they have been done, and, ‘in the light of the accomplished result,’ it is often a matter of wonder how they so long ‘eluded the search of the discoverer and set at definance the speculations of inventive genius.’ Knowledge after the event is always easy, and problems once solved present no difficulties, indeed, may be represented as never having had any, and expert witnesses may be brought forward to show that the new thing which seemed to have eluded the search of the world was always ready at hand and easy to be seen by a merely skillful attention. But the law has other tests of the invention tha subtle conjectures of what might have been seen and yet was not. It regards a change as evidence of novelty, the acceptance and utility of change as a further evidence, even as demonstration. And it recognizes degrees of change, dividing inventions into primary and secondary, and as they are, one or the other, gives a proportionate dominion to its patent grant. In other words, the invention may be broadly new, subjecting all that comes after it to tribute; it may be the successor, in a sense, of all that went before, a step only in the march of improvement, and limited, therefore, to its precise form and elements, as the patent in suit is conceded to be. In its narrow and humble form it may not excite our wonder as may the broader or pretentious form, but it has as firm a right to protection. Nor does it detract from its merit that it is the result of experiment and not the instant and perfect product of inventive power. A patentee may be baldly empirical, seeing nothing beyond his experiments and the result; yet if he has added a new and valuable article to the world's utilities, he is entitled to the rank and protection of an inventor. 36
Subsequently, we see the D.C. Circuit embrace the importance of hindsight reconstruction, and continue to equate obviousness with ‘invention’ in In re Pupin.37
We cannot hold that, after Steinmetz's disclosure, appellant's apparatus became obvious to any one skilled in the art. To say that would simply mean that, faced by a crying need for a device which would remove the objectionable hum from sound– reproducing systems, inventors of electrical appliances and those skilled in the art were blind to the aggressively apparent for more than six years after the announcement of the Steinmetz formula. Problems which vex the brain for many a weary hour and many a weary year become obvious to all the world, once they are solved; but their obviousness after the fact does not necessarily prove their obviousness before the fact. 38
220 U.S. at 434-435. (citations omitted)
55 App.D.C. 14, (D.C.Cir.1924).
55 App.D.C. at 16.