488 Dr. Herschei/s Experiments on the solar, and 



159th Experiment. 



Invisible rays. Pale -blue glass. 



5 53% 5li-"*i''i s r t tW 



It stops 583 invisible rays of heat. 



160th Experiment. 



Invisible rays, Dark-blue glasst 



5 5%% 52i-..i:f =,833 



It stops 167 invisible rays of heat. 



161st Experiment. 



Invisible rays. Indigo glass. 



o' 5H 5H 



5 54l 53-- 1 i'- J k = >5°° 



It stops 500 invisible rays of heat. 



i6id Experiment. 



Invisible rays. Pale-indigo glass. 



©' 5H 5H 



5 53i 52|-..-. 1: J = ,75o 



It stops 250 invisible rays of heat. 



163^ Experiment. 



Invisible rays. Purple glass. 



o' 51 £ 5of 



5 5H 5i|...if:i = } 7 2 7 



It stops 273 invisible rays of heat. 



