VOL. XC.] 



PHILOSOPHICAL TRANSACTIONS. 



769 



Min. Stove. Dark red glass. . 



Evper. 176. 58 58 



3 64£ 6o£ . . . 6£ : <Z\ — .570. 



Min. Stove. Orange glass. 



Exper. 177. 55% 55\ 



3 60£ 57| . . . 54 : 2\ = A76. 



Min. Stove. Yellow glass. 



Exper. 178. 57$ 57l 



3 6l£ 59|...4.:2i=.531. 



Min. Stove. Pale green glass. 



Exper. 179- 5l£ 51 J 



3 56f 53| ..4£:l£ = .368. 



Min. Stove. Dark green glass. 



Exper. 180. 50 49 J 



3 53| 50£...3£:1-L = .300. 



Min. Stove. Bluish green glass. 



Exper. 181. 51 51 



3 55| 53 . . . 4& : 2 = .444. 



Min. Stove. Pale blue glass. 



Exper. 182. 53| 53-| 



3 57-| 55| . . . 3£ : l£ = .452. 



Min. Stove. Dark blue glass. 



Exper. 183. 53| 53 



3 55-| 53i . . . 2^ : i = .368. 



Min. Stove. Indigo glass. 



Exper. 184. 54^ 54 



3 59i 55£...5j|:l$=.341. 



Min. Stove. Pale indigo glass. 



Exper. 185. 53| 53£ 



3 59£ 55$ . . . 6J : 1-J = .300. 



Min. Stove. Purple glass. 



£W. 186. 5l£ 514, 



3 56| 52| . . • 4| : 14 = .270. 



Min. Stove. Violet glass. 



Exper. 187- 51 51 J 



3 55| 53 . . . 4f : 1 h = .316. It stops 684 invisible rays of heat. 



Min. Stove. Crown glass} one side rubbed on emery. 



Exper. 188. 49£ 49j This glass, so prepared, stops 775 invisible 



3 54| 50f . . . 5 : H = .225. rays of scattered heat. 



Min. Stove. Coach glass j one side rubbed on emery. 



Exper. 189. 50 50 



3 57i , 5 1| . . . 71 : 1$ = - 25 9- II sto P s 741 invisible rays of scattered heat. 



Min. Stove. Crown glass j both sides rubbed on emery. 



Exper. 190. 52 52 



3 58 53 ... 6 : 1 = .167. It stops 833 invisible rays of scattered heat 



Min. Stove. Coach glass j both sides rubbed on emery. 



Exper. 191. 52 52 



3 55| 52£ . . . 3| : £ = .231. It stops 769 invisible rays of scattered heat 



Min. Stove. Olive colour, burnt in glass. 



Exper. 192. 511 51 \ 



3 57 5Z\ . . . 5| : 2 = .364. It stops 636 invisible rays of scattered heat. 



Min. Stove. White paper. 



Exper. 193. 52 52 This substance stops only 535 invisible rays 



3 57| 54| . . . 5f : 2£ = .465 of scattered heat. 



Min. Stove. Linen. 



Exper. 194. 53| 53| 4 



3 57£ 55f . . . 4| : 24 = .543. It stops 457 invisible rays of scattered heat 



VOL. XVIII. 5 F 



This glass stops 630 invisible rays of heat. 

 It stops 524 invisible rays of heat. 

 It stops 469 invisible rays of heat. 

 It stops 632 invisible rays of heat 

 It stops 700 invisible rays of heat. 

 It stops 556 invisible rays of heat. 

 It stops 548 invisible rays of heat. 

 It stops 632 invisible rays of heat 







It stops 659 invisible rays of heat. 

 It stops 700 invisible rays of heat. 

 It stops 730 invisible rays of heat. 



