Vietnam or Thailand ? Vote for the TOP Country of the Week !
Updated: May 11, 2025
The latter, in the hands of the two Herschels and Rosse, had reached its utmost limits as is shown by the fact that to this day the Rosse telescope is the largest of its kind in the world. Meanwhile the production of refracting telescopes made but slow progress. As late as 1836 the largest instrument of this kind in the world was the eleven-inch telescope of the observatory at Munich.
In any telescope, whether refracting or reflecting, there are two principal parts: the part that forms the aërial images of the distant objects, and the small lens by the aid of which these images are enlarged just as if they consisted of radiating matter.
After the fiord was in shadow the level sunbeams continued to pour through the miles of bergs with ravishing beauty, reflecting and refracting the purple light like cut crystal. Then all save the tips of the highest became dead white. These, too, were speedily quenched, the glowing points vanishing like stars sinking beneath the horizon.
"Ay, he did speak of that what did he call it? Oh! 'one of the ways in which the Christian idea naturally embodied itself in imaginative minds! but the higher intellects, of course, would want fewer helps of that kind. 'They would see' ay, that was it 'the pure white light of truth, without requiring those coloured refracting media."
Let this rhomb be cut along the plane b c; and the two severed surfaces, after having been polished, reunited by Canada balsam. We learned, in our first lecture, that total reflection only takes place when a ray seeks to escape from a more refracting to a less refracting medium, and that it always, under these circumstances, takes place when the obliquity is sufficient.
Total reflection never occurs except in the attempted passage of a ray from a more refracting to a less refracting medium; but in this case, when the obliquity is sufficient, it always occurs. The mirage of the desert, and other phantasmal appearances in the atmosphere, are in part due to it.
In the case of a colored glass, a prism, or a refracting lens, we have transmissive function. The energy of the light, no matter how produced, is by the glass sifted and limited in color, and by the lens or prism determined to a certain path and shape. Similarly, the keys of an organ have only a transmissive function.
But, at the same time, it was not fair to circumstances or to people to have a false sentimentality woven into what was written. Things ought to have been looked upon through the eyes of common sense and not through the refracting glasses of the indignation of the moment.
Farther on, you meet with a camera obscura, whose effect surprises the spectators the more, as the objects represented within it have the motion which they do not find in common optics. There, you see a double refracting telescope: for two sous, you enjoy its effect.
Hopkinson, I mentioned to him that the Abbe Rochon, who discovered the double refracting power in some of the natural crystals, had lately made a telescope with the metal called platina, which, while it is as susceptible of as perfect a polish as the metal heretofore used for the specula of telescopes, is insusceptible of rust, as gold and silver are.
Word Of The Day
Others Looking