The Railway Locomotive; What It Is and Why It Is What It Is (Paperback)

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. 1908 Excerpt: ...pressures, which are 14-73 lbs. higher. The heat produced by the combustion of the coal in the firebox has to be transferred to the water in the boiler, and to do this it must pass through the metal of the plates and tubes. Precisely how the transmission takes place is not known. In effect, the side of the plate next the fire is made hotter than the side of the plate next the water, and heat goes through; the water side of the plate being in Ap L turn hotter than the water, the transmission con tinues. This is all apparently very simple, but the process is really complex. It is assumed that the plate resists the trans-B mission of heat through its substance, and that the fact that one material is a better conductor to of heat than another is due to variation in the amount of the resistance. Hence, we find it TM argued that copper plates being much better 1IG' 56" conductors of heat than iron or steel, they are preferred by astute railway engineers to steel or iron plates. There is, however, no basis of truth in this theory. Steel fire-boxes are almost always used in the United States. They have been tried in this country. Careful experiments, and indeed long-continued practical trials, show that copper possesses no advantage whatever over iron or steel. It is used because it is much more durable than any other material; and when a copper fire-box is worn out it can be sold as old metal at from 50Z. to 701. a ton, according to the state of the market, while an old steel fire-box will hardly pay the cost of breaking it up. The efficiency of a fire-box plate does not in practice depend on its conducting powers at all. It does depend on its receiving and emitting powers. It has been shown by Peclet and others that a square inch o copper in a fire-box...