278 HISTORY OP SCIENCE. 



body into its mass, while the word momentum designates the product 

 of the mass into the simple velocity. 



Many important propositions relating to Hydrostatics, Hydraulics, 

 and Pneumatics were investigated during the eighteenth century, and 

 the importance of such scientific investigations in practical engineering 

 and public works was everywhere acknowledged even in the earlier part 

 of the century. Any detailed mention of such investigations would 

 hardly prove of sufficient interest to the general reader, as their explana- 

 tion would necessarily assume the form of elementary treatises on these 

 branches of science. As allied to mechanical science in some respects, 

 we here may mention the beginning of some new lines of investiga- 

 tion. LA HIRE (1640 1718) first examined the muscular strength 

 and working power of men. Lambert, D. Bernouilli, Coulomb, and 

 others extended observations and experiments on this subject, and 

 Prony, Desaguliers, and others investigated the muscular power of 

 horses, The subject of friction in machines was studied successively 

 in France by AMONTONS (1663 1705), PARENT (1666 1716), Mus- 

 SCHENEROEK, CAMUS, COULOMB, and others contributed experimental 

 researches to this subject. 



