invented for a similar purpose. The plaintiff replies that it means all known mechanism of that sort. I will assume this to be its true limit in the intent of the plaintiff.

The question, after all, will be whether the plaintiff can hold the defendants as infringers of his invention. If he can, his claim is broad enough for that purpose. If he cannot, it is too broad..

What the plaintiff's invention was, so far as these claims are concerned, is not disputed. He added a pin or slot to the horizontal finger of the Greenhalgh loom, which adapted his light-balanced levers to operate like the heavy vibrating attachment of Greenhalgh, which, like the defendants' vibrating wheel and rod or rods, was pivoted at one side.

It is a presumption of law that all mechanics interested in. upholding or defeating a patent were fully acquainted with the state of their art when they took out their patent, or when they built their machine. This presumption is founded upon a policy like that which imputes to all persons charged with crime a knowledge of the law. It is necessary to the safe administration of justice. Each party may then be assumed to have borrowed from the other whatever was actually first invented and used by that other. So far as this case discloses the positive connection between the jack and the finger was first used by the defendants; but the horizontal position of the finger was not first used by the plaintiff. The only change made by the defendants in their actual from their patented machine is in this horizontal position; and this was not the plaintiff's property. This fact forbids the application of the formula of "known substitutes." That doctrine, first announced by Mr. Justice Clifford, and often applied by him, is that one who has invented and patented a new combination, however small and easy, if it be patentable at all, may treat as an infringement anything which is a purely colorable variation of his invention, obtained by substituting one well-known part or ingredient for another equally well known and fully understood by persons skilled in the art to be exchangeable in similar combinations for the part or ingredient which it replaces. It is a doctrine of very limited application, and, as a formula,

is, perhaps, rather misleading. The true question always is whether the defendant uses anything which the plaintiff in'vented.

In this case, the plaintiff first united the finger and jack when they were placed horizontally; but the defendants had already united them, for a similar use, when vertical. The whole emphasis, therefore, of the plaintiff's claim is on the word "horizontal." Now, whatever may be the advantages of this horizontal position in the defendants' jack and finger, and whether they took it from the plaintiff's patent or not, they may lawfully take it, because it was old at the time of the plaintiff's invention.

I cannot frame an argument which will sustain the broad claim of the plaintiff to a horizontal finger positively connected to a jack so as to aid its fall, which would not sustain a re-issue by the defendants, in which they should claim the positive connection, generally, between jacks and fingers, by which the finger should aid the jack to fall; and as the rights of the parties do not depend upon their skill and diligence in re-issuing their patents, but upon priority of invention, I cannot hold that there is any infringement of the plaintiff's invention. If there is any infringement of his claims they are void. Bill dismissed, with costs.

CROMPTON V. KNOWLES and others.

(Circuit Court, D. Massachusetts. April 18, 1881.)

1. PATENT-SHUTTLE-BOX MECHANISM FOR LOOMS-ALTERNATIVE DEVICE-PATENTABILITY.

Compound levers, with slot and pin connection to permit shifting of the fulcrum, being old, the substitution of a connecting rod for the slot and pin, held, to be a mere alternative device, and not patentable.

2. SAME-INFRINGEMENT" KNOWN SUBSTITUTE "-COLORABLE VARIA

TION.

The true test of infringement is the use by the defen lant of anything which the complainant has inventel, which includes mere colorable variations of his invention.

In Equity.

Causten Browne, for complainant.

Chauncey Smith and B. F. Thurston, for defendants.

LOWELL, C. J. The parties to this suit are the same as those in No. 308,* and the plaintiff, as in that suit, relies upon a patent which he has re-issued. In this case he complains that the defendants have adopted a compound lever to operate the drop-boxes or shuttle-boxes of their loom. These shuttle-boxes are required to assume different position, three, four, and so on, according to the number of colors which are wanted in the weft. The Knowles loom of 1863, referred to in the last case, contained two trains of mechanism, such as I there described, consisting of fingers and jacks, as one party called them, or extensible and contractible links, as they were termed by the other, which reciprocated up and down, under the influence of a pattern, and by gravity, to engage with constantly-rotating cylinders. In case 308 the motion given by the cylinders to the jack was used to move the levers which carried the heddles; in this case our attention is called to similar mechanism which is used to actuate a compound lever, through which the rod which holds the shuttle-boxes is shifted into several positions. In the patent of 1863 there were described two simple levers operating with a cord and pulley; and at the present time the defendants use, as I have said, a compound lever, which admits of a greater variety of motions than could be obtained by the two levers.

The complainant is the owner of the patent of Horace Wyman, dated in 1867, and re-issued in 1875, for an improvement in shuttle-box mechanisms for looms. The specification describes levers with movable fulcrums, or a compound lever, for imparting the necessary motion to the shuttle-boxes. In the drawing, six boxes are represented. Each lever has its connecting rod, which is actuated by a crank-pin mounted on a shaft having a toothed wheel. These wheels are connected with toothed racks, which slide back and forth under the impulse of pawls which are governed by a pattern. "Each crankpin can revolve from the upper center to the lower one inde*Ante, 199.

pendent of the motion of any other pin in the set, and when a pawl rocks a rocking arm the latter slides a ratchet-bar, and the ratchet-bar, through a toothed wheel, turns a crank-pin, and this pin, through the intervention of a connecting rod, shifts a lever."

The original patent claimed the mechanism generally. The re-issue has nine claims, of which the first, third and eighth are said to be infringed by the defendants.

"1. The combination of a lever, one end of which is connected to shuttle-boxes, with its actuating crank-pin and connecting rod, and another lever pivoted thereon, and the actuating crank-pin and connecting rod thereof, whereby four shuttle-boxes may be actuated; the combination being substantially such as described."

The second claim is less specific as to the number of boxes and more specific as to the combination of mechanism; claiming the levers and connecting rods, "in combination with two toothed wheels and two toothed surfaces, the toothed wheels turning the crank-pins, and the toothed surfaces moving the toothed wheels; the combination being substantially as herein set forth."

The eighth is for the combination where the lever has a shifting fulcrum, which has already been described as one form of compound lever.

The patentee says, speaking of compound levers: "Such levers are not new as applied to shuttle-box mechanism, and may be seen described in English and American letters patent prior to the date of my invention. My invention is therefore limited to certain mechanical devices in combination with such a lever or levers."

In his opening case the plaintiff put in evidence the English. patent of Whitesmith & Steven, published in 1860, which describes and illustrates in much detail modes of operating shuttle-boxes by means of levers co-operating with pawls and wheels; he draws one lever with a shifting fulcrum, and describes, shortly but intelligibly, the use of compound levers in this connection. These descriptions and drawings show the levers to be connected with the crank-pins of the actuating

wheels by a slot in one place and a pin in another, and this mode of connection is less vauable than that of a pitman or connecting rod to change the motion of the rotating wheel to that of the reciprocating lever. The experts differ upon the question whether the introduction of connecting rods by Wyman, supposing this to be all that he did, would make a new combination. This is the vital point of the case. Both experts agree that every mechanic knew, and for years had known, that a slot and pin and a connecting rod were alternative modes of obtaining this change of motion. If so, the change did not require invention.

The patentable differences, then, between the English contrivance and Wyman's are not in their levers or their connection with the crank-wheels. Wyman has combined with these parts double hooked pawls and sliding, reciprocating racks, to actuate the crank-wheels, instead of single toothed pawls and wheels constantly revolving in one direction. I suppose this to be a new combination in the sense of the law, and patentable; but it is so by virtue of the novelty of these parts.

It was suggested in argument that the Whitesmith & Steven loom may not have gone into use. I think the evidence on both sides is clear that it might have been used; and I have no doubt that it is one of the patents referred to by Wyman in his specification. One reason for this opinion is that Wyman is very careful in all three of the claims in issue to make the connecting rods a part of his combination. It is altogether probable that he thought the world at liberty to use levers with slots in all such combinations, and that he himself could hold all combinations which included connecting rods. In both points I consider him mistaken. He was not bound to limit his own particular combination in that way; and, on the other hand, he could not claim the Whitesmith & Steven machine as being his by adding connecting rods to it.

If the novelty of the plaintiff's combination consists in the mechanism to which I have above referred as differing from that of the earlier patent, it follows that he cannot complain that the defendants have combined Whitesmith & Steven's levers with their own pecular mechanism, invented by them before the date of Wyman's patent. In this case, as in No. 308,