616 THE POPULAR SCIENCE MONTHLY. 



tinguished from the old one ; or, in the sense of the patent law, can 

 entitle the manufacturer to a patent." 



So much for the negative method of investigation of the subject of 

 novelty in patents. We have discussed many cases of apparent nov- 

 elty and have seen in what novelty does not consist. In accordance 

 with the old saw, "You tell me what you're not, and I'll tell you what 

 you are," we are now prepared to turn to what I have called the posi- 

 tive method of investigation and learn what is patentable novelty. 



To answer the question, What is novel, so as to be patentable ? 

 is easier than the one we discussed in the first part of this paper. In 

 a few words, there is patentable novelty when there is a different prin- 

 ciple of operation ; when there is a different result in kind, or when 

 there is a new combination. It is for one or another of these reasons 

 that a patent is ever granted. There may be other grounds apparent- 

 ly, but a closer investigation will show them to be but another species 

 of the above family, and consequently to be classified with them in 

 their application. 



The first two of the three principles enumerated can best be treated 

 of together. To repeat, there will be novelty when either the manu- 

 facture produced, or the manner of producing an old one is new. In 

 the former case there must be something substantially new, different 

 from what was before known. In the latter case the principle of the 

 machine must be different. And, as I have shown before, a mere 

 change of the form or proportions will not suffice, if both are the same 

 in principle, structure, mode of operation, and produce the same re- 

 sult. This is true even if there is some small variance in some small 

 matter for the purpose of evasion, or a color for a patent. There 

 must be some principles different from any previously known. 



This opens up the ancillary and important question, What is meant 

 by " the principles of a machine " ? 



In Whittemore vs. Cutter, 1 Gall., 478, Judge Story says : " By the 

 principles of a machine is not meant the original elementary principles 

 of motion which philosophy and science have discovered, but the 

 modus operandi, the peculiar manner or device for producing any 

 given effect. If the same effects are produced by two machines by 

 the same mode of operation, the principles of each are the same. If 

 the same effects are produced, but by combinations of machinery oper- 

 ating substantially in a different manner, the principles are different." 



In deciding whether the principles of a machine are new, there is 

 one block over which we may stumble and which we should take care 

 to avoid. There is danger of confusing form with principle. The 

 question of what constitutes form and what principle is frequently a 

 very nice question to decide. Judge Washington, in Treadwell vs. 

 Bladen, 4 Wash., 706, has pointed out a road out of the confusion. 

 "The safest guide," says he, "to accuracy in making the distinction 

 is, to ascertain what is the result to be obtained by the discovery ; and 



