 | Leonard Dunnell Gale - Physics - 1838 - 280 pages
...in diameter collect the sun's rays into a focus at the distance of twelve inches, the image will nat be more than onetenth of an inch in diameter; the...of the lens, and consequently the heat will be 1600 limes greater at the focus than at the lens. Corollary 1. Hence the construction of common burning-glasses,... | |
 | Richard Green Parker - Astronomy - 1839 - 298 pages
...sun's rays into a focus, at the distance of twelve inches, the image will not be more than one tenth of an inch in diameter ; the surface of this little...surface of the lens, and, consequently, the heat will be 16OO times greater at the focus than at the lens, t 617. The following effects result from the laws... | |
 | Richard Green Parker - Astronomy - 1839 - 262 pages
...inches, the image will not be more than one tenth of an inch in diameter ; the surface of this h'ttle circle is 1600 times less than the surface of the...1600 times greater at the focus than at the lens, t 617. The following effects result from the laws of refraction, stated in No. 593 ; and, first, with... | |
 | Richard Green Parker - Physics - 1842 - 278 pages
...will not be more than one tenth of au inch in diameter; the surface of this little circle is IliOO times less than the surface of the lens, and, consequently,...1600 times greater at the focus than at the lens. t 617. The following effects result from the laws of refraction, stated in No. 593 ; and, first, with... | |
 | Richard Green Parker - 1844 - 276 pages
...sun's rays into a focus, at the distance of twelve inches, the image will not be more than one tenth of an inch in diameter; the surface of this little...1600 times greater at the focus than at the lens. t 617. The following effects result from the laws of refraction, stated in No. 593 ; and, first, with... | |
 | Richard Green Parker - Physics - 1849 - 418 pages
...diameter, collect the sun's rays into a focus, at the distance of twelve inches, the image will not he more than one-tenth of an inch in diameter ; the surface...1600 times greater at the focus than at the lens.* 231. The following effects result from the laws of re WITH REGARD TO CONVEX SUBFACES. 1. Parallel rays... | |
 | Education - 1849 - 206 pages
...than one-tenth =5HT5of an inch in diameter; the surface of this little Fig- 6- circle is 1600 tines less than the surface of the lens, and, consequently,...1600 times greater at the focus than at the lens. CombustiUe substances placed in the focus of such glasses are instantly coisumed; metals are melted,... | |
 | Richard Green Parker - Physics - 1850 - 408 pages
...if a lens, four inches in diameter, collect the sun's rays into a focus, at the distance of twelve inches, the image will not be more than one-tenth...1600 times greater at the focus than at the lens.* 231. The following effects result from the laws of re fraction. FACTS WITH REGARD TO CONVEX SURFACES.... | |
 | Richard Green Parker - 1852 - 620 pages
...if a lens, four inches in diameter, collect the sun's rays into a focus, at the distance of twelve inches, the image will not be ' more than one-tenth...surface of the lens, and consequently, the heat will be 1000 times greater at the focus than at the lens.* 231. The following effects result from the laws... | |
 | Richard Green Parker - Physics - 1855 - 416 pages
...Thus, if a lens, four inches in diameter, collect the sun's rays into a focus at the distance of twelve inches, the image will not be more than one-tenth...in diameter ; the surface of this little circle is 1 600 times less than the surface of the lens, and consequ ntly the heat will be 1600 times greater... | |
| |
... and, consequently, the heat at the focus is to the common heat of the sun, as the area of the glass is to the area of the focus. Thus, if a lens, four inches in diameter, collect the sun's rays into a focus, at the distance of twelve inches, the image... 
