Chicago, Ill Paper - A Combined Vacuum-Pump and Table-Blowpipe

The apparatus described in this paper was designed by the writer, in the year 1869, for use in the laboratory of the " American Silver Steel Works," at Bridgeport, Conn., where only the vacuum-pump was erected ; but on two subsequent occasions I have had the combined vacuum-pump and table-blowpipe constructed as represented in the drawings, in which Fig. 1 is a general elevation of the apparatus, the air-chamber being sectioned vertically; Fig. 2, a plan of the air-chamber; Fig. 3, a vertical sectiotnal elevation of the vacuum-pump, the section being on line C L), of Fig. 4, which is a horizontal section on line A B, of Fig. 3. The vacuum-pump is constructed of copper, and consists of a vacuum-chamber, E, supported upon the upper expanded end of a vertical pipe, Q. The vacuum-chamber is provided with four nozzles, C, F, I, D (Fig. 4), two of which are shown in section at A, B (Fig. 3). Passing vertically through the centre of the vacuum-chamber E, is seen the water-supply pipe P, whose lower extremity incloses an internal pipe p, which is supported, and placed in communication with the vacuum-chamber E, by means of the two elliptical nozzles n, n. The upper part of the pipe p is closed by a conical cap, and its lower end is in the same plane with the extremity of the watersupply pipe P, within which it is placed. The relative sizes of the pipes P and p are such that an annular adjutage, one-sixteenth of an inch in thickness, is formed between their lower extremities, through which the water from the supplypipe P passes into the pipe &, drawing any air that may be in the