 | James Smith - Industrial arts - 1815 - 684 pages
...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 - Natural history - 1821 - 448 pages
...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 - Industrial arts - 1825 - 396 pages
...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 - Physics - 1826 - 236 pages
...focus is to the common heat of the sun, as the area of the glass is to the area of the focus, Jllus. If a lens four inches in diameter collect the sun's...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 - New Hampshire - 1827 - 398 pages
...there is to the common heat of the sun, as the surfacn of the glass is to the surface of the focus. If a lens four inches in diameter collect the sun's...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... | |
 | Levi Washburn Leonard - Science - 1830 - 350 pages
...there is to the common heat of the sun, as the surface of the glass is to the surface of the focus. If a lens four inches in diameter collect the sun's...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... | |
 | Luke Hebert - Industrial arts - 1835 - 938 pages
...effect is so much the greater, as the surface of the lens or mirror exceeds that of the focus. Thus, if a lens four inches in diameter collect the sun's rays into a focus at the distance of one foot, the focal image will not he more than one-tenth of an inch broad. The surface of this circle... | |
 | Richard Green Parker - Physics - 1838 - 266 pages
...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...of twelve inches, the image will not be more than one tenth of an inch in diameter ; the surface of this little circle is 1600 times less than the surface... | |
 | Richard Green Parker - Physics - 1842 - 278 pages
...the urea of the glass is to the area of the focus. Thus, if a lens, four inches in diameter, cellect the sun's rays into a focus, at the distance of twelve inches, the image 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... | |
 | Richard Green Parker - 1844 - 276 pages
...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...of twelve inches, the image will not be more than one tenth of an inch in diameter; the surface of this little circle is 1600 times less than the surface... | |
| |
... 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 will not be more than one... 
