United States or Turks and Caicos Islands ? Vote for the TOP Country of the Week !
But Lord Rosse's 6-foot reflector, 54 feet focal length, constructed in 1845, is still the largest ever made. The imperfections of our atmosphere are against the use of such large apertures, unless it be on high mountains. During the last half century excellent specula have been made of silvered glass, and Dr.
Besides, the travellers now found themselves at a distance that had never before been reached by the most powerful telescopes, including even Lord Rosse's and the great instrument on the Rocky Mountains. Barbican was therefore in a condition singularly favorable to resolve the great question concerning the Moon's inhabitableness. Nevertheless, the solution still escaped him.
* Considering the fame acquired by Parsonstown from Lord Rosse's mirrors, it may be interesting to note the following extract from "The Natural History of Ireland," by Dr. Gerard Boate, Thomas Molyneux M.D., F.R.S., and others, which shows that 150 years ago Parsonstown was famous for its glass:
His personal appearance is thus described by a friend who was on terms of intimacy with him; the place is at one of Lord Rosse's conversazioni.
We know, for example, that Lord Rosse's great telescope at Parsonstown, possessing a power of magnifying 6000 times, brings the Moon to within 40 miles of us; not to speak of Barbican's great telescope on the summit of Long's Peak, by which the Moon, magnified 48,000 times, was brought within 5 miles of the Earth, where it therefore could reveal with sufficient distinctness every object above 40 feet in diameter.
This was virtually settled by Sir J. Herschel's description in 1847 of the structure of the Magellanic clouds; but it was not until Whewell, in 1853, and Herbert Spencer, in 1858, enforced the conclusions necessarily to be derived therefrom that the conception of the nebulæ as remote galaxies, which Lord Rosse's resolution of many into stellar points had appeared to support, began to withdraw into the region of discarded and half-forgotten speculations.
But in Lord Rosse's telescope you would look in vain for these glasses, and it is not at the lower end of the instrument that you are to take your station when you are going to make your observations. The astronomer at Parsonstown has rather to avail himself of the ingenious system of staircases and galleries, by which he is enabled to obtain access to the mouth of the great tube.
As there did not seem to be either air or water on its surface, the inhabitants would have a rather hard time of it, and if they went to meeting the sermons would be apt to be rather dry. If there were a building on it as big as York minster, as big as the Boston Coliseum, the great telescopes like Lord Rosse's would make it out.
I took with me only a scanty outfit of schoolbooks, with Lilly's 'Latin Grammar, and Rosse's 'View of all the Religions in the World from the Creation down to our own Times, which was shoved into my hands by my good mother as a parting present. With this small stock of letters I might have fared badly, had it not happened that my master, Mr.
Thanks to its power of penetration, the depths of the sky were explored to their utmost limits, the apparent diameter of a great number of stars could be rigorously measured, and Mr. Clarke, of the Cambridge staff, resolved the Crab nebula in Taurus, which Lord Rosse's reflector had never been able to do. It was the 22nd of November. The supreme departure was to take place ten days later.
Word Of The Day