| Sir Richard Phillips - 1807 - 182 pages
...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
...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... | |
| Edward Augustus Kendall - 1811
...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
...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 - 152 pages
...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... | |
| Jeremiah Joyce - 1815
...the former magnifies 48 times, and the latter 20O times. Tutor. Refracting telescopes for. vie wing **terrestrial objects, in order to show them in their...eye-glasses. We have now said as much on the subject as is** nesessary to our plan. Charles. What is the construction of operaglasses, that are so much used at... | |
| George Gregory - 1820
...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... | |
| Jeremiah Joyce - 1825
...constructed in this way, as you did in the last? Tutor. Yes; the three glasses next the eye baving **their focal distances equal, the magnifying power...operaglasses, that are so much used at the theatre** J Tutor. The opera-glass is nothing more than a short refracting telescope. The night telescope is... | |
| Sir Richard Phillips - 1826 - 214 pages
...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 - 318 pages
...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... | |
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