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. 1912 Excerpt: ...the maintenance labor can be more efficiently organized when a great many lamps of a kind are to be cared for than when the number of lamps is small. The maintenance cost in the table refers to two or three or four thousand hours use per year. When lamps are used only a few hundred hours per year the maintenance is ...
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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. 1912 Excerpt: ...the maintenance labor can be more efficiently organized when a great many lamps of a kind are to be cared for than when the number of lamps is small. The maintenance cost in the table refers to two or three or four thousand hours use per year. When lamps are used only a few hundred hours per year the maintenance is more expensive per hour. (f) Color.--When whiteness of light is a necessity, it is of course meaningless to compare the cost of carbon-arc lamps and tungsten lamps with the cost of flame-arc lamps and mercuryvapor lamps. See Art. 76. 72. Lamp globes, shades and reflectors.--Let one consider the lamps which one sees everywhere, on city streets, in stores and public halls, and in residences, and one will realize that lamps are almost universally equipped with shades and reflectors. These shades and reflectors are used for three distinct purposes, namely, (a) to eliminate glare, f (b) to throw the light in a desired direction, and (c) for decoration. The use of a shade for the elimination of glare is exemplified by the opal and ground glass globes which enclose indoor arc lamps and Welsbach gas lamps, and the use of a shade for throwing the light of a lamp in a desired direction is exemplified by the canopy reflectors commonly used on street lamps. In most cases shades and reflectors are used for the double purpose of eliminating glare and directing the light from a lamp. See Cravath and Lansingh, Practical Illumination, pages 25-135, McGraw Publishing Company, 1907. The results of an extensive series of experimental studies of globes and reflectors by R. B. Williamson and J. H. Klinck are given in Journal of Franklin Institute, Vol. CXLIX, page 66, 1900. Also see papers by V. R. Lansingh, Transactions of Illuminating Engineering Society, Vol. II, pa..
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Add this copy of Electric Lighting and Miscellaneous Applications of to cart. $47.02, new condition, Sold by Revaluation Books rated 4.0 out of 5 stars, ships from Exeter, DEVON, UNITED KINGDOM, published 2009 by BiblioBazaar.
Add this copy of Electric Lighting and Miscellaneous Applications of to cart. $47.02, new condition, Sold by Revaluation Books rated 4.0 out of 5 stars, ships from Exeter, DEVON, UNITED KINGDOM, published 2009 by BiblioBazaar.
