain that Clay, while more frequently showing forms that would necessarily be expended by one use, did consistently utilize the resiliency of metal to obtain his closing or sealing force, and exhibited on paper some forms of stopper which he asserted could be used over and over again. It is rather singular that, of all the Clay patents, only 755,276 was cited against Spengler in the office, while in this litigation 755,275 is almost wholly relied on.

*859The claims of the Clay patents in suit are assuredly broad enough; No. 2 of 755,276 would plainly read on a replaced Crown cork and seal, while of No. 6 of 755, 275, given below,2 it is said arguendo:

“Tiie concaved center and the divided annular flange (made by radial slits) are so obviously present in the Spengler cap that no comment is necessary.”

Infringement is not so easily proved. To fit a patent claim on a product is only the first step. The next inquiry is: What was substantially described in the specification?

[2] Kxannning the whole line of Clay disclosures, we lay aside all forms expended by a single use, find on the evidence that the only stoppers shown or described in 755,276 that can affect Spengler are inoperative, and hold that the plan of operation most generally defined in the quoted claim from 755,275 is the only reference requiring mention. Below is shown Clay’s reusable stopper for “fruit or milk, cans,” as loosely placed on the top of a specially formed jar; when pressed down in the center the radially split rim, g, is said to engage the lip, d, and pressure on packing, h, resting on rib, b, seals the jar. (The “annular rib” of claim 6 is /.)

This apparatus fairly illustrates what were Clay’s theories of action, running all through his patents, in so far as they touch Spengler at all; i. e., he is trying to do away with elastic packing, on which Spengler depends. He uses the pushed-in or concave cover to produce closure, which is the antithesis of the means by which Spongier so simply produces closure and reusability on a common bottle, and he (in this instance ceriainly)' relies on buckling up and down (relative to bottle axis) to produce a pressure against a ledge (d) of a peculiar nature, which pressure, if effective at all, depends for its operation on the relative height of another ledge (b).

Clay did not first utilize or harness the buckling properties of nielal, nor did he claim so to do. He did try to apply them in the art of stopping bottles; but, giving the broadest possible scope to his somewhat doubtful and certainly unpractical disclosures, we agree with the court below that Spetigler’s idea of a “stopper clasping the neck of the bottle by buckling, and to be extracted by buckling in the reverse direction, was a new invention, and not a mere improvement upon Clay.” The decrees appealed from are affirmed, with one bill of costs.