302 



EFFLUX OF GASES 



ture of a vessel, reaction of efflux takes place as ii 

 liquid bodies. The ascent of a rocket is due to th< 

 reaction of the gases generated by the lighted powder 



FIG. 200 (A, real sine \ B, \ real size}. 



the motion of the rocket taking place in a directk 

 opposite to that in which the gases are issuing; to t 

 same cause are due the rotatory motion of a catherin 

 wheel and the erratic movements of a squib. 



