 | Sir Richard Phillips - 1807 - 212 頁
...three eye glasses have all their focal distances equal, and the magnifying power is found as before, by dividing the focal distance of the object-glass by the focal distance of one of the eye-glasses. 277- The camera obscura is made by fixing a convex glass in a hole of a window shutter, and if no light... | |
 | George Gregory - 1808 - 452 頁
...the image may be seen upright. The magnifying power of this, which is called the dioptric telescope, is found by dividing the focal distance of the object-glass by the focal distance of the eye-glass, and the quotient expresses the magnifying power. The greatest inconvenience attending... | |
 | Jeremiah Joyce - 1809 - 290 頁
...that the former magnifies 48 times, and the latter 200 times. Tutor. Refracting telescopes for viewing terrestrial objects, in order to show them in their...eye-glasses. We have now said as much on the subject as is necessary to our plan. Charles. What is the construction of opera-glasses, that are so much used at... | |
 | Edward Augustus Kendall - 1811 - 476 頁
...glasses ef, gh, and t k. The three «ye.glasses have all their focal distances equal, and .therefore the magnifying power is found by dividing the focal...distance of the object-glass by the focal distance of either of the eye-glasses. The reflecting telescope may be thus described : Jet ab tig. 31, be a distant... | |
 | Edward Augustus Kendall - 1811 - 462 頁
...glasses « f, gh, and > k. The three eyeglasses have all their focal distances equal, and therefore the magnifying power is found by dividing' the focal distance of the object-glass by the focal diftance of either of the eye-glasses. The reflecting telescope may be thus described : let ab fig.... | |
 | Sir Richard Phillips - 1811 - 196 頁
...three eye-glasses have all their focal distances equal, and the magnifying power is found, as before, by dividing the focal distance of the object-glass by the focal distance of one ot the eye-glasses. 275. The camera obscura is made by fixing a convex glass in a hole of a window... | |
 | George Gregory - 1820 - 458 頁
...the image may be seen upright. The magnifying power of this, which is called the dioptric telescope, is found by dividing the focal distance of the object-glass by the focal VOL. I. K distance of the eye-glass, and the quotient expresses the magnifying power. The greatest... | |
 | Sir Richard Phillips - 1826 - 236 頁
...three eye-glasses have all their focal distances equal, and the magnifying power is found as before, by dividing the focal distance of the object-glass by the focal distance of one of the eye-glasses. 195. Galileo's telescope consists of a convex objectglass'and a concave eye-glass,so placed that the... | |
 | Levi Washburn Leonard - 1827 - 398 頁
...will appear in an inverted position. The three eye-glasses have all their focal distances equal, and the magnifying power is found by dividing the focal...object-glass by the focal distance of one of the eye-glasses. The two additional lenses THE TELEGRAPH. 87 are not necessary for astronomical telescopes ; for no... | |
 | Levi Washburn Leonard - 1830 - 350 頁
...will appear in an inverted position. The three eye-glasses have all their focal distances equal, and the magnifying power is found by dividing the focal...object-glass by the focal distance of one of the eye-glasses. The two additional lenses *HE TELEGRAPH. 87 are not necessary for astronomical telescopes ; for no... | |
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Yes ; the three glasses next the eye having their focal distances equal, the magnifying power is found by dividing the focal distance of the object-glass by the focal distance of one of the eye-glasses. 
