6 EXPERIMENTS IN AERODYNAMICS. 



expressing any opinion other than may be implied in the very description of 

 these experiments themselves. 



It is just to say, finally, in regard to the extreme length of time (four years) 

 which these experiments may appear to have taken, that, beyond the fact of their 

 being in an entirely new field, nearly all imply a great amount of previous trial 

 and failure, which has not been obtruded on the reader, except to point out 

 sources of wasted effort which future investigators may thus be spared, and that 

 they have been made in the intervals of quite other occupations, connected with 

 administrative duties in another citv. 



