20+ RECOLLECTIONS OF FORTY YEARS. 



anticipated France in the perfected use of the loco- 

 motive and the steamer, we are inclined to forget 

 that the real invention of machinery as applied to 

 navigation is due to two Frenchmen, Denis Papin 

 and Claude JoufFroy. 



Aristotle and Seneca seem to have been the first 

 to suspect the expansive force of steam, for they 

 attributed earthquakes to the transformation of water 

 into steam by the subterranean fires, a theory which 

 quite fits in with the present teachings of science. 

 Seneca, more explicit still than Aristotle, compares 

 the volcanoes to boiling water running out over the 

 sides of a vessel under the action of fire. Four hun- 

 dred years after Aristotle, Seneca, in chapter vi. of 

 his Natural Questions, wrote : 



u Certain philosophers, while attributing earth- 

 quakes to fire, also ascribe to the latter another 

 action. Fire, they say, when lighted in several places 

 at once, carries with it abundant vapours, which, 

 having at first no outlet, communicate to the air 

 with which they mingle a great expansive force. 

 If the air, thus charged, acts Avith great energy, 

 it breaks down all obstacles ; if it is more mode- 

 rate in its power, it merely causes the ground to 

 quake. 



"We see water boiling upon the hearth, and we 

 may be sure that if this limited phenomenon takes 

 place inside a vessel, it assumes tremendous propor- 

 tions when vast fires are acting upon vast masses of 



