cKoita'iok ». k'nowEes. ���invented for a simil'a'r' plifpose. The' ^kintiff rephes tliit'ii ineans ali 1eno\ni meclianieifl: of tHaf 'sort. i will assunae t'his ���irror ���to be its true limit, in the inten|; of thp plaintiff. �The question, aiter aii, will be' whether' the plaintiff can hold the diefehdants as infringers of his invention. , If he can, his elaim is'broaa ehoiigh fbr'that purpose. If he cannot,,it is too broad. ' ' ' . ' \ ,. . �What the plaintiff 's invention wia,s', so far as these claims are concemecl, ie not dispiited. He ad.ded a pin or slot to the horizontal angef of the Greehhalgh loom, wtibh adapted iis light-balanced levers to opefate lik'e the heavy vibratihg a,i- tachment of Greenhalgh, which, like the defendants' vibrai- ing wheel and rpd or rods, was pivoied at pne side. �It is a prestimptioi) of iawthat all mechanics iiiterested in uphdlairig or cleieating a gatenl were iully acquainted i^ith thc state of their airt when they took oui tl^eir patent, or when they bailt their uiachifie. This presnmption js founded upon a poli(^;likethat which imprites. to all persons «hairged with crime a knowledge^of the law. It is necessaify to the safe ad- niihistration of justice. Each partj may then be assumea to have bdrrowed from the bther'whatever was actually firei invented and nsed by thai otiier. Sofar^ this case disclopes the positive connection between fhe jact and the finger wa» ffrst 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 ia'this horizontal pbsi'Eiod; itild "this was not the plaintifiE's prpperty. This fftcVftJrbJds the, application of the formula of "known substitutes." ,.That doctrine, first an- nioiiifced by Mr. Justice Clifford, and'of|^!ci|^pp!U^jai]py him^ is thaii que who hAs invented ^nd pAtented a new oomibination, how-ever small and easy, if it b&patehitable at all, aa^y treat as an jnfringemetit ahything whichlk a p'urely doldrable varfation of his invention, obtained by substituting one Tjrell-kno-wn part or ingredient for another equally well known and fully uader- stood (by persona skilled inithe art to be exchangeabie iia'simi- lar conibinations for the |Jart or iiieredient which it, replabes, It is a doctrine of very limit'ed application, ana, as a formula, ��� �
