AND THE MODE OF TEACHING THEM. 439 



remarkable that speculative knowledge itself is amply repaid for 

 the time thus lent to practical science ; and that man advances in 

 the scale of intellectual being, not only by the acquisition of new 

 materials for the exercise and development of his intellectual 

 powers, but still more by his release from the thraldom of those 

 corporeal occupations to which his bodily wants coerced him. 



It is, in fact, one of the precious advantages of applied science, 

 that its results have delivered man from a great part of that toil 

 to which he was condemned in the infancy of society for the 

 supply of his animal wants ; from that abject condition, in 

 which the body is at once his taskmaster and his slave. This re- 

 volution has been accomplished by the knowledge which he has 

 acquired of the forces of nature, and the means which he has con- 

 trived to compel them to act on his behalf. The Romans, with 

 whom mechanical science was in its infancy, had recourse to human 

 labour in grinding their corn ; in crushing the seeds of plants, and 

 expressing their juices; in removing the earth and the water which 

 covered the treasures of the mine. Slaves, in immense numbers, 

 were condemned to these toils, toils so severe, as to constitute the 

 heaviest punishment, next to death itself. But man has since 

 learned the art of employing the forces of nature, the action of 

 the wind, and of the running stream, to accomplish his will. 

 He has even learned how to develope such forces when otherwise 

 latent ; to call into action the elastic forces of steam, and of the 

 gases ; and constrain them to execute his commands. 



We shall better learn to estimate the benefits which applied 

 science has conferred upon man, if we reflect for a moment upon 

 the advances in social progress which the application of any of 

 these agents has effected, and the character of superiority that 

 has attached to the nation which has been the first to discover and 

 employ them. 



Let us take, for example, the combination of the moving force 

 of air, and the resisting force of water, in propelling and guiding 

 the vessel on the waves. What advantages has not this appli- 

 cation of natural forces conferred upon the people of antiquity 

 which was the first to make it ? What advantages does it not 

 still bestow upon the nation, whose pre-eminence in nautical skill 

 has earned for her the proud title of " Mistress of.the Seas " ? Sho 

 carries the products of her industry across the ocean, to exchange 

 them for the riches of distant nations. She spreads the terror of 



