 | Edward Augustus Kendall - 1811 - 516 ページ
...the sun'S rays hito a footn at the distance of 12 inches, the Image will not be ftiore than one tenth of an inch in diameter, the surface of this little...surface of the lens, and consequently the heat will be KiOO times greater at the focus than at the lens. Hence the construction of Common burning glasses,... | |
 | James Smith - 1815 - 684 ページ
...into a focus at the distance of one foot, the image will not be more than one-tenth of an inch broad. The surface of this little circle is 1600 times less...than the surface of the lens, and consequently the density of the sun's rays within it is proportionately increased. It is not therefore Bunting lenses... | |
 | Alexander Jamieson - 1821 - 448 ページ
...into a focus at the distance of one foot, the mage will not be more than one-tenth of an inch broad. The surface of this little circle is 1600 times less...than the surface of the lens, and consequently, the sun's rays must be ten times den 324. If the rays of the sun dispersed over the surface of a glass,... | |
 | Luke Herbert - 1825 - 396 ページ
...into a focus at the distance of one foot, the image will not be more than one tenth of an inch broad. The surface of this little circle is 1600 times less...than the surface of the lens, and consequently, the sun's rays must be ten times denser within that circle ; it is not therefore surprising that it burns... | |
 | Sir Richard Phillips - 1826 - 254 ページ
...//IKS. 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...times greater at the focus than at the lens. Cor. I. Hence the construction of common burning-glasses, which are all double convex lenses. 2. Hence the... | |
 | Sir Richard Phillips - 1826 - 236 ページ
...Jllus. 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...diameter, the surface of this little circle is 1600 limes less than the surface of the lens, and consequently the heat will be 1600 times greater at the... | |
 | Levi Washburn Leonard - 1827 - 398 ページ
...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 circle is one thousand six hundred times less than the surface of the lens, and consequently the heat will be... | |
 | Levi Washburn Leonard - 1830 - 350 ページ
...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 circle is one thousand six hundred times less than the surface of the lens, and consequently the heat will be... | |
 | Leonard Dunnell Gale - 1838 - 308 ページ
...Illustration. 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 onetenth of...1600 times greater at the focus than at the lens. Corollary 1. Hence the construction of common burning-glasses, which are all double-convex lenses.... | |
 | Richard Green Parker - 1838 - 266 ページ
...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... | |
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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... 
