
90 U.S. 518 (____)
23 Wall. 518
THE TREMOLO PATENT.
TREMAINE
v.
HITCHCOCK & CO.
HITCHCOCK & CO.
v.
TREMAINE.
Supreme Court of United States.

*522 Mr. F.H. Betts, for the complainants below.
Mr. B.E. Valentine, contra.
*527 Mr. Justice STRONG delivered the opinion of the court.
We think that the order of the court directing that the record be amended by inserting in the bill an averment of the second reissue was properly made, under the circumstances of the case, though made after the final decree. For practically the rights of the complainants under the second reissue, and the defendants' infringement thereof were in issue under the answer and the replication. The amendment deprived the defendants of no rights which they had not enjoyed during all the progress of the trial. It may well be denominated only an amendment of form, because it introduced no other cause of action than that which had been tried. It is true that an amendment which changes the character of the bill ought not generally to be allowed after a case has been set for a hearing, and still less after it has been heard. The reason is that the answer may become inapplicable if such an amendment be permitted. But in this case the defendants were not prejudiced. They had every advantage they could have had, if the bill had originally averred the second reissue. The case is undoubtedly anomalous, but we think justice would not be subserved by denying to the Circuit Court the power to order such an amendment as was made, after the cause was tried precisely as it must have been tried if the bill had originally contained the averment inserted by the amendment.
We come then to the errors assigned by the complainants. *528 They relate to the estimate of profits reported by the master and confirmed by the court. The defendants were vendors of musical instruments, including organs and melodeons, which they purchased from the manufacturers. Some of these instruments contained the tremolo attachment, and others did not. For those containing such attachments they paid an additional price and they sold them also for an increased price. In the ascertainment of the profits made by them from the sales, they were allowed to prove the general expenses of their business incurred in effecting the sales of all musical instruments, and deduct a ratable proportion from the profits made by the sale of tremolo attachments. It is of this allowance the complainants now complain. It is said the patent infringed was not for the tremolo itself, but for the combination of the organ and tremolo, and it is argued that if the defendants obtained an extra price for the organ combined with the tremolo without incurring any additional expense, the whole of that extra price was obtained from the addition of the combination. And it is further insisted that the true rule in cases like the present is that if the infringing device is an integral part of the whole instrument, without which it is incapable of use, and for which a single charge is made, then in ascertaining profits on a part of the organization general expenses are to be apportioned according to the cost, or by some other equitable rule. But when the infringing device is an optional one, used or not at pleasure, and an extra price is charged and received for it when used, the true profit made is the extra sum received for the addition, deducting only such expenses as are incurred by reason of the addition. We think such a rule, even if it may sometimes be just, is inapplicable to the present case. We cannot see why the general expenses incurred by the defendants in carrying on their business, such expenses as store rent, clerk hire, fuel, gas, porterage, &c., do not concern one part of their business as much as another. It may be said that the selling a tremolo attachment did not add to their expenses, and therefore that no part of those expenses should be deducted from the price obtained for *529 such an attachment. This is, however, but a partial view. The store rent, the clerk hire, &c., may, it is true, have been the same, if that single attachment had never been bought or sold. So it is true that the general expenses of their business would have been the same, if instead of buying and selling one hundred organs, they had bought and sold only ninety-nine. But will it be contended that because buying and selling an additional organ involved no increase of the general expenses, the price obtained for that organ above the price paid was all profit? Can any part of the whole number sold be singled out as justly chargeable with all the expenses of the business? Assuredly no. The organ with a tremolo attachment is a single piece of mechanism, though composed of many parts. It was bought and sold as a whole by the defendants. It may be said the general expenses of the business would have been the same if any one of these parts had been absent from the instrument sold. If, therefore, in estimating profits, every part is not chargeable with a proportionate share of the expenses, no part can be. But such a result would be an injustice that no one would defend. We think it very plain, therefore, that there was no error in the rule adopted for the ascertainment of the profits made by the defendants out of their infringement of the complainants' patent.
We think also the master's report, confirmed by the court, was correct in its ascertainment of the general expenses. At least there is nothing before us to show that it did not conform to the second decretal order. The defendants submitted analyses of their books, from which it is to be presumed the master distinguished general from particular expenses.
It follows that neither the appeal of the defendants nor the cross appeal of the complainants can be sustained.
DECREE AFFIRMED; the costs of each appeal to be paid by the appellants.
