378 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



been done rather than indulge in hopes and speculations of what may be 

 done. Bituminous coal has been burned in locomotives on the Illinois Cen- 

 tral railroad, and an analysis of the gases in the fire box showed that the 

 combustion was perfect — there was no carbonic oxyd, nor any hydrocar- 

 bons. The same results have been produced in other places. The problem 

 of making a furnace that will burn bituminous coal without smoke is 

 already solved. 



Mr. Dibben. — One word before we adjourn, in reply to Mr. Tillman's 

 remarks on Siemens' furnace. I conversed last week with a friend who 

 had charge of one of these furnaces, and he says the economy is as high as 

 stated. The temperature of the escaping gases has been measured by a 

 pyrometer, and it is found that while in ordinary furnaces the products of 

 combustion enter the smoke stack at a temperature of 2,600° to 3,000°, by 

 Siemens' regenerators all but 300° of this heat is taken from them and 

 imparted to the air and gas before they are combined in combustion, thus 

 utilizing 2,300° to 2,700° of heat which are now wasted. The coal is first 

 distilled into combustible gases, and then these gases are heated before 

 they are burned, the air to burn them being also heated. The gases pro- 

 duced by this combustion pass through interstices in two masses of brick 

 work, heating them, and giving up their own heat, so that they enter the 

 stack at the low temperature named. When the brick work becomes heated 

 the hot products of combustion are turned through two other masses of 

 brick work, and the air and gas are drawn through the two which have 

 just been heated. It is by this saving of waste heat that the great economy 

 is effected. 



Mr. Tillman. — The double passages for the products of combustion alter- 

 nately are not new. Siemens' masses of brick work will undoubtedly last 

 well, but it takes up room which cannot be spared except in a few cases. 

 It certainly could not be used in locomotives. 



The same subject was adopted for the discussion next week, and the 

 Association adjourned. Ends Stevens, Secretary pro tern 



American Institute Polytechnic Association, ] 

 October 16, 1862. j 



Prof. Joy being absent, on motion of Mr. Fisher, Samuel D. Tillman, 

 Esq., was called to the chair. 



Mr. Fisher read an extract from the London Times relative to the per- 

 formance of steam traction engines in the streets of London, and added 

 some comments upon the feasibility of the kind of locomotion on common 

 roads. 



The sewing machine of Madame Demarest, of New York city, was then 

 exhibited and put into practical operation, which gave very general satis- 

 faction to the spectators. The peculiarity of this machine is that the needle 

 is stationary and the cloth is crimped and run upon it. It is, therefore, 

 apparently only intended to sew the lightest kind of cloth. The machine 

 is sold at the moderate sum of five dollars. 



