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. 1914 edition. Excerpt: ...extend beyond A. 1750. The observations have been often repeated with various samples but always with the same result. Handke has confirmed this observation. The factor which determined the extreme ultra-violet limit of the spectrum as obtained by Schumann was the absorption of the clear, colourless fluorite ...
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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. 1914 edition. Excerpt: ...extend beyond A. 1750. The observations have been often repeated with various samples but always with the same result. Handke has confirmed this observation. The factor which determined the extreme ultra-violet limit of the spectrum as obtained by Schumann was the absorption of the clear, colourless fluorite which formed the lenses and prisms of his apparatus. This fact was demonstrated with the vacuum grating spectroscope, for with this instrument it was possible to extend the spectrum considerably by removing all fluorite from the light-path. The phenomenon is illustrated in Plate II, "Astrophysical Journal," 23, p. 205. Without fluorite the limit of the spectrum in this plate lies near 1030; with fluorite it is cut off at 1230. Very recently the spectrum has been pushed to X 905. Though clear, colourless fluorite is rare and expensive, the coloured varieties are common enough, and sometimes may be obtained in clear masses of considerable size. Stokes1 examined one coloured specimen that showed considerable transparency in the region of 1850. Specimens cut from purple, green, pink, and yellow fluorite of various shades have been tested both with the grating spectroscope and with the cruder prism-mirror apparatus. They were usually in the form of plates from 1 to 2 mm. thick. They show considerable range of transparency. A typical spectrum taken through a purple fluorite terminates abruptly at X 1700. Of fifty-seven specimens, forty-two were less transparent than this purple sample, 1" Collected Works," IV, p. 221. ten were nearly equal to quartz I mm. thick, and five were almost as good as colourless fluorite from Zeiss. From this test it appeared that the depth of colour was a good indication of the absorption; the most...
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Add this copy of The Spectroscopy of the Extreme Ultra-Violet to cart. $71.85, good condition, Sold by Bonita rated 4.0 out of 5 stars, ships from Newport Coast, CA, UNITED STATES, published 2015 by Palala Press.
