PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. 4:1*7 



luble silicate of lime. It has been adopted in one of the pre- 

 liminary operations in preparing cotton cloth for printing. It is 

 suggested that it be used in manufacturing brick to make them 

 hard. 



Dr. Yanderweyde exhibited specimens of soluble glass, and 

 suggested that it should be made soluble in boiling water, but 

 insoluble in cold water, so that in its application there should be 

 no danger of its being washed off. If mingled Avith clay, it 

 would probably form a silicate of aluminum, and make an 

 impenetrable brick. The soda would be washed away. 



Subject for discission. — The subject selected for the next 

 meeting was, " Textile Fabrics." 

 Adjourned for two weeks. 



American Institute, Polytechnic Association, ? 



January 9, 18G2. ) 

 Prof. Cyrus Mason in the chair. 



, , NEW COAL oil LAMP. 



Mr. Dibben exhibited and explained a new coal oil lamp, 

 invented by C. W. Smith, for burning coal oil without a chimney. 

 This lamp burns two fluids in the same flame — alcohol and coal 

 oil. The latter is always uppermost in consequence of its less 

 specific gravity, and they are not so easily mixed as to influence 

 the result. One wick reaches to the bottom of the lamp, taking 

 tip the alcohol, and the other is floated by a cork so as to take up 

 the coal oil. Coal oils are so rich in carbon that they cannot .be 

 burned alone with an ordinary wick without an argand chimney. 

 In this lamp, now before us, the flame of the alcohol, furnishes 

 the best requisite for the complete combustion of the carbon 

 of the coal oil, and surrounds the flame from the coal oil, 

 so as to prevent smoking. The lamp is convenient, portable, 

 cheap and does not appear to be at all dangerous. The cost of 

 chimneys, in most of the coal oil lamps, prevents the use of coal 

 oil from being economical. This plan seems to be a good one to 

 obviate the necessity for a chimney. 



Mr. Bull. — What is the cost of the fluids used ? 



Mr, Dibben. — The alcohol is about thirty-five cents per gallon, 

 and the coal oil about fifty cents. It makes no difference in what 

 proportion they are put into the lamp. The relative proportion 

 consumed will depend upon the manner of trimming. It has been 



