10 MECHANICS. 



a person well versed in the science of mechanics, would 

 appear nearly as absurd. 



It is well worth while to look at the achievements made 

 through a knowledge of mechanical principles. Compare 

 the condition of barbarous and savage tribes with that of 

 modem civilized nations. The former, scattered in com- 

 fortless hovels, subsist by precarious hunting, or on scanty 

 crops raised on patches of ground by means of the rudest 

 tools. The latter are blessed with smooth, cultivated fields, 

 green meadows, and golden harvests. Commerce with 

 its hum of business, extending through populous cities, 

 and along a hundred far-stretching lines of rail-ways, scat- 

 ters comforts and luxuries to millions of homes ; while 

 ships for foreign commerce thread every channel and 

 whiten every sea. The contrast exhibits the difference 

 between ignorance on the one hand, and the successful 

 application of scientific principles on the other. It is our 

 present object to point out to the farmer the advantages 

 which would result from a wide extension, through all 

 classes, of this knowledge, that the opportunities may be 

 continually increased for general improvement. 



CHAPTER n. 



GENERAL PRINCIPLES OF MECHANICS. 



Having briefly pointed out some of the advantages to 

 tlie farmer of understanding the principles of the ma- 

 chines he constantly uses, we now proceed to an examina- 

 tion of these principles. It will be most convenient to 

 begin with the simpler truths of the science, proceeding, 

 as we advance, to their apj^lication in the construction of 

 machines. 



