318 



PRITCHARD S WEDGE PHOTOMETER. 



In order to summarize the results of the prismatic measures in Tables III., 

 IV., and v., all the observations taken on the same successive points of the 

 wedge, though on different days, have been grouped together in Tables VII., 

 VIII., IX., X., and XI. The numbers in each horizontal line have been divided 

 in turn by the first number in the line, viz. that for " no tvedge." Thus in Table III., 



-^— =224, — '— = 273, the numbers which besin the horizontal line opposite "July 

 40.7 174 ° If J 



27" in Table VII. below. 



TABLE VII. 



Wedge at 0.3 in. Slit = 2 mm. 



TABLE VIIL 

 Wedge at 1.8 in. Slit = 2 mm. 



0".4 



o^5 



0".6 



0".7 



r.o 



July 27 



27 



August 9 



9 



9 



9 



August 10 



" 10 



" 10 



" 10 



Means 



37 

 36 

 37 

 20 

 35 

 27 

 28 

 36 

 18 

 17 



43 

 41 

 34 



40 



53 

 46 

 33 

 36 



37.2 

 42.6 

 37.5 

 33.0 



40.9 

 29.5 

 41.6 

 33.2 



118 

 128 

 105 

 120 

 104 

 110 

 107 

 105 

 103 

 100 



325 

 255 

 333 

 284 

 274 

 315 

 296 

 314 

 305 

 315 



29.1 ± 2.0 



40.8 ± 1.6 



36.9 ± 1.2 



110 ± 2.0 



302 ± 5.0 



