PRITCHARD S WEDGE PUOTOMETER. 



319 



TABLE IX. 



Wedge at 3.3 in. Slit = 2 mm. 



TABLE X. 



Wedge at 4.8 in. Slit = 2 mm. 



It is not to be understood from Table XI. and others, that no sensible heat of 

 the shorter wave-lengths is transmitted through the thicker parts of the wedge. 

 We do not here cite such observations where any have been made, because for 

 greater security no conclusions have been founded on the minute amounts there 

 noted, which are liable to relatively large errors of observation. 



