Journal of the Franklin Institute of the State of Pennsylvania, for the Promotion of the Mechanic Arts, Vol. 44

Download or read book Journal of the Franklin Institute of the State of Pennsylvania, for the Promotion of the Mechanic Arts, Vol. 44 written by John F. Frazer and published by Forgotten Books. This book was released on 2018-02-02 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt: Excerpt from Journal of the Franklin Institute of the State of Pennsylvania, for the Promotion of the Mechanic Arts, Vol. 44: Devoted to Mechanical and Physical Science, Civil Engineering, the Arts and Manufacture This table shows that, of the three systems of draft indicated, according to the hypotheses, and with the same numerical data nearly approximating to the circumstances which may present themselves in practice, that in which the air drawn out is heated on the level Of each story, will cause, for the same expenditure of heat, a rather greater velocity for the basement, about the same for the first story, and a little less for the second story, than that in which the draft is pro duced from below. As to the system in which the furnace is placed above the stories to be ventilated, it will cause, as was to be expected, velocities in all the cases rather less than the other two systems. The system of draft from the level appears therefore to be the most advantageous of the three: its superiority and that Of the draft from below over that of the draft from above is to be entirely attributed to the fact that in the two first systems, the heights Of the discharge chimneys permit more advantage to be taken Of the specific levity given to the air: but it must not be forgotten that, as the walls Of the chimney cool the air which passes through them, the velocity may thus be diminished and the advantage of this arrangement somewhat reduced. However this may be, it appears to me to result from this discussion that the system of draft from the level ought to be preferred to the two other systems; its introduction presents no difficulties Of construe tion, and according to the examination Of the proposals for the offices Of the Northern Railroad, it appears to be both more economical in cost Of construction and of daily expenditure: the great height Of the chimneys must also give great stability to the effects. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.