46 DISCOURSE ON THE STUDY 



bellows, it was, on one occasion, attempted to em- 

 ploy the steam itself in, apparently, a much less 

 circuitous manner ; viz. by directing the current of 

 steam in a violent blast, from the boiler at once into 

 the fire. From one of the known ingredients of steam 

 being a highly inflammable body, and the other that 

 essential part of the air which supports combustion, 

 it was imagined that this would have the effect of 

 increasing the fire to tenfold fury, whereas it sim- 

 ply blew it out; a result which a slight consider- 

 ation of the laws of chemical combination, and the 

 state in which the ingredient elements exist in 

 steam, would have enabled any one to predict 

 without a trial. 



(38.) Ex. 3. (35.) II. After the invention of 

 the diving-bell, and its success in subaqueous pro- 

 cesses, it was considered highly desirable to devise 

 some means of remaining for any length of time 

 under water, and rising at pleasure without assist- 

 ance, so as either to examine, at leisure, the bottom, 

 or perform, at ease, any work that might be required. 

 Some years ago, an ingenious individual proposed a 

 project by which this end was to be accomplished. 

 It consisted in sinking the hull of a ship made quite 

 water-tight, with the decks and sides strongly sup- 

 ported by shores, and the only entry secured by a 

 stout trap-door, in such a manner, that by disengag- 

 ing, from within, the weights employed to sink it, 

 it might rise of itself to the surface. To render the 

 trial more satisfactory, and the result more striking, 

 the projector himself made the first essay. It was 

 agreed that he should sink in twenty fathoms water, 

 and rise again without assistance at the expiration of 



