tag="{http://www.w3.org/1999/xhtml}a">The Sherman Process

183 Rubber Tires for Traction Engines 183 Central Shaft of the Hoosac Tunnel 184 A Museum of Art and Natural History 184 Report of Judges, American Institute Fair.—The Allen Engine 184 Lyceum of Natural History 184 Warming and Ventilating Railroad Cars 184 The Mineral Resources of Missouri 185 Scientific Intelligence 185 American Institute of Mining Engineers 185 Consumption of Sugar, Coffee, and Tea 185 Unpleasant Discovery in the Patent Office 185 Substitute for Albumen in Photography   185 Louisiana State Fair 185 Test for Purity of Water 185 New Books and Publications 185 Business and Personal 186 Answers to Correspondents 186 Applications for the Extension of Patents 186 Recent American and Foreign Patents 187 Queries 187 Inventions Patented in England by Americans 187 List of Patents 187

---

THE INFLUENCE OF INTENSE COLD ON STEEL AND IRON.

---

[Condensed from Nature.]

---

There has recently been a most interesting discussion at the Literary and Philosophical Society, Manchester, on the above subject.

The paper which gave rise to the discussion was by Mr. Brockbank, who detailed many experiments, and ended by stating his opinion that iron does become much weaker, both in its cast and wrought states, under the influence of low temperature; but Mr. Brockbank's paper was immediately followed by others by Sir W. Fairbairn, Dr. Joule, and Mr. Spence, which at once put an entirely new complexion on the matter.

Dr. Joule says:

"As is usual in a severe frost, we have recently heard of many severe accidents consequent upon the fracture of the tires of the wheels of railway carriages. The common-sense explanation of these accidents is, that the ground being harder than usual, the metal with which it is brought into contact is more severely tried than in ordinary circumstances. In order apparently to excuse certain railway companies, a pretence has been set up that iron and steel become brittle at a low temperature. This pretence, although put forth in defiance, not only of all we know, of the properties of materials, but also of the experience of everyday life, has yet obtained the credence of so many people that I thought it would be useful to make the following simple experiments:

"1st. A freezing mixture of salt and snow was placed on a table. Wires of steel and of iron were stretched, so that a part of them was in contact with the freezing mixture and another part out of it. In every case I tried the wire broke outside of the mixture, showing that it was weaker at 50° F., than at about 12° F.

"2d. I took twelve darning needles of good quality, 3 in. long, ¹⁄24 in. thick. The ends of these were placed against steel props, 2⅛ in. asunder. In making an experiment, a wire was fastened to the middle of a needle, the other end being attached to a spring weighing-machine. This was then pulled until the needle gave way. Six of the needles, taken at random, were tried at a temperature of 55° F., and the remaining six in a freezing mixture which brought down their temperature to 12° F. The results were as follow:—