The master found in favor of the plaintiff, this finding was confirmed by the court below, and a final decree entered for an injunction and an accounting.

The device of the defendant found to be an infringement is constructed in conformity with the patent issued to Vroom on May 1, 1906, No. 819,187.

A side elevation of the plaintiff's stacker is shown in figure 1. Figure 2 is a top or plan view.

In the specification of the plaintiff's patent the following passages are found:

"My invention relates to hay stackers, and particularly to that class in which the hay is placed upon a pivoted carrier, which is then raised to an upright position by means of an elevating frame.

"As heretofore constructed a great deal of power has been required to raise the carrier frame during the first part of the operation of raising it from its horizontal position, owing to the fact that in implements of this class horse power is generally used, and the system of levers used to change the direction of the pull has resulted in a loss of power through the decrease of leverage. "My invention has for its object to provide a stacker in which the power required will be more nearly uniform throughout the entire operation of raising the stacker from a horizontal to a vertical position and in which less power will be required. *

"By this means when the carrier frame is in a horizontal position almost a direct vertical pull is secured, which greatly diminishes the power required to lift the frame. * *

"By the peculiar arrangement of the lifting bars the direction in which the force is transmitted from the lifting rope 40 to the carrier frame is so regulated that during the first part of the lifting operation the power will be exerted almost at right angles to the carrier frame, and at the same time the power will be exerted upon the pulley 37 at about an angle of forty-five degrees, and it will therefore be very effective for lifting purposes.

"The most important feature of my invention consists of the use of two pivoted lifting levers arranged, as described, with their ends connected, whereby the power applied will be transmitted and applied to the carrier frame at an angle most favorable to secure the best results, at the same time providing for the application of such power to such lifting bars at a greater angle than has heretofore been possible in any construction known to me."

The claims here in question are 1, 2, 4, and 12, and they are as follows: "1. The combination with supporting devices, a carrying frame, and pivoted supports therefor, of pivoted lifting levers connected to each other at their

upper ends, one of said levers being connected to the carrying frame, and mechanism for operating said levers to lift the carrying frame, substantially as described.

"2. The combination with supporting devices, a carrying frame, and pivoted supports therefor, of lifting levers arranged at an angle to each other, the upper ends of said levers being connected, the upper end of one of said levers being connected to the carrying frame, and mechanism for operating said lifting levers, substantially as described."

"4. The combination with supporting devices, a carrying frame, and pivoted supports therefor, of a pivoted lifting lever 38 34, the upper end of which is connected to said carrying frame, lifting lever 35 36 pivoted at its lower end forward of the pivot of said lever 33 34, devices connecting the upper ends of said levers, and rope and pulley mechanism for operating said levers to lift the carrying frame, substantially as described."

"12. The combination with a runner frame, and an extensible and pivotally supported carrier frame, of lifting levers pivotally supported by the runner frame and connected together at their upper ends, devices connecting the upper end of one of said lifting levers to the carrier frame, and rope and pulley mechanism for operating said lifting levers to raise the carrier frame in the arc of a circle, substantially as described."

Although the defendant says in its brief that "the crux of the whole case is in the different derrick mechanisms used by complainant and defendant," yet it attacks the validity of the plaintiff's patent. Therefore it will be necessary to consider that question first.

On October 6, 1885, patent No. 327,852 was issued to Allen for an improvement in hay rickers and loaders. Prior to this time hay stackers had generally been constructed with a stationary upright frame. He was the first to introduce a hinged or pivoted lifting frame or lever, and to do away with the stationary upright frame. Hay stackers of various forms were presented after this date up to the time when the patent in suit was issued to Dain, who was the first to introduce two pivoted lifting frames or levers. That this was something new appears from the testimony of the defendant's expert. He said:

"In the Dain patent in suit the added element for the purpose of lifting the lifting frame 33 34 is a second lifting frame."

After referring to the various patents prior to Dain's, he said: "None of them have the precise lifting means called for by this claim” (1).

At another place he said:

"Dain having done nothing more than to add to the Allen construction an additional hoisting frame."

That he considered this addition to be an improvement appears. also from his testimony. He said:

"That is to say, the Allen stacker would stack hay, and would stack it in the same way that the Dain stacker stacks hay. There is only an improvement in the Dain invention in the manner of applying the power so as to get a more effective application of the power, but the thing done is the same."

He also said:

"It seems to me that in view of the Allen patent the invention in the Dain patent comes down to a very small feature."

After making these statements, he sums up his examination of the prior patents, as follows:

"As regards the subject-matter of claims 1, 2, 4, and 12, I would say that -I do not find any single patent in the prior art which has in it all of the

elements specified in these claims, except that as regards claims 1 and 2, the construction called for is found within the terms of these claims in the Boland patent, No. 366,617. I do find that everything called for by these claims 1, 2, 4, and 12 is found in the Blake patent, No. 433,067, as well as a number of others, with the exception of the particular lifting means, and this lifting means is clearly and fully disclosed in the British patents to McLaughlin & Maling."

He considered that the nearest American patents to the construction of claims 1, 2, 4, and 12 were those of Boland, No. 366,617, July 12, 1887, and Blake, No. 433,067, July 29, 1890, and of these he regarded the Blake construction as the closer. It is to be noticed in passing that, while he considers the Dain stacker as a mere improvement upon the Allen stacker, he does not consider the Allen patent the closest approximation to that of Dain. When he refers to the Blake patent as a close approximation to that of Dain, he is evidently referring to claims 6, 7, and 8 of the Dain patent, as appears from other parts of his testimony. The patent to Blake shows a high stationary frame, and only one swinging derrick or lifting frame. Of the patent to Boland defendant's expert says that "the same result is secured that is aimed at in the Dain patent" but he adds:

"The construction shown in the Boland patent is not the same as that shown and described in the Dain patent in suit."

As to this patent it is sufficient to say that we agree, as did the master, with the plaintiff's expert, when he said:

"Certainly to produce the stacker of the Dain patent in suit from the Boland device you would have to throw away about half of the elements of the Boland patent and radically rearrange and redesign the remaining elements, and such rearrangement and redesignment of the Boland structure would, in my opinion, call for a great deal of patentable invention."

We also agree with what the same expert further said with reference to this patent:

"It shows a combination of elements, some of which elements might have the same names applied to them as are applied to the elements of the Dain combination; but the combination in which these elements are employed in the Boland patent is radically different from the combination in which these elements are employed in the Dain patent. Inasmuch as the two combinations are so radically different, the fact the same names might be given to some of the elements per se of the combination makes no difference whatever as regards novelty of the Dain claims in view of the prior Boland patent."

Defendant claims, however, that although no one of the American patents shows the same lifting means as appear in the Dain patent, yet they are shown in the British patent to McLaughlin & Maling, No. 9,371, July 1, 1887. The defendant's expert considers this "a very close reference and rather better than anything that has been cited in the answer in this suit." It, however, was not discovered by any one until after the taking of the testimony in this action had commenced. The apparatus described in this patent is designed for raising heavy weights from the holds of ships or from mines. There is nothing in the specification to indicate that it can be used as a hay stacker. There are only two movements during its operation. The first is entirely vertical, the second is almost entirely horizontal, and