The results of the tests of ductility which are here given, with reference to the cupro-manganese, manganese bronze, the alloys with zinc and tin, are taken from M.C. Hensler’s very valuable communication to the Berlin Society for the Advancement of the Industrial Arts.
These various alloys, as well as the phosphorus bronze, of which we make no mention here, are at present very largely used in the manufacture of technical machines, as well as for supports, valves, stuffing-boxes, screws, bolts, etc., which require the properties of resistance and durability. They vastly surpass in these qualities the brass and like compounds which have been used hitherto for these purposes.—Bull. Soc. Chim., Paris, xxxvi. p. 184.
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THE ECONOMICAL WASHING OF COAL GAS AND SMOKE.
In a recent number of the Journal des Usines a Gaz appears a note by M. Chevalet, on the chemical and physical purification of gas, which was one of the papers submitted to the Societe Technique de l’Industrie du Gaz en France at the last ordinary meeting. This communication is noticeable, apart from the author’s conclusions, for the fact that the processes described were not designed originally for use in gas manufacture, but were first used to purify, or rather to remove the ammonia which is to be found in all factory chimneys, and especially in certain manufactories of bone-black, and in spirit distilleries. It is because of the success which attended M. Chevalet’s treatment of factory smoke that he turned his attention to coal gas. The communication in which M. Chevalet’s method is described deals first with chimney gases, in order to show the difficulties of the first class of work done by the author’s process. Like coal gas, chimney gases contain in suspension solid particles, such as soot and ashes. Before washing these gases in a bath of sulphuric acid, in order to retain the ammonia, there were two problems to be solved. It was first of all necessary to cool the gases down to a point which should not exceed the boiling-point of the acid employed in washing;