INTHoDltTlON ( 



te.\tur»», tlio tilling of laml, niitl the aecelerutiou 

 of (•lu'inii-al activities in tlic soil, are esstMitially 

 tiuestions of jihysics; and tln'so are the kinds 

 of sc'iontifu* i)roljK'nis which the farmer needs 

 lir.st tt^ ai)i)rehen<l. 



1."). Mechanics. In practice, mechanics is an 

 jipplication of the laws of physics. The ele- 

 mentary jM-iiieiples of mechanics me ajijirehended 

 hy the farmer unc<^ns«'ionsly, as a result of 

 exi)erience ; hut since niodi-rn agriculture is 

 impossible without numerous and often elaborate 

 mechanic'd devices, it follows that it is not 

 • •nough that the farmer be self-taught. At every 

 tiu-n the farmer uses or applies physical forces, 

 in too|>, vrliicles, and machines. His work 

 often takt'S him into the held of civil en- 

 gineering. To show how much th<^ farnu>r 

 is dependent on j>ractical mechanics, Wf need 

 mention only imjdements of tillage, problems 

 associated with the diaughts of liorse tools, 

 the elaboratr' harvesting machinery, threshers 

 and feed-mills and milk-working machinery and 

 the power to run tiiem, fruit evaporating ma- 

 chinery, pumps, windmills, hydrauli** rams, con- 

 strui'tion of water supplies, problems of animal 

 locomotion, 



1(». Plant-knowl»'«lge, or botany. Sint-t- the 

 I 'hint is the rTisnary product of the farm, a 

 knowledge ot it3 characteristics and kinds is of 



