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Updated: May 1, 2025
Translator. It would appear that Hooke had conjectured that the figure of the earth might be spheroidal before Newton or Huyghens turned their attention to the subject.
These telescopes were all made with a convex object-glass and a concave eye-lens, and this type is spoken of as the Galilean telescope. Its defects are that it has no real focus where cross-wires can be placed, and that the field of view is very small. Kepler suggested the convex eye-lens in 1611, and Scheiner claimed to have used one in 1617. But it was Huyghens who really introduced them.
The law of falling bodies disclosed by Galileo; that of the composition of forces also disclosed by Galileo; and that of centrifugal force found out by Huyghens all of them generalisations of terrestrial physics. Yet, with facts like these before him, M. Comte places astronomy before physics in order of evolution!
Nevertheless this great theory of undulation, like many another truth, which in the long run has proved a blessing to humanity, had to establish, by hot conflict, its right to existence. Illustrious names were arrayed against it. It had been enunciated by Hooke, it had been expounded and applied by Huyghens, it had been defended by Euler. But they made no impression.
They skirt the western shores of the Mare Imbrium, over which they rise in immense cliffs, 18 or 20 thousand feet in height, steep as a wall and casting over the plain intensely black shadows at least 90 miles long. Of Mt. Huyghens, the highest in the group, the travellers were just barely able to distinguish the sharp angular summit in the far west.
The early recognition Spinoza received from men like Henry Oldenburg, the first secretary of the Royal Society, from Robert Boyle and Huyghens, was hardly adequate recompense for the fine dust he ground which aggravated his inherited tuberculosis and undoubtedly considerably hastened his death. Spinoza's accomplishment in his chosen trade was not merely practical.
No sooner were these discoveries given to the world than they were opposed with a degree of virulence and ignorance which have seldom been combined in scientific controversy. The most distinguished of his opponents were Robert Hooke and Huyghens. Both attacked his theory from the standpoint of the undulatory theory of light which they upheld. II. The Colours of Natural Bodies
It was not until 1656 that Huyghens, in his small pamphlet De Saturni Luna Observatio Nova, was able to suggest in a cypher the ring form; and in 1659, in his Systema Saturnium, he gave his reasons and translated the cypher: "The planet is surrounded by a slender flat ring, everywhere distinct from its surface, and inclined to the ecliptic."
'Were it not for my courage and enterprise, I cried, 'this phenomenon would have remained a secret of the Nature that gave birth to it. She yields her treasures to such only as fear not. "I had read in a book of Huyghens, Guinand, Newton, Herschel the great high-priests of science who had striven through patient years to read the hieroglyphics of the heavens. 'The wise imbeciles, I thought.
In the seventeenth century telescopes were made of great length, going up to 300 feet. Huyghens also invented the compound eye-piece that bears his name, made of two convex lenses to diminish spherical aberration. But the defects of colour remained, although their cause was unknown until Newton carried out his experiments on dispersion and the solar spectrum.
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