466 FEDERAL REPORTER. �The claim is "the method of ballasting vessels by means of float- ing logs, of suitable size, weight, and construction, attaehed to said vessels by ropes and chains, and arranged along-side thereof, sub- stantially as specified." The device described in this patent bas been introduced by the oomplainant into very general use in the ports of Boston, New York, Philadelphia, and Baltimore, among ves- sels requiring ballast to keep them upright in port when empty, and particularly among grain vessels, which are required to be completely emptied and ceiled before receiving cargo. The defendants, in their answer, deny that the device used by them is an infringement, and also charge that the complainant's patent is invalid by reason of long prior knowledge and public use. The device used by the defendants is one for which a patent bas been granted to them, No. 232,435, dated September 21, 1880, for harbor ballast for ships. It is also to be attaehed to the outside of the ship, but on one side only. It consists of a floating water-tight box or pontoon, divided into a lower and an upper compartment. The lower compartment is filled with water, and the upper one is air-tight and empty. It is attaehed to one side of the ship by means of chains or ropes, — one fastened to the ship's deck, and the other carried under her keel and up the other aide. If the ship careens away from the side on which it is attaehed, the weight of the box and of the water contained in the lower compartment pulls the ship back to an upright position. If the ship careens towards the side on which it is attaehed, the buoy- ant power of the empty air-tight compartment is sufficient to check the tendency of the ship to overturn towards that side. �The conclusion to whicb we'have arrived is that there is no in- fringement. The device of the complainant is a combination of two counter-balance weights. That the weights float in the water is only an incident of their usefulness, aud bas nothing to do with the essen- tial principle of their action. As stated in the specifications of the patent, it is only the resistance of the weight of the log when the yessel, in keeling over, attempts to lift it from the water which pro- duces the result intended. It is the two counter^balaneing. weights which the inventer relied npon, and one without the other would be useless. �The defendants' device makes nee of but one weight, and the coun- ter-balance is produeed by the buoyant power of the air-tight cha,m- ber of the pontoon. This is; made efficient by haying the pontoon, not loosely floating by the sido of the ship.^as is the case with the ballast logs, but so secured to the ship that it cannot remain floating ��� �
