45^ Dr. Herschei/s Experiments on the solar, and 



^ist Experiment. 



Sun. Pale-indigo glass, 



o' 62 62 



5 6 7 % 6 4 | . . . 5 J : a 3 = , 4 <J8 



It stops 532 rays of heat, and 978 of light. 



42<i Experiment. 



Sun. Purple glass. 



o' 61J 61J 



5 6?i 6^... 6 '.2^ = 417 



It stops 583 rays of heat, and 993 of light. 



43d Experiment. 



Sun. Violet glass. 



6 2 i 62£ 



68£ 65*. . . 5 i : 3 = ,511 



It stops 489 rays of heat, and ggs of light. 



Transmission of Solar Heat through Liquids. 



I took a small tube, i|- inch in diameter,* and fixed a stop 

 with a hole -| inch wide at each end, on which a glass might 

 be fastened, so as to confine liquids. The inner distance, or 

 depth of the liquid, when confined, is three inches. Placing now 

 the empty tube, with its two end glasses fixed, upon the trans- 

 mitting apparatus, I had as follows : 



44^ Experiment. 



Sun. Empty tube, and two glasses. 



o' 53 53 



5 59 55i • • • 6 = ^1 = >45 8 



• Sec Plate XXII. Fig. 2. 



