468 Dr. Herschel's Experiments on the solar, and 



Sist Experiment. 



Candle. Violet glass. 



o' 59i 59i 



5 63% 6i|...3i-:i| = , 5 oo 



It stops 500 rays of flame-heat. 



8zd Experiment. 



Candle. Crown glass ; one side rubbed on 



emery ; the rough side exposed. 



o' 60 60 



5 6 3i 6o i-- -3i : i = >*59 



This glass, so prepared, stops 741 scattered rays of flame- 

 heat. 



83d Experiment. 



Candle. Coach glass ; one side rubbed on 



emery j the rough side exposed. 



o' 59i 59i 



5 hi 6o i ■ • • Si : H = >333 



It stops 667 scattered rays of flame-heat. 



84^ Experiment. 



Candle. Crown glass; both sides rubbed on emery. 



kq4- 



o' 59i 59 



4 



5 63 61 ...3£: if = ,385 



It stops 615 scattered rays of flame-heat. 



8$tb Experiment. 



Candle. Coach glass ; both sides rubbed on emery. 



°' 59i 591 



5 63 60% . . . si : 1 = ,320 



It stops 680 scattered rays of flame-heat. 



