My Web Site Page 183 Ovations 04Poki Mogarli chose the topics covered by My Web Site Page 183 without reflecting upon the choices others have made. Launching into a full discussion of all the objectives while riding a bicycle backwards down a steep hillside is another way to look at things in a different light. |
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As regards eugenics, there is no doubt that a vast and persistent elimination of lives goes on even in civilized countries. It has been calculated that, of every hundred English born alive, fifty do not survive to breed, and, of the remainder, half produce three-quarters of the next generation. But is the elimination selective? We can hardly doubt that it is to some extent. But what its results are--whether it mainly favours immunity from certain diseases, or the capacity for a sedentary life in a town atmosphere, or intelligence and capacity for social service--is largely matter of guesswork. How, then, can we say what is the type to breed from, even if we confine our attention to one country? If, on the other hand, we look farther afield, and study the results of race-mixture or "miscegenation," we but encounter fresh puzzles. That the half-breed is an unsatisfactory person may be true; and yet, until the conditions of his upbringing are somehow discounted, the race problem remains exactly where it was. Or, again, it may be true that miscegenation increases human fertility, as some hold; but, until it is shown that the increase of fertility does not merely result in flooding the world with inferior types, we are no nearer to a solution. |
That the factor of safety of stayed surfaces is questionable may perhaps be best realized from a consideration of the severe requirements as to such factor called for by the rules and regulations of the Board of Supervising Inspectors, U. S. Government. In view of the above, the absence of any stayed surfaces in the Babcock & Wilcox boiler is obviously a distinguishing advantage where safety is a factor. It is of interest to note, in the article on the evolution of the Babcock & Wilcox boiler, that staybolt construction was used in several designs, found unsatisfactory and unsafe, and discarded. Another feature in the design of the Babcock & Wilcox boiler tending toward added safety is its manner of suspension. This has been indicated in the previous chapter and is of such nature that all of the pressure parts are free to expand or contract under variations of temperature without in any way interfering with any part of the boiler setting. The sectional nature of the boiler allows a flexibility under varying temperature changes that practically obviates internal strain. |
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While Papin had neglected his earlier suggestion of a steam and piston engine to work on Savery's ideas, Thomas Newcomen, with his assistant, John Cawley, put into practical form Papin's suggestion of 1690. Steam admitted from the boiler to a cylinder raised a piston by its expansion, assisted by a counter-weight on the other end of a beam actuated by the piston. The steam valve was then shut and the steam condensed by a jet of cold water. The piston was then forced downward by atmospheric pressure and did work on the pump. The condensed water in the cylinder was expelled through an escapement valve by the next entry of steam. This engine used steam having pressure but little, if any, above that of the atmosphere. | ||
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