(dissenting).
As I understand it, my brothers and I do not differ as to the doctrines laid down in Westinghouse E. & M. Co. v. Wagner E. & M. Co., 225 U. S. 604, 32 S. Ct. 691, 56 L. Ed. 1222, 41 L. R. A. (N. S.) 653, and Dowagiac Mfg. Co. v. Minnesota Moline Plow Co., 235 U. S. 641, 35 S. Ct. 221, 59 L. Ed. 398, which still are our charter on this subject. We do not agree in their application; they think that this is a case where the patented improvement gave to the carbureter its whole value, and that seems to me not only unproven but disproven. In the ease of an improvement patent, the only situation in which the infringer has the burden of proof is where he has added an improvement of Ms own. In that ease he donates that improvement to the patentee, unless he can show howl much it contributed to the joint profit This is quite a different matter from the rule that where the invention is for an improvement, the patentee must in the first place apportion the contribution to the profit of the invention and of the prior art. The only ap*66parent, though not real, exceptions to this axe where tbie invention covers the whole article — not properly an instance of an improvement at all — or where, though an improvement, the patentee can show that the invention has given the article its whole value, which is really no more than an application of the general rule.
In the ease at bar there had been in the prior art carburetors with a single venturi and an “air-bleed”; there had also been carburetors with a double venturi; but there had never been a carburetor with a double venturi and an “air-bleed.” This combination was the invention, coupled with some incidental new designing, a factor to which we referred when we decided the first appeal, but which could hardly itself be invention. When the defendant was enjoined, it resumed the manufacture of the single venturi with an “air-bleed” and made some profit. That alone seems to me affirmatively to disprove the plaintiff’s claim; but quite aside from it, the carburetor was a very plain instance of an improvement, an addition to what went before, and the patentee has certainly not shown that the second venturi, or the “air-bleed” was the only source of the profit. It does not advance the argument to say that the sale would not have been made without the improvement. Probably it would not; in any case the issue of apportionment only arises upon that implication. But the same is true also as to the elements which were taken from the prior art; the sale depended upon them as well as oil the improvement, and the very issue is as to how far each factor quantitatively contributed to the profit. That may be, strictly speaking, an insoluble problem; but at least it does not help to a solution to observe that the improvement is one of the conditions necessary to the sale. Dowagiac Mfg. Co. v. Minnesota Moline Plow Co., supra, 235 U. S. 641, 35 S. Ct. 221, 59 L. Ed. 398, is quite in line with this result. Although it does not appear that the improvement was necessary to the sale, that was certainly possible, and the ease was disposed of on that assumption, for the patentee lost because he could not apportion the relative contribution of the old and the new. Nor does it seem to me vital that the second venturi or the “air-bleed” was not a detacha-. ble addition. I can see that if the improvement can be separated and the old and new are sold separably, there is a ready means of apportioning the joint profit when both are sold together; but I can see nothing more in separability than that. Certainly it is a wholly illegitimate inference to say, because the two' cannot exist apart, that the only value of the combination rests in the new parts. To confound the whole with any one of the constituents is equally gratuitous, whether each can exist alone or only in unison. Nothing in Dowagiac Mfg. Co. v. Minnesota Moline Plow Co., supra, 235 U. S. 641, 35 S. Ct. 221, 59 L. Ed. 398, lends any color to such an argument. So far as appears, the addition was so affixed to the old reaper that the machine would have been wrecked if it had been taken off.
Por these reasons the patentee in my opinion failed to make out a case for profits, and as it does not claim to have proved a reasonable royalty, the master was right.' However, if profits are to be allowed at all, I agree with the disposition made of the items in dispute.