f 57 1 



This cylinder fhould be riveted or fcrewed by means 

 of an iron collar or llraps to the deck it paffes thro', 

 both above and below as at ^ «; and be farther fe- 

 cured by fome hold-fafl near b, to keep it fleady in 

 working. 



Fig. 2. Is a bottom of wood 47 inches thick, 

 with a projecting rim at its bafe for the metal cy- 

 linder to red: on, when cemented and fcrewed to the 

 wood. 



The centre of this bottom is excavated for the re- 

 ception of tUe crown of the nofle. 



In the fame figure, the nofle is reprefented with 

 its crown like a bowl-difli, to condenfe the air gra- 

 dually, without refinance, in its advance to the more 

 contrafted bafe of the inv<rrted cone, /. e. the top or 

 entrance of the nofle. About two-thirds down this 

 nofle may be fixed a male fcrew, as c. c. for the 

 purpofe hereafter mentioned. 



N. B. The forcing pump fliould be cafed in wood, 

 to protect it from outward bruifes, which would pre- 

 vent the working of the pifl:on, and ruin its cfFefts. 



The leather round the embolus fliould be greafed 

 when ufed. 



Fig. 3. Is a crutch-handle faflened to the embolus 

 A. by its iron legs B. B. 



A. is a cylinder of wood, cafcd with leather fo as 

 to fit well, but glide fmoothly in the metal cylinder; 

 having an opening as large as its flrength will permit, 

 for the free accefs of atmofpherick air. 



C. is 



