Opinion of the Court.

improvements and its disuse, show that the Hayes clamp never was anything more than an attempt to invent something which proved to be a failure.

"The question of fact, in this part of the case, must turn upon the character of the use of the lamp prior to September 16th, because it is established that the Hayes clamp and the Brush clamp, in its patented features, were substantially alike, and that the point in which they differ, viz., the length of the arms, is not a part of the principle of the device. Was the lamp with this clutch used merely to gratify curiosity, or for purposes of experiment, to see whether the feeding device was successful, or whether anything more was to be done to perfect it; or was it put to use in the ordinary business of the mill, as a thing which was completed, and was for use, and was neither upon trial nor for show?

"Hayes made the lamp for Wallace & Sons as an improvement upon the White lamp, and apparently turned it over to them to be used when they chose. An alteration was subsequently made in the location of the spring. The lamp was used at different times, in the work of the mill, at night, indoors, and out-of-doors. Its use at these times does not seem to have been for the purpose of testing the machine, or of calling attention to its qualities, or of gratifying curiosity, but it was used to furnish light to the workmen at their work. I have queried whether this use was not that of a thing which might be of help in an emergency, and which was thought to be better than nothing, though not of much advantage; but it was, apparently, used to accomplish the ordinary purposes of an electric light in a mill, to enable the workmen to see at night, although it was not uniformly used, because the mill was lighted by gas.

"But the plaintiffs press the question Why, then, was the further use of the Hayes clamp and lamp discontinued? This question is significant, because the abandonment of a thing which is greatly wanted is, ordinarily, a very suggestive circumstance to show that it was defective, and that, before the invention could be completed, something was to be done which never was done.

Opinion of the Court.

"I think that Wallace & Sons did not push the electric lamp business because they had no generator, and I also think that the Hayes lamp, either with or without the Hayes clutch, did not impress them favorably, for they contented themselves with making only one specimen, whereas they made six White lamps, and, after much experimenting, and after the invention of the Hayes lamp, they made fifty or sixty plate lamps. For some reason they did not manufacture the Hayes lamp, but turned away to the plate lamps. But the facts that the anticipatory device was the device of the patent, and did do practical work, and was put to ordinary use, and that it does not appear that the Hayes clamp was the cause of the neglect with which Wallace & Sons treated the Hayes lamp, seem to me to outweigh the doubts which arise from the shortness of its existence and its permanent disappearance from a carbon pencil lamp.

"The case is that of the public, well-known, practical use in ordinary work, with as much success as was reasonable to expect at that stage in the development of the mechanism belonging to electric arc lighting, of the exact invention which was subsequently made by the patentee; and, although only one clamp and one lamp were ever made, which were used together two and one-half months only, and the invention was then taken from the lamp and was not afterwards used with carbon pencils, it was an anticipation of the patented device, under the established rules upon the subject. With a strong disinclination to permit the remains of old experiments to destroy the pecuniary value of a patent for a useful and successful invention, and remembering that the defendants must assume a weighty burden of proof, I am of the opinion that the patentee's invention has been clearly proved to have been anticipated by that of Hayes. Coffin v. Ogden, 18 Wall. 120; Reed v. Cutter, 1 Story, 590; Pickering v. McCullough, 104 U. S. 310; Curtis on Patents, $$ 89-92.

"The bill, so far as it relates to the clamp patent, is dismissed."

We have examined carefully the evidence in this case, relied upon by the plaintiffs to show that the clamp arrangement of

Opinion of the Court.

Hayes was not a perfected invention, but was merely an abandoned experiment, and we have arrived at the conclusion that Judge Shipman's views on the subject are correct. They are well and accurately expressed, and we could not add to their force by a prolonged discussion of what is purely a question of fact.

The cases of Coffin v. Ogden and Pickering v. McCullough, cited by Judge Shipman, are enforced by the case of Hall v. Macneale, 107 U. S. 90, 97. This latter case meets, also, the objection made by the appellants that the mechanism of the Hayes clutch was concealed from view, and the further objection that it would not operate as perfectly as that of the Brush invention. In Hall v. Macneale, speaking of the anticipating safes, this court said: "The invention was complete in those safes. It was capable of producing the results sought to be accomplished, although not as thoroughly as with the use of welded steel and iron plates. The construction and arrangement and purpose and mode of operation and use of the bolts in the safes were necessarily known to the workmen who put them in. They were, it is true, hidden from view, after the safes were completed, and it required a destruction of the safes to bring them into view. But this was no concealment of them or use of them in secret. They had no more concealment than was inseparable from any legitimate use of them.”

It is contended by the appellants that, notwithstanding the prior existence of the Hayes apparatus as a perfected invention, claims 5 and 6 of the reissue are sustainable because each of them is limited to an "annular clamp." It is urged that the clamp of the patent is a ring which surrounds a cylindrical rod, and that the rod in the Hayes apparatus was square or rectangular, and was surrounded by a rectangular clamp. But it is quite apparent that claims 5 and 6 of the reissue would, if the patent were valid, be infringed by the manufacture and use of the patented apparatus with a rectangular carbon rod surrounded by a rectangular clamp. Such an apparatus might be inferior in perfection and utility to the cylindrical rod with the ring clamp; but it would still embody the principle of the

VOL. CXXXII-4

Statement of the Case.

invention, carried out by equivalent means.

The improvement, if any, in the use of the circular clamp over the rectangular clamp was only a question of degree, in the use of substantially the same means.

We are of opinion that the decree of the Circuit Court must be affirmed; and it is so ordered.

DENT. FERGUSON.

APPEAL FROM THE CIRCUIT COURT OF THE UNITED STATES FOR THE WESTERN DISTRICT OF TENNESSEE.

No. 32. Argued April 23, 24, 1889. - Decided October 28, 1889.

The petition of a bankrupt in bankruptcy, in which he states under oath that he owns no real estate and holds no interest in real property, is evidence of the execution and validity of a prior deed of his real estate in a suit in which he contests such execution and validity.

The proof in this case fails to show imbecility, dotage or loss of mental capacity on the part of the appellee at the time when the contract in dispute was made.

An executed agreement by one party to cause the debts of the other to be cancelled by his creditors, valid in its inception, is not invalidated as to the debtor by reason of the settlements being effected for a small percentage, or even by the employment of improper means to effect them. A conveyance by a debtor, deeply indebted, and in anticipation of decrees and judgments which, added to existing incumbrances, will amount to the value of the property conveyed, will lead a court of equity to presume that the instrument was executed in fraud of the creditors. If a person conveys his property for the purpose of hindering, delaying or defrauding his creditors, and for many years acquiesces and concurs in devices, collusive suits and impositions upon the court in furtherance of that purpose, without taking any step to annul such conveyance or stop such proceedings, a court of equity will not aid him or his heirs to recover the property from the grantee or his heirs after the fraud is accomplished.

The maxim "in pari delicto, potior est conditio defendentis" is decisive of this case.

THIS was a suit in equity originally brought in the Chancery Court of Shelby County, Tennessee, on the 10th of December,

Statement of the Case.

1881, by the appellees, heirs-at-law of Alexander M. Ferguson, deceased, against the appellants, heirs-at-law and legal representatives of Henry G. Dent, deceased. Upon application of the complainants, the case was removed into the United States Circuit Court for the Western District of Tennessee on the ground of the diverse citizenship of the parties.

The object of the original and the two amended and supplemental bills was to recover from the defendants a large amount of real property alleged to have belonged to A. M. Ferguson, deceased, and to have been fraudulently obtained from him by Henry G. Dent, deceased; and also to have set aside and annulled the agreement, deeds and judicial proceedings by which such fraudulent acquisition was effected.

The instrument which the complainants most especially sought to have delivered up and cancelled purported to be an absolute agreement and conveyance of a large amount of real property situated in Memphis, Tennessee, executed by Ferguson to Dent, and was as follows:

"This agreement, made this 14th day of May, 1869, by and between A. M. Ferguson, of the first part, and H. G. Dent, of the second part, all of the city of Memphis and State of Tennessee, witnesseth, that the said Ferguson, for the purposes and considerations hereinafter set forth, has this day bargained and sold to the said Dent all his right, title and interest of, in and to certain lots or parcels of land situated, lying and being in the city of Memphis and State of Tennessee, as per schedule thereof hereto annexed, and for identification signed by the parties hereto.

"That for said considerations he binds himself to make conveyance by quit-claim to said Dent, or to whomsoever he may direct, of said several pieces of property on demand, excepting, however, one piece of property contained in the schedule hereto annexed, situated on the southeast corner of Beale and Hernando streets, to which he agrees to make a warranty deed to James E. Dillard, to whom said Dent has bargained the same for $8000 subject to certain judgment liens which will be expressed on the face of said deed when it shall be executed. The