This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1901 Excerpt: ...of cold air by inward leakage around the window-frames. In New York the windows of office-buildings are fairly well fitted, and are usually weather-stripped after the first season; but as the first season forms the basis of test, allow ance should be made for the introduction of cold air through leakage. For very large or unusually lofty rooms with disproportionately small exposed surface, some allowance has to be made for dissipation of heat from the rear or from the upper part of the room, and in such a case the ratio of the total cubic contents to the total heating surface, expressed in corresponding units, should not be less than 80 to 1. A good ratio is found by dealing with 20 feet of the exposed end of the room by the formulas, and a relation of 1 square foot of surface to each 100 cubic feet of the rear part of the room. The methods of supplying steam to, and affording egress for condensed steam from, sectional radiators are known as the " onepipe," "two-pipe" and "three-pipe" systems. In the first, a single pipe supplies steam and is made large enough to permit the condensed water to return by gravitation against the flow of the steam. In the second, a separate supply-pipe and a separate returnpipe are provided. In the third, an additional pipe of small size is provided for the escape of air and gases. The economy of the use of waste steam for heating is manifest, and it is interesting to apply its effect to the Rankine cycle. Referring to the Report1 of the Committee of the Institution on the Thermal Efficiency of Steam Engines, and to the accompanying diagram of the cycle of efficiency, it will be seen that, where the waste heat is thus usefully employed,. the whole of the thermal units emitted by the engine into the...