440 F. H. Bigelow — Inversion of TemyerattLves^ etc. 



without regard to the phase times, controlling the amplitude 

 of the crests. It must be remarked that nothing less than a 

 very accurate determination of the period of rotation of the 

 sun, would permit the survival of any residuals in such an 

 irregular curve. Hence by as much as there remain residuals, 

 which being derived from very different sources yet produce 

 the same curve, the argument in favor of the existence of the 

 system of forces in nature corresponding to them is greatly 

 strengthened. 



Temperature /erTations in the 2668 Jay Perfoo (s/ioM/rJ V >recf '#• wfrr&c change* 

 The. Y&ars J 892. J 893. 130 US 5 tc) hurts. 



■Ini/erse 



Since the labor of constructing such elaborate tabulations is 

 very great, especially in extending the same over a series of 

 years, resort was had to a shorter process for the years 1878- 

 1891. It had been observed that the temperature variations of 

 the Dakota Stations were the least distorted from the funda- 

 mental curve, doubtless due to the continental location, the 

 amplitudes being large and the phases steady, and hence five 

 stations, Fort Buford, Bismarck, St. Vincent, Moorhead and 

 Huron, were employed for this purpose. By a similar method, 

 allowing one day for the reduction to the origin, the following 

 table and curves were constructed. In the case of each system 

 of curves the plotting is moved 8 hours to the left to allow for 

 the longitude on the Ephemeris not yet taken into the count, 

 the rule covering all cases being, " For any station correct the 

 epoch and succeeding dates of the Ephemeris by adding the 

 longitude from Greenwich and the time of eastward move- 

 ment from the American origin." 



