 | Richard Green Parker - Electricity - 1856 - 502 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...1600 times greater at the focus than at the lens. 859. The following effects were produced by a large lens, or burning-glass, two feet in diameter, made... | |
 | David Ames Wells - Physics - 1859 - 468 pages
...the focus will not be more than one tenth of an inch in diameter; its surface, therefore, is 1,609 times less than the surface of the lens, and consequently the heat will be 1,600 times greater at the focus than at the lens. 681. The properties of a concave lens are greatly... | |
 | David Ames Wells - Physics - 1860 - 466 pages
...the focus will not be more than one tenth of an inch in diameter ; its surface, therefore, is 1,600 times less than the surface of the lens, and consequently the heat will bo 1,600 tunes greater at the focus than at the lens. 681 . The properties of a concave lens are greatly... | |
 | Richard Green Parker - Physics - 1861 - 488 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...1600 times greater at the focus than at the lens. 859. The following effects were produced by d, large lens, or burning-glass, two feet in diameter,... | |
 | Richard Green Parker - Physics - 1862 - 488 pages
...into a focus at the distance of twelve inches, the image will not be more than one-tenth of an injch in diameter ; the surface of this little circle is...1600 times greater at the focus than at the lens. 859. The following effects were produced by a large lens, or burning-glass, two feet in diameter, made... | |
 | Richard Green Parker - Physics - 1870 - 486 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...; the surface of this little circle is 1600 times Jess than the surface of the lens, and consequently the heat will be 1600 times greater at the focus... | |
 | David Ames Wells - 1871 - 462 pages
...the focus will not be more than one tenth of an inch in diameter; its surface, therefore, is 1,600 times less than the surface of the lens, and consequently the heat will be 1,600 times greater at the focus than at the lens. 681. The properties of a concave lens are greatly... | |
 | David Ames Wells - Physics - 1875 - 464 pages
...the focus will not be more than one tenth of an inch in diameter; its surface, therefore, is 1,600 times less than the surface of the lens, and consequently the heat will bo 1,600 times greater at the focus than at the lens. 681. The properties of a concave lens are greatly... | |
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... 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... 
