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. 1863 Excerpt: ...than at the borders. It has been conjectured that they may be hollow spherical shells, or circular flat discs, situate nearly at right angles to our line of vision. The discovery of spiral nebulae is due to Lord Rosse, being one of the results obtained with the great reflecting telescopes constructed by that nobleman. ...
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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. 1863 Excerpt: ...than at the borders. It has been conjectured that they may be hollow spherical shells, or circular flat discs, situate nearly at right angles to our line of vision. The discovery of spiral nebulae is due to Lord Rosse, being one of the results obtained with the great reflecting telescopes constructed by that nobleman. The most interesting specimen of this class is a nebula known as No. 51 of Messier's catalogue, in the constellation Canes Venatici. It presents several luminous streams running in a spiral form from a centre, and surrounded by a narrow nebulous ring. Though not clearly resolved into stars with Lord Rosse's telescope, sufficient evidence is thereby afforded that it is so composed. Other nebulae have similar spiral coils, but less distinctly marked than in the one above. Fig. 71.--Lord Rosse's Telescope, Parsonstown. The nature of the nebulous stars is involved in as great obscurity as that of the planetary nebulae. A faint nebulosity, usually of a circular figure and several minutes of arc in diameter, envelopes a star which is placed in or very near the centre: in some cases it is sharply defined at the borders, in others it gradually fades away to darkness. The stars thus attended have nothing in their appearance to distinguish them from others entirely destitute of such appendages; nor does the nebulosity in which they are situated offer the slightest indications of resolvability into stars with any telescopes hitherto constructed. As instances of nebulous stars, may be mentioned one of the fifth magnitude, numbered 55 in Andromeda, another of the same brightness, numbered 8 in Canes Venatici, and one of the eighth magnitude on the borders of Perseus and Taurus, particularly pointed out by Sir William Herschel as a remarkable object of this...
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Add this copy of An Introduction to Astronomy, to Which is Added an to cart. $59.74, good condition, Sold by Bonita rated 4.0 out of 5 stars, ships from Newport Coast, CA, UNITED STATES, published 2015 by Palala Press.
