the terrestrial Rays that occasion Heat. 469 



S6th Experiment. 



~, j. f Crown glass. \ One side of each rubbed 



\ Coach glass. J on emery. 



o' 55t 55w 



5 59 5 6 f • • • Si ■ I = .280 



These glasses stop 720 scattered rays of flame-heat. 



Syth Experiment. 



c ,, f Crown glass. \ Both sides of each rubbed 



an e ' \ Coach glass. J on emery, 



55t 55~q 



59i 57 • • • Si : *t = >333 



These glasses stop 667 rays of flame-heat. 



SSth Experiment. 



C Crown glass ; the rough side to the candle. 

 Candle J Coach glass; ditto. 



j Crown glass ; rough on both sides ; 

 (_ Coach glass; ditto. 



o' 5^ m 



5 59i 57i • • • af : t = >%&> 



These four glasses stop 870 scattered rays of flame-heat. 



89^ Experiment. 





Candle. 



Olive-colour, burnt in glass. 



0' 



60 



60 



5 



63 



6of . . . 3 : f = 



This glass stops 792 scattered rays of flame-heat- 



goth Experiment. 



Candle. White paper. 



°' 57i 57i 



5 6of 57i • • • 3 • I = »2o8 



This substance stops 792 scattered rays of flame-heat 

 mdccc. 3 P 



