TRESPASS AND INSURANCE 1161 



its own physical characteristics or its arrangement in the new combination apparatus. 

 Adopting this view, the Supreme Court held the claims in suit to be invalid. 



Walker thus eventually lost the fruits of his inventive efforts insofar as a broad 

 range of equivalents is concerned. He had left relatively narrow claims describing 

 more or less specifically the features of his apparatus and presumably remained pro- 

 tected against a Chinese copy of his device. Quite obviously, however, it is possible for 

 anyone to add a substitute for Walker's addition to the old Lehr and Wyatt apparatus. 



This case will undoubtedly remain a center of controversy until further clarified, 

 overruled or re-afifirmed. It leaves the question open as to whether and under what 

 facts a combination invention is broadly new or narrowly new. Admittedly, all of the 

 elements in the Walker complete apparatus were separately old, and, under standards 

 of combination invention generally recognized previous to the Halliburton decision, 

 there had been no distinction made between combinations in general and combinations 

 where one element was said to represent the exact point of novelty. 



A general rule, at least, may be drawn from this case, namely, that if the invention 

 is but a short step forward, the claims to be valid must particularize that step, leaving 

 the field open to others to provide other means to achieve the same result. It does not 

 abolish all reward to the inventor, but restricts the extent of his patent monopoly. 



