Triumphs and wonders of the 19th century, the true mirror of a phenomenal era, a volume of original, entertaining and instructive historic and descriptive writings, showing the many and marvellous achievements which distinguish an hundred years of material, intellectual, social and moral progress .. . 94 TRIUMPHS AND WONDERS OF THE XIX™ CENTURY Analysis in bringing to our earthly laboratories the work of the DivineHand performed in distant regions of space. Yet the story of the spectro-scope is easily told. In its essential elements it is merely this : A ray oflight, entering a darkened room t
Triumphs and wonders of the 19th century, the true mirror of a phenomenal era, a volume of original, entertaining and instructive historic and descriptive writings, showing the many and marvellous achievements which distinguish an hundred years of material, intellectual, social and moral progress .. . 94 TRIUMPHS AND WONDERS OF THE XIX™ CENTURY Analysis in bringing to our earthly laboratories the work of the DivineHand performed in distant regions of space. Yet the story of the spectro-scope is easily told. In its essential elements it is merely this : A ray oflight, entering a darkened room through a hole in the window shutter, pro-duces a bright beam on the opposite wall. A triangular glass prism heldclose to the crevice turns this beam into a band of rainbow hues. If thehole can be changed into a small slit, say one fourth of an inch high and onefiftieth of an inch Avide, and if the light can further be made to pass in suc-cession through several prisms, instead of through one, the band will be soelongated thereby that its various and surprising markings can be thoroughlytraced and fully studied. To this band of bright colors Sir Isaac Newton gave the name of the. THE SPECTROSCOPE. solar spectrum. The image formed by the light of any luminous body,after it has passed through a prism, is said to be the spectrum of that body. VIII. THE SPECTROSCOPE AND ITS TRIUMPHS. The spectroscope consists essentially of three tubes joined in the form ofthe letter Y, one of which is a small telescope, in the focus of which anarrow slit is placed to admit the ray of light that is to be examined;a prism, or a ruled grating that disperses the light, so as to form a spec-trum ; and a view telescope, with which to observe the various parts of thespectrum. By using a small telescope to view the spectrum of the sun, Fraunhofer, aGerman optician, in 1814, discovered that the whole length of the spectrumwas crowded with dark lines, very narrow, indeed, but scattered all throughthe seven
Size: 1576px × 1586px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, bookidtri, booksubjectinventions
