EXPERIMENT STATION RECORD. 



Vol. XXXIV. February, 1916. No. 2. 



Extension teaching and demonstration will deal with both the 

 product of experience and scientific theory — with the results of good 

 practice as worked out by leading farmers, and the results of the 

 investigations and experiments made by the stations. The extension 

 worker, therefore, will have these two general sources of informa- 

 tion at command, which will often need to be fitted together or 

 reconciled. 



Both classes of information require care in interpretation as 

 applied to particular sets of conditions or questions. Especially 

 is it important that local experience should not be too implicitly 

 relied upon or accepted as final. It is useful to the extent that it is 

 rightly interpreted, but it is very subject to misinterpretation, and 

 it is often taken to furnish the whole answer. It is "many times 

 unsuspecting, blind, and prejudiced," and at best it is an insufficient 

 and often unreliable means of advancing learning or understanding. 



We may think of science as the relation of cause and effect. It 

 is the cause-and-effect relationship which gives us something de- 

 pendable upon which to build. Whenever we observe an effect there 

 has been a cause; and we now know that in agriculture, as much 

 as in astronomy, the same cause acting under precisely the same 

 conditions will produce precisely the same effect. When we do not 

 understand why certain events occur, the reason is that we do not 

 understand the forces which operated to produce the events. This 

 is where practical experience breaks down. It can not explain rela- 

 tions between what it sees and the probable cause, because it can 

 not measure conditions it does not understand or the effect or forces 

 it knows not of. For this reason it has never discovered a law or 

 explained a phenomenon. Its doctrines are purely empirical and its 

 methods rule of thumb instead of resting on reason and understand- 

 ing. It may serve to bring the level of agricultural practice nearer 

 that of the leading farmers of each community, but it does not go 

 outside of or beyond itself. Its eye is upon the past rather than 

 upon the future, and its criteria of excellence are found in the rec- 

 ords of tradition, often shown to be in error when a finer test is 



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