81 g Transactions of the American Institute. 



Hence the evaporating capacity was proved to be 17.20 per cent in 

 fovor of the steel boiler. One pound of coal evaporated iu the iron 

 boiler 6,350 pounds of water, and in the steel boiler 7,4G7 pounds 

 of water at 100 decrees C. 



At the next trial the whole operation was performed in the same 

 manner, only the velocity of the escaping steam was less. It 

 resulted in showing 19.62 per cent in favor of the steel boilen 

 One pound of coal evaporated in the iron boiler 5,809 pounds, and 

 iu the steel boiler 7,008 pounds of water. 



These two experiments were verified in the following manner: 

 To an equal quantity of feed-water in each boiler an equal volume 

 of a strong solution of salt was added. After stirring the water 

 for some time, by means of long poles, and boiling it with closed 

 man-holes, samples were taken out for future analysis. On com- 

 pleting this experiment in which equal quantities of fuel and water 

 were used, further samples were taken out. The analysis of the 

 samples by Dr. List, of Hagen, showed that in the iron boiler one 

 quart of water contained before evaporation 4,627 grammes of 

 chloride of sodium, and after 5,985; in the steel boiler one quart 

 contained 4,371 grammes before, and 7,385 gi-ammes of salt after 

 evaporation; the iron boiler lost 33.76 quarts, and the steel boiler 

 40.81 quarts of water, shoAving 20.85 per cent in fovor of the latter. 

 The average per centage of these three experiments is 19.24 per 

 »>ent in favor of the steel boiler, which it will be noted had a shell 

 thirty-three per cent thinner than that of the wrought-iron boiler. 



As usual, considerable discussion followed the reading of these 

 icientific items, the most being said regarding steel, and the peculiar 

 properties of tungsten as a component of steel. 



Dr. Vanderweyde exhibited a tungsten steel knife of very ordi* 

 ■jiary pattern, and proved its power of cutting glass. A question 

 was started respecting the truth of the statement that a Paris chemist 

 had succeeded in giving to charcoal the diamond property of cutting 

 glass. Prof. Joy stated that it was true to a certain extent, but 

 that it had been accomplished only at an outlay of time and money, 

 which would make the charcoal more expensive than the native 

 diamond. 



WROUGHT raON RAILWAY CAR. 



Mr. La Moth exhibited a cross section of a metallic passenger 

 car. Its chief merit seems to be its pccular construction, for which 

 tubes are used, instead of bars, and which are curved at the corners, 

 and not bent at right angles. Its claim was for great durability, 



