The Observatory Volume 4

The Observatory Volume 4

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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1881 edition. Excerpt: ... however, we need not have remained so long in doubt on a matter of this kind, because, as early as 1869 observations were made which showed that when the Sun is in an excited condition iron vapours are among those vapours which show their motion by a change of refrangibiSty. So that we had the opportunity of learning whether these really were identical bells, so to speak, being struck in different ways. I think you will acknowledge that if we are dealing with bells struck in different ways, however much the spectrum may vary, the molecules should be going with the same velocity. We found, however, when we came to make these observations, that the bells were going with different velocities; so that it cannot, by any possibility, be the same bells which on being struck give us those various notes. In another part of the spectrum these motions have been observed with very much greater success, for the reason that in that other part there are more lines which are observed to indicate considerable motion in Sun-spots. Limiting our observations to lines visible in the same field of view and at the same moment of time, it it a mere toss-up which line of iron shows a descending motion of 30 miles a second, and which line of iron does not move at all, either up or down; so that I think we are justified, so far as these observations go, in considering that there is great probability in favour of the view that we have in these lines, seen in spots and storms, the lines due to the constituents of iron, and not to iron itself, which are competent to resist the transcendental dissociating energies of these hotter parts of the Solar atmosphere. If so, we can bring it to the test; for if we accept any theory of evolution at all, we must imagine that, as our own...
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Product details

  • Paperback | 144 pages
  • 189 x 246 x 8mm | 268g
  • Miami Fl, United States
  • English
  • black & white illustrations
  • 1236529545
  • 9781236529541