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PROCEEDINGS OF THE 



Nov., 1858. 



by a central partition of the same material, parallel to the two 

 bases of the cylinder, into two air tight compartments, an upper 

 and a lower. Two hollow cylindrical projections, of tin, 2 inches 

 long, and 3 inches in diameter, are soldered on opposite sides of the 

 Aspirator, with their axes in the same line, and in a plane equidis- 

 tant from the bases of the Aspirator. These projections serve as 

 trunnions or pivots, by which the Aspirator can be rotated on 

 proper supports, so as to bring either compartment uppermost. 

 Within the area inclosed by each of these projections or pivots, 

 are two apertures, one communicating with the upper, and the 

 other with the lower compartment, and in each of these aper- 

 tures there is soldered a leaden tube. On One side (left side 

 of figure) these tubes are short, projecting within only an inch, 

 and without, only an inch or two beyond the extremity of the 

 pivot. These tubes are made to communicate with a common 

 outlet, by means of a two-branched tin tube, in the form of the 

 letter Y, each branch" being connected with one of these tubes by 

 an India-rubber flexible tube, 6 inches in length, and the stem of 

 the Y forming the common outlet, from which the air issues when 

 the Aspirator is in action. On the other side, the leaden tubes also 

 project outwardly an inch or two beyond the end of the pivot, but 

 within they are long and curved, in the form of the letter U, with 

 two long branches, the bend of the U being, for each tube, near 

 the base of the Aspirator, and the aperture of the inner branch 

 not far from the partition separating the two compartments ; these 

 tubes are also so bent towards one side of the Aspirator, that this 

 aperture of the inner branch shall be as far as possible from the 

 two pivots, and on the other side of the Aspirator, there is, in the 

 partition, an aperture one-fifth of an inch in diameter, forming a 

 communication between the two compartments of the Aspirator. 

 The two ends of these tubes projecting externally, are furnished, 

 by means of another two-branched Y tube and India-rubber 

 connectors, with a common inlet, through which air enters when 

 the Aspirator is at work. If the India-rubber tubes be firmly 

 compressed, the ingress or egress of air, or other fluids, may be 

 entirely prevented at any, or all of these four points of communi- 

 cation, with the interior of the Aspirator. For compressing the 

 India-rubber tubes, I employ the wooden pincers closed with 

 brass springs, which are used in this country by laundresses for 

 fastening clothes to the lines, while hanging out to dry, and which 

 can be had for a few cents in the shops. 



