AMEBICAN BALLAST LOa CO. OF NEW TORK ». BAENEB. 467 �in the ■water when the ship careens towards it, but is carried down and submerged until its buoyant power checks the ship and returns her to an upright position. This, it seems to us, is a different inven- tion from that described and claimed in complainant's patent. It may have been the resuit of a study of the complainants' device, stim- ulated by its success, but the defendants have rejected one of the essential elements of complainant's combination, and substituted in its place a new mode of accompli shing the same object, which, in our judgment, is not a mechanical equivalent, and is not similar in prin- ciple or operation. The buoyancy of the air chamber on one side of the ship does not perform the same function as was performed by the weight which is dispensed with on the other side. The function of the weight was to drag down the side of the ship b^ which it' was being lifted from the water. The function of the aii: chamber is to reSist the tendency of the ship in careening to bury it under the wa- ter. The quality of buoyancy is not called into action at all in com- plainant's device. It is useful to that device only so far as it renders the logs easy of transportation to the ship, and so far as it renders the logs inactive when the vessel is in an upright position. Its use in any other way, or for any other purpose, is not suggested in com- plainant's specifications or claim. �Complainant's patent cannot be construed to eover all methods by which vessels may bekept upright in port by mjeans of contrivances fastened on the outside and floating in the water, but only such as are substantially identical with the device described ih the patent, in construction, form, and principle of operation. Case v. Brown, 2 Wall. 320. �Being clearly of opinion that the charge of inf ringement is not sus- tained, and that there can be no decree in favor of the complainant, it is not necessary for us to consider the defence of want of novelty Bdt up by the answer. �Bill dismissed. ��� �
