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



g6tb Experiment. . 



Red rays. Crown glass. 



°' 75$ 75i 



5 78 77|...2|:ii = ,7o6 



This glass stops 294 rays of the same sort of heat. 



gjth Experiment. 



Red rays. Coach glass. 



°' 541 53i 



5 55i 54i • • • H : 1 = > 8o ° 



It stops 200 rays of the same sort of heat. 



gStb Experiment. 



Red rays. Iceland crystal. 



o' 7$i M 



5 78 77i • • • if = H = ,8oo 



This substance stops 200 rays of the same sort of heat. 



ggtb Experiment. 



Red rays. Calcinable talc. 



5 5$i 52f • • • if : if = >S6T 



It stops 133 rays of the same sort of heat. 



100$ Experiment. 



Red rays. Dark-red glass. 



o' 7% 76J- 



5 7H 77i--- 1 i : i= > 3°8 



This glass stops 692 rays of the same sort of heat. 



