OF ARTS AND SCIENCES. 



249 



TABLE III. — Continued. 



In Table IV. these measures are compared. The first column 

 gives the same number for reference as in Table III. Tlie second 

 column gives the wave-lengths of the lines in the solar spectrum, with 

 which the lines here measured are assumed to be identical. Each 

 measurement is reduced to wave-lengths by the formula given above. 

 The residuals found by subtracting the assumed wave-lengths from 

 these are given in the subsequent columns. Each plate is designated 

 by its appropriate number. 



