THE APPLICATIONS OF PHYSICAL FORCES. [BOOK iv. 



The trunk engines and oscillating engines, which have been 

 described in the paragraphs relating to transmitting machinery, 

 are often employed in steam navigation, whether on rivers or at 

 sea. I think I have already said that the first are chiefly used 

 in the English marine. In general the differences to be met with 

 between 'the fixed land engines arid the marine are almost all due to 

 modifications rendered necessary by the question of space and 

 position. 



