184 



ATTRACTION. 



1* 



A, and there is a smaller cylinder, a,* rising in the centre to receive 

 an interior gas pipe ; the rings are to receive the cords that are to 

 suspend the cylinder by passing over pully wheels at c c, fig. 2. 



2. D is a slightly conical cask, to be filled with water in which A 

 is suspended by the cords already mentioned, and which are weight- 

 ed at d d, so as to keep the air vessel in equilibrio. 



3. Fig. 3 represents a tube of copper or lead, which is fastened 

 within the cask D, so that the limb / rises in the center and passes up 

 into a, fig. 1, when the air vessel is down, and the stop cock m is 

 open, for the escape of the common air. The other limb e is fas- 

 tened firmly to the cask at the side. 



4. Fig. 4 represents the mouths of two of the interior tubes with 

 additional tubes fitted air tight, with corks through the trumpet shap- 

 ed orifices, i i, and terminating, after curvature, in a frustrum of pla- 

 tinum at/. This apparatus of tubes is used for the compound or 

 oxy-hydrogen blowpipe of Dr. Hare, and can be taken off by double 

 jointed screws at o o, and also at i i, and any other apparatus can be 

 attached. At b 6, is a thin slip of wood, acting both as a guide and 

 a scale to the air vessel. 



It is obvious that if there are two casks and two air vessels, they 

 will form convenient reservoirs for oxygen and hydrogen. Mine 

 contain together fifty gallons, and by means of weights laid on the air 

 vessels, the gases are made to issue at j 9 with all necessary force. 

 Nothing can be more convenient for the compound blowpipe ; for the 

 oxygen or the hydrogen blowpipe alone ; for the common air blowpipe ; 

 for gas lights ; for musical tones with hydrogen ; for communicating 

 oxygen and hydrogen through a tube to the pneumatic cistern, and 

 for many other purposes, sufficiently obvious to a practical chemist. 

 Smaller instruments upon this principle, are convenient for the respi- 

 ration of gases, a proper mouth piece being fitted to e g, fig. 3. 



Which may be furnished with a small stop cock, to let off common air. 



