PRITCHARD S WEDGE PHOTOMETER. 



315 



Bolometer, No. 16 (1 mm. aperture), accurately adjusted for the varying focus of each point 

 the spectrum. 



Setting on Slit (before mounting prism) 



in 







0' 0". 



.. 



D 2 (after 



« 



4( 



) 



315° 48' 15". 



Current of Battery, 0.040 Ampere. 

 Header at Circle and Wedge, J. P. 



u 



Galvanometer, F. W. V. 



Watcher for Clouds, C. 



Object 



measurement of transmission of Pritchard wedge for different parts of the spectrum. 



Time, 11 a.m. to 2.15 p.m. 



TABLE IV. 



1 x 



No 

 Wedge. 



Wedge 

 at 0.3 in. 



Wedge 

 at 1.8 in. 



Wedge 

 at 3.3 in. 



Wedge 

 at 4.8 in. 



Wedge 

 at 6.3 in. 



* <K4 

 1 < (Dev. 46° 40') 



52.0 

 56.1 



12.7 

 13.3 



1.9 

 1.1 









1 Mean of Series 1 



54.1 



13.0 



1.5 









> 0*.5 



J * Dev. (44° 58') 



267.0 

 244.0 



68.4 

 65.9 



9.0 



9.7 



1.4 

 1.1 



• • 



• • • 



i • • 

 * * * . 



1 Mean of Series 2 



256.0 



67.2 



9.4 



1.3 



• • • 



Ill 



► 0^.6 



< (Dev. 44° 7') 



566.0 



588.0 



157.0 



158.0 



21.2 

 19.4 



3.2 



2.4 



0.4 

 0.2 



0.3 



• • • 1 



• 



| Mean of Series 3 | 



577.0 



158.0 



20.3 



2.8 



• • • 1 



> OmJ 



< (Dev. 43° 37') 



799.0 

 733.0 



311.0 

 319.0 



83.5 

 88.0 



21.5 

 21.8 



5.1 



1 5.1 



1.0 

 1.4 



Mean of Series 4 



766.0 



315.0 



85.8 



21.7 



5.1 



1.2 



1 * 1*.0 



933.0 



578.0 

 581.0 



311.0 



288.0 



152.0 

 158.0 



155.0 



83.0 

 80.5 



37.9 1 



| < (Dev. 42° 54') 



1014.0 



34.9 



Mean of Series 5 



974.0 



580.0 



300.0 



81.8 



36.4 



► 0M 



< (Dev. 46° 40') 



42.9 

 42.6 



42.8 



8.6 

 9.8 



1.5 

 1.1 









| Mean of Series 6 | 



9.2 



1.3 





| .1 



" [ Clouds prevented the completion of these series. 



> <K7 



< (Dev. 43° 37') 



756.0 

 721.0 



299.0 

 286.0 



78.5 

 79.0 



19.8 

 21.7 



5.1 

 5.9 



1.1 

 1.1 



Mean of Series 7 



740.0 



293.0 



78.8 



20.8 



5.5 



1.1 



> U.O 



< (Dev. 42° 54') 



948.0 

 896.0 



468.0 

 572.0 



520.0 



260.0 



282.0 



143.0 

 150.0 



78.8 

 85.5 



31.9 

 37.2 



Mean of Series 8 



923.0 



271.0 



147.0 



82.2 



34.6 



