FIRE-PROOF BUILDING CONSTRUCTION. 621 



on the second floor, with a consumption of about three hundred and 

 twenty-five pounds of anthracite coal per day in the furnace. 



The temperature produced by this system of heating is free from 

 the objectionable variations so common with other modes of heating. 

 The walls and floor form such large heating surfaces that the tem- 

 perature is uniform in all portions of the rooms, while the air is not 

 vitiated by escaping gases or heated dust, as is universally the case 

 where furnaces or steam-pipes are used for heating. 



It is not asserted that its economic results per pound of coal are 

 greater than those claimed for the steam or hot-water systems, but, if 

 the latter were required to make as liberal provision for the renewal 

 of fresh air in the interest of an equally good ventilation, the percent- 

 age of useful results per pound of coal from steam or hot water would 

 average no higher than by this method. 



The rain-water falling upon the roof passes through two six-inch 

 iron pipes, which are set in the walls, extend across the cellar, and 

 connect with a beton tank in the rear tower, holding five thousand 

 gallons, whose water-level is thirty inches below the level of the roof. 

 This inverted siphon also forms a distributing system to the various 

 points of consumption in the house, through short branch pipes con- 

 nected with these mains. 



There are also two other tanks made of beton, and holding three 

 thousand gallons, situated under the main tank : one of these sustains 

 a head of over twenty feet of water, and has never given any indica- 

 tions of leakage. 



In regard to the important factor of cost involved in this system 

 of beton construction, its average for beams, floors, and roofs, includ- 

 ing the supporting platforms for laying them down, was a fraction 

 over sixty cents per square foot. This cost also includes the re-en- 

 forcing iron beams and rods. The cost of the heavy wall-work, not 

 including cornices, was about twenty-four cents per cubic foot, which 

 includes the cost of plank molds, required for building up the walls. 

 The advantages that contributed most to these economical results were 

 cheap material and cheap labor. 



The bulk of the material required for the work abounds in inex- 

 haustible quantities, and is always obtainable at moderate cost. The 

 skill needed consists in a simple knowledge of the right proportions of 

 material, and of its proper manipulation, which can be obtained in a 

 half-day's practice. The most inexperienced laborers can do all the 

 work of the most elaborate beton construction, excepting only the 

 surface-finishing, and this, with all the other work, can be superin- 

 tended by one competent, experienced builder. 



Along with the foregoing data, it may be well to include an ac- 

 count of some experiments that were made to test the heat-enduring 

 qualities of beton. A number of large test-bricks were made of 

 the same proportion of materials used in the construction of the walls, 



