Application of the Blow-pipe, 54^ 



than the flieet EE, any fuperabundant quantity of air which 

 mav be thrown into either compartment will pafs up the pipe 

 and efcape. 



In fig. 4, the bellows are reprefented as nearly deprefled, 

 and the air itluing from the open fide of the hood into the 

 compartment immediately over it, which is about half filled 

 with air. The other compartment is reprefented as being 

 completely full of that fluid. The water is reprefented in 

 commotion, that the aAion of the machine mav be rtrongly 

 marked J hut the motion of this fluid is in reality fo gentle, 

 that the regularity of a blaft is not thereby perceptibly af- 

 fected. 



If it be defired to fill both compartments with one kind of 

 air, without the trouble of turning, the hood, by opening the 

 cock of communication in the pipe V, any air which may be 

 thrown into either compartment will divide itfelf equally be- 

 tween both of them. 



It mull be obvious that the air in the compartments on 

 each fide of the flieet and pipe of copper E E, D, fig. 4, is 

 fubjedt to hvdroftaiic prcfl'ure, and that of courfe it will pafs 

 out at the pipes of delivery, unlefs ftopt by the cocks. Thefe 

 pipes are omitted in fiir. 4, but have been already defcribed, 

 together with their cocks, at MNO, mno, fig. i. 



The leather and joints of the bellows are evidently fub- 

 jefted to the weight of a confideralile colunm of water; but 

 this preflTure, being external, tends to tighten them, and ren- 

 ders this part of the machine fo perfect, that if the orifice of 

 the fuction-pipe be clofed, it will be found impolhble to raife 

 the top of the bellows, without the imnienfe force which 

 would be neceflary to produce a vacuum within them. This 

 would not be the cafe if the fmalleft leakatre took place. 



It is now time 10 give an account of the purpoles to which 

 the hydroftatic blow-pipe may be applied, and the manner 

 of applying it to them. 



This inltrunient may he employed to fupply with atmo- 

 fpheric air a fmall flame for the various purpofes of -the 

 nioutli blow-pipe. To efleci this, it is oidv neeefl'ary to 

 place a lamp or candle on the hand 'I'V, which is upheld by 

 the fcrew S, fig. i. Bv raifing or lowering this (crew, or by 

 Aiding backward or forward the block through which it 

 pali'es, the ftand mav be fo adjullcd, as that the Ihaight 

 mouth-piece X will jiiit enter the flame, Ihe handle uuilt 

 thru be worked until the blad obtains the proper llrenglh. 

 This generallv hajipens when the water has rifen above tlie 

 partition li three or four inches. If it ihould be raifed higher, 

 Q 3, the 



