Opinion of the Court.

or of something akin to genius, as distinguished from mere mechanical skill, draws one somewhat nearer to an appreciation of the true distinction, but it does not adequately express the idea. The truth is the word cannot be defined in such manner as to afford any substantial aid in determining whether a particular device involves an exercise of the inventive faculty or not. In a given case we may be able to say that there is present invention of a very high order. In another we can see that there is lacking that impalpable something which distinguishes invention from simple mechanical skill. Courts, adopting fixed principles as a guide, have by a process of exclusion determined that certain variations. in old devices do or do not involve invention; but whether the variation relied upon in a particular case is anything more than ordinary mechanical skill is a question which cannot be answered by applying the test of any general definition.

Counsel for the plaintiff in the case under consideration has argued most earnestly that the only practical test of invention is the effect of the device upon the useful arts-in other words, that utility is the sole test of invention, and, inferentially at least, that the utility of a device is conclusively proven by the extent to which it has gone into general use. He cited in this connection certain English cases which go far to support his contention. These cases, however, must not be construed in such way as to control the language of our statute, which limits the benefits of patent laws to things which are new as well as useful. By the common law of England, an importer — the person who introduced into the kingdom from any foreign country any useful manufacture was as much entitled to a monopoly as if he had invented it. Thus in Darcy v. Allin, Noy, 173, it is stated that "where any man, by his own charge and industry, or by his own wit or invention, doth bring any new trade into the realm, or any engine tending to the furtheránce of a trade that never was used before may grant to him a monopoly patent .. of the good that he doth bring by his invention to the commonwealth," citing several instances of skill imported from foreign countries. In Edgebury v. Stephens, 1 Webster's Pat. Cas. 35,

. the king in consideration

Opinion of the Court.

it was said: "The act [of monopolies] intended to encourage new devices useful to the kingdom, and whether learned by travel or by study it is the same thing."

It is evident that these principles have no application to the patent system of the United States, whose beneficence is strictly limited to the invention of what is new and useful, and that the English cases construing even their more recent acts, must be received with some qualification. That the extent to which a patented device has gone into use is an unsafe criterion even of its actual utility, is evident from the fact that the general introduction of manufactured articles is as often effected by extensive and judicious advertising, activity in putting the goods upon the market and large commissions to dealers, as by the intrinsic merit of the articles themselves. The popularity of a proprietary medicine, for instance, would be an unsafe criterion of its real value, since it is a notorious fact that the extent to which such preparations are sold is very largely dependent upon the liberality with which they are advertised, and the attractive manner in which they are put up and exposed to the eye of the purchaser. If the generality of sales were made the test of patentability, it would result that a person by securing a patent upon some trifling variation from previously known methods might, by energy in pushing sales or by superiority in finishing or decorating his goods, drive competitors out of the market and secure a practical monopoly, without in fact having made the slightest contribution of value to the useful arts. The very case under consideration is not barren of testimony that the great success of the McClain pads and clasping hooks, a large demand for which seems to have arisen and increased year by year, is due, partly at least, to the fact that he was the only one who made the manufacture of sweat pads a specialty, that he made them of a superior quality, advertised them in the most extensite and attractive manner, and adopted means of pushing them upon the market, and thereby largely increased the extent of their sales. Indeed it is impossible from this testimony to say how far the large sales of these pads is due to their superiority to others, or to the energy with which they were forced upon the market.

Syllabus.

While this court has held in a number of cases, even so late as Magowan v. The New York Belting and Packing Co. ante, 332, decided at the present term, that in a doubtful case the fact that a patented article had gone into general use is evidence of its utility, it is not conclusive even of that—much less of its patentable novelty.

In no view that we have been able to take of the case can we sustain the second McClain patent. We do not care to inquire how far it was anticipated by the various devices put in evidence, showing the use of a similar spring for analogous purposes, since we are satisfied that a mere severance of the double spring does not involve invention, at least in the absence of conclusive evidence that the single spring performs some new and important function not performed by it in the prior patent. The evidence upon this point is far from satisfactory, and the decree of the Circuit Court must, therefore, be

Affirmed.

The CHIEF JUSTICE and MR. JUSTICE GRAY did not hear the argument and took no part in the decision of this case.

MCLEAN v. CLAPP.

APPEAL FROM THE CIRCUIT COURT OF THE UNITED STATES FOR THE NORTHERN DISTRICT OF ILLINOIS.

No. 31. Argued October 15, 16, 1891.- Decided November 2, 1891.

Grymes v. Sanders, 93 U. S. 55, affirmed and applied to the point that where a party desires to rescind a contract upon the ground of mistake or fraud, he must, upon discovery of the facts, at once announce his purpose and adhere to it, and that if he be silent, and continue to treat the property as his own, he will be held to have waived the objection, and will be conclusively bound by the contract, as if the mistake or fraud had not occurred.

A holder of the legal title to real estate who has no equitable interest therein, cannot, by his act done without the knowledge or consent of the holder of the equitable title, who is in possession of and residing on the premises claiming title, rescind a completed settlement of a mortgage

Opinion of the Court.

debt on the premises so as to bind the holder of the equitable title, and prevent him from setting up defences which would otherwise be open to him.

IN

EQUITY. Decree dismissing the bill. The plaintiffs appealed. The case is stated in the opinion.

Mr. Edwin B. Smith for appellants.

Mr. Solomon H. Bethea and Mr. Sherwood Dixon for appellees.

MR. JUSTICE BREWER delivered the opinion of the court.

In December, 1855, Edwin W. McLean, owning a store and stock of goods in Amboy, Illinois, sold the same to Ruggles W. Clapp, in payment for which he received four notes, amounting in the aggregate to five thousand nine hundred and eighteen and sixty-six one-hundredths dollars, drawing ten per cent interest, and secured by mortgage on four hundred and eighty acres of land. The first of these notes, for five hundred dollars, due in twenty-five days, was paid; the others were not. The last of the notes became due in May, 1857. Soon thereafter suit was commenced in the state court on them, and to foreclose the mortgage. In this suit the defence of usury was pleaded. A settlement was made with Clapp, in pursuance of which the three unpaid notes were surrendered; and in lieu thereof there was taken a draft for one thousand dollars, drawn on his brother, Alfred Clapp, of New York City; and eleven notes, five for two hundred dollars each, dated June 10, 1857, made by William Jones to Ruggles W. Clapp, three made by Cyrus Craig, November 29, 1856, to Ruggles W. Clapp, two for one thousand dollars each and one for fourteen hundred dollars; and three made by Curtis Cannon, August 1, 1857, to Ruggles W. Clapp, for four hundred and thirty-three and thirty-three one-hundredths dollars each. These notes were all endorsed "without recourse," and were nominally, at least, secured by conveyances of real Also, to secure the draft, on which only $250 was ever paid, a conveyance was made of a lot and building in the

estate.

Opinion of the Court.

town of Amboy. There was no formal release of the mortgage; but the suit to foreclose was dismissed. This settlement was consummated some time in the latter part of 1857, or the fore part of 1858; and was consummated on the part of McLean by W. E. Ives, his attorney at Amboy, McLean himself having moved after the sale of the store to Great Barrington, Massachusetts, though it is claimed by the defendants. that the terms of the settlement were agreed upon between McLean and Clapp in the summer of 1857, when McLean was on a visit to Amboy. In the summer of 1861 McLean, dissatisfied with the conduct of Ives as his attorney, discharged him and placed his business in the hands of one M. L. Arnold. While Arnold testified that in the same summer he notified Clapp that McLean repudiated the settlement, nothing was in fact done looking toward a repudiation until May, 1872, when this suit was commenced in the Circuit Court of the United States, by McLean, to set aside the settlement, and foreclose the mortgage, as though it still remained security for the original notes. Answers were filed, and some preliminary steps taken in the case during one year, and up to May, 1873. From that time no order was made or proceedings had in the case until July, 1882, when it was dismissed for want of prosecution. In the November following the order of dismissal was set aside and the case reinstated, and leave given to file a bill of revivor in the name of the widow and heirs of McLean, who had died in 1875. The case thereafter proceeded regularly till May, 1887, when, upon final hearing, the bill was dismissed.

The contentions of defendants are substantially-first, that McLean himself arranged the terms of the settlement of 1857; that he did this understandingly and without any fraud or misrepresentations on the part of Clapp, and hence cannot now repudiate it; secondly, that if he did not himself arrange such terms, he was in 1861 fully informed of the character and value of the paper and securities received by his agent in the settlement, and that with such full information he thereafter acquiesced in and ratified it; and, thirdly, that his laches and delay in asserting his rights forbid any recovery against