770 



SCIENCE. 



[Vol. II., No. 4.". 



ENGINEERING. 

 Honigman's fireless locomotive. — Mr. Honig- 

 raan constructs an engine in which the steam is sup- 

 plied by evaporation from a charge of water which is 

 furnished to the boiler at the station, and there 

 brought up to the required temperature and pressure. 

 The shell of the boiler is surrounded by, or may en- 

 close, another vessel, between which and the boiler a 

 narrow space is left, which is filled with caustic soda. 

 The exhaust-steam is discharged Into this mass of 

 soda, which at once absorbs it; and the absorption 

 gives rise to a large amount of heat, which is in turn 

 given out, and returned to tlie water in the boiler, 

 where it produces an additional quantity of steam; 

 and the latter, being exhausted into the compartment 

 containing soda, gives rise to additional quantities 

 of heat; and thus the process is continuous, and 

 the locomotive continues to exert its power, until the 

 solution of soda becomes so far saturated that it can 

 no longer take up the exhausted steam, and supply 

 heat to the boiler, with sufficient rapidity to enable the 

 engine to do its work. When this state of affairs is 

 reached, the engine is recharged, and is again sent out 

 on the line. The soda removed from the exhausted 

 engine is placed in an evaporator and deprived of its 

 moisture, and is then again ready for further service. 

 This seems to be the first attempt to make practical 

 application of the now well-known principle discov- 

 ered by Faraday sixty years ago, and probably even 

 earlier known on the continent of Europe. It is re- 

 ported to be tolerably successful, and likely to have 

 practical use where the presence of a fired engine is 

 notpermissible. — (io?id. engineering, Aug.) li. ir. t. 



[474 

 Compound locom.otives in Europe. — Mr. Bor- 

 ries has read a paper before the Union of German 

 engineers, relating the progress of the compound en- 

 gine on German railways. They were first intro- 

 duced by A. Mallet of Paris. There are now forty 

 of these engines at work. They are worked either 

 simple or compound, as desired. They are economi- 

 cal, and may be worked with a wide variation in the 

 amount of power developed, but are somewhat com- 

 plicated, do not distribute the steam in the manner 

 sometimes found practically desirable in working, and 

 the action of the steam during compression leaves 

 something still to be desired. Mr. Borries has en- 

 deavored to obtain a system which should permit the 

 use of double expansion at all times, should be sim- 

 ple, and should permit the proper adjustment of the 

 ratio of expansion at any time, if possible. At start- 

 ing, steam is admitted to both cylinders, reaching the 

 large engine-cylinder through a ' reducing-valve; ' 

 but, after starting, the machine works as a compound 

 engine. At all points of cut-off, he gets nearly equal 

 work done in each cylinder. The engine works easily, 

 and no spark-arrester is needed. The excess of weight 

 and cost is about four per cent above that of other 

 engines: the gain in power is six per cent, and in 

 economy of fuel nine and a half per cent. The en- 

 gine is considered a success. The best results are 

 reported from passenger-engines thus constructed. — 

 {Land, engineering, Aug.) r. h. t. [475 



Finishing rails. — M. Oazan writes lo La niHnl- 

 lurgie, saying that the chemical composition of the 

 steel has very little to do with the strength of the rail : 

 it depends more upon the temperature at which the 

 rail is finished in the mill. Those finished at a high 

 red heat, and which are recognizable by their blue 

 tint, are more brittle and weaker than those which 

 are finished at a lowei- heat. The latter arc usually 

 covered with a reddish colored layer of oxide. In the 

 former case the fracture exhibits a granular, and in 

 the latter case a good steely, surface. M. Gazan thinks. 

 that, in the former case, time is allowed for the for- 

 mation of crystals which cannot be produced in the 

 latter. If the red-hot metal he worked until it has 

 fallen below the red heat, it does not exhibit crystal- 

 lization. — {Itailway rev., Sept. 8.) r. h. t. [476 



Compound engines and boilers. — Mr. M. Cor- 

 yell, a member of the U. S. naval advisory board, 

 writes that good results have been obtained from 

 recent compound engines! Pressures rarely exceed 

 100 pounds per square inch (8 atmos. nearly, absolute 

 pressures); but he thinks 150 (11 atmos., absolute) 

 can be carried by adopting, instead of the 'Scotch 

 boiler,' a boiler of but 6 feet diameter (1.8 metres), 

 with cylindrical shell and set in brick-work, — apian 

 of which great distrust has hitherto been felt by en- 

 gineers. He suggests a still better scheme, however, 

 — a water-tube ' sectional ' boiler, safe for 200 pounds. 

 This would permit fire-sui-faces of but a quarter-inch 

 (0.6 centimetre) ii-ou. The use of fire-brick furnace- 

 walls is found to give some economy of fuel. He has 

 found high pressures and great expansion to give 

 good results, and states that at least one successful 

 designer would exceed 20 expansions, — a proposal 

 which is not looked upon with favor by leading en- 

 gineers. Mr. Coryell would use the beam-engine for 

 screw-ships on account of its perfect balance. He 

 states that engines of 6 feet stroke are in use, making 

 60 revolutions per minute with 00 pounds (5 atmos.) 

 of steam and a cut-off at .5 inches (i.e., a ratio of ex- 

 pansion of 14.4), and that these engines have been in 

 successful use for nine years, making voyages of five 

 days without detention and with economy. Engines 

 of 88 inches (2.23.J metres) stroke have averaged 58, 

 and have sometimes made 71, revolutions per minute. 

 He thinks 4 feet (1.22 metres) the shortest advisable 

 stroke for marine engines, and believes that twice 

 that length will ultimately become common. — {Mech. 

 eng., Sept. 20.) R. H. T. [477 



CHEMISTRY. 

 {Gcnentl, phydcal, and inorganic.) 

 Active oxygen. — For the purpose of testing the 

 accuracy of his conclusion relating to the action of 

 moist phosphorus on carbonic oxide, which seemed to 

 be disproved by the results of Kemsen and Kaiser " 

 (Science, i. 704), E. Baumann has repeated his ex- 

 periments, using apparatus closed with glass stoppers, 

 and taking every precaution to avoid contact of the 

 gases with organic matter of any kind. In one experi- 

 ment, seven hundred cubic centimetres of carbonic 

 oxide, diluted with air, after passing through the ap- 

 paratus, in fifteen hours gave 36.6 milligrams of 



