 The force to keep up the momentum of a body moving in a horizontal plane in the air (in which there is so little friction) cannot be great, and this force is all that is wanted. The movement of the neck and body of the condor, we must suppose, is sufficient...  The Illustrated Natural History: Birds - Pàgina 15per John George Wood - 1862 - 2396 pàginesVisualització completa - Sobre aquest llibre
 | Railway readings - 1847 - 172 pàgines
...The propelling force in their motion is greatly derived from the head and neck. It is truly wonderful to see so great a bird, hour after hour, without any...exertion, wheeling and gliding over mountain and river. (Darwin^ South America.) Poison of Vipers.—Mr. Humboldt has observed, that in the recent experiments... | |
 | Philip Henry Gosse - 1849 - 344 pàgines
...this force is all that is wanted. The movement of the neck and body of the Condor, we must suppose, is sufficient for this. However this may be, it is truly...exertion, wheeling and gliding over mountain and river." Mr. Darwin supposes that the Condor breeds only once in two years, that it lays two large white eggs... | |
 | William Dowling - 1849 - 356 pàgines
...if the extended wings formed the fulcrum on which the movements of the neck, body, and tail acted. It is truly wonderful and beautiful to see so great...exertion, wheeling and gliding over mountain and river." It is only recently that the true history of the condor has become known, many wild tales having been... | |
 | Aeronautical Society of Great Britain - 1883 - 488 pàgines
...this force is all that is wanted. The movement of the neck and body of the condor, we must suppose, is sufficient for this. However this may be, it is truly...exertion, wheeling and gliding over mountain and river." So far as the soaring birds are concerned the case might rest here. Observe that the strongest and... | |
 | Albert Taylor Bledsoe, Sophia M'Ilvaine Bledsoe Herrick - 1870 - 512 pàgines
...this force is all that is wanted. The movement of the neck and body of the condor, we must suppose, is sufficient for this. However this may be, it is truly...exertion, wheeling and gliding over mountain and river.' He says also that 'the head and neck were moved frequently, and apparently with force.' Recognizing,... | |
 | 1875 - 232 pàgines
...the fulcrum on which the movements of the neck, body, and tail, acted. . . . It is truly wonderful to see so great a bird, hour after hour, without any...exertion, wheeling and gliding over mountain and river.' ' Some old writers have affirmed,' says Tschudi, ' that the plumage of this bird is invulnerable to... | |
 | Charles Darwin - 1876 - 586 pàgines
...this force is all that is wanted. The movement of the neck and body of the condor, we must suppose, is sufficient for this. However this may be, it is truly...wonderful and beautiful to see so great a bird, hour afker hour, without any apparent exertion, wheeling and gliding over mountain and river. April 29t!t.... | |
 | Charles Darwin - 1879 - 452 pàgines
...the rapid descent seemed to urge the bird upward with the even and steady movement of a paper kite. It is truly wonderful and beautiful to see so great...wheeling and gliding over mountain and river. THE OSTRICH. ON the fine plains of turf in Banda Oriental we saw many ostriches (Struthio rli,ea). Some... | |
 | Charles Darwin - 1889 - 628 pàgines
...this force is all that is wanted. The movement of the neck and body of the condor, we must suppose, is sufficient for this. However this may be, it is truly...exertion, wheeling and gliding] over mountain and river. April 29th. — From some high land we hailed with joy the white summits of the Cordillera, as they... | |
 | 1891 - 604 pàgines
...force is all that is wanted.. The movement of the neck and body of the condor, we must suppose, is sufficient for this. However this may be, it is truly...wheeling and gliding over mountain and river." The above remarkable words for many years have served to sustain my interest in the endeavor to substitute... | |
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