Category: Science - Physics
The text of this book has been preserved in its original form apart from correction of two typographic errors: embarrasment → embarrassment, Cassegranian → Cassegrainian. Inconsistent hyphenation has not been altered. A lengthy preliminary section concerning the Smithsonian In...
But it must not be supposed that such apparent causes as these are required to disturb a surface injuriously. Frequently mirrors in the process for correction of spherical aberr...
4. Part 4With my mirrors of 150 inches focal length, demanding from the outset a room more than 25 feet long, this successive system had to be abandoned. It was not found feasible to pla...
6. Part 6My brother, Mr. Daniel Draper, to whose mechanical ingenuity I have on several occasions been indebted for assistance in the manifold difficulties that have arisen while constru...
7. Part 7There are only two windows, and they are near the southern angles of the roof. While they admit sunshine on some occasions, they can on others be closed, and the interior be red...
2. Part 2A short historical sketch of this telescope may not be uninteresting. In the summer of 1857, I visited Lord Rosse’s great reflector, at Parsonstown, and, in addition to an inspe...
5. Part 5The local polishers are made of lead, alloyed with a small proportion of antimony, and are 8, 6, and 4 inches in diameter, respectively. The largest and smallest are most used,...
1. Part 1The text of this book has been preserved in its original form apart from correction of two typographic errors: embarrasment → embarrassment, Cassegranian → Cassegrainian. Incons...
8. Part 8The distance of this last can be made to vary, being either two feet or twenty-eight feet from _d_. In the latter case a magnifying power of about 25 results, the moon being mad...