Morrison Waite

“ If, without the improvement, a machine adapted to the same uses can be made which will be valuable in the market, and salable, then, as was further said in that case, the inquiry is, 'What was the advantage in cost, in skill required, in convenience of operation or marketability,' gained by the use of the patented improvement? ”

“ If the old pump only cost as much as is claimed for the new, we cannot believe it would have commanded in the market any such price as the new sold for. We must conclude, therefore, that the cost of production has been much underestimated by the master. The testimony as reported is very unsatisfactory, and we are strongly inclined to think all has not been sent here which was presented. The attention of the parties was evidently directed much more to the rule of estimating the profits than to the detail of the expense of manufacture and sale. ”

“ If the appellant kept the control of its monopoly under the patent, it alone had the advantage of this market. Unless the appellees got the improved pumps, they could not become competitors in that field; and just to the extent they got into the field they drove the appellant out. Through their infringement they got the advantage of selling the pumps that had upon them the patented improvement. Without it no such sales would have been effected. The fruits of the advantage they gained by their infringement were, therefore, necessarily the profits they made on the entire sale. ”