Aaron Arnold, of the city of Troy, N. Y. has invented a new and ingenious steam boiler feeder, for which he has taken measures to secure a patent. The nature of the invention consists in having a small hollow closed metallic vessel, which is hung on a balance outside of the boiler, and has communication at the top with the steam, and at the bottom with the water of the boiler, and is connected with the throttle valve or cock in the feed pipe. The object of this apparatus is to regulate the quantity of water to be supplied to the boiler by a pump, so as to maintain the water in the boiler at a proper level. As the small vessel spoke,i m'communicates with the stearci chaKsbes* asKl the water in the boiler, it receives both steam and water, the latter being always at the .sa?.tte level as that v,( the boiler, ft is balanced on a centre in (such a manner that when the ss:.i id fiw (-oiler is at the proper line, it remain;:, poised on irs centre, and keeps the tbroHie valve in the feed pipe open to the exact width that will supply the boiler with water commensurate to the steam used. When the water in the boiler falls below the proper line, the water in the small outside vibratifig vessel diminishes, which causes it to rise and open the throttle valve somewhat wider, and letting more water to the boiler. The reverse action takes place when the water in the boiler rises above the proper line. The vibrating outside vessel is guided by the amount of water in the boiler to regulate the throttle valve.