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Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1864. Excerpt: ... length, and the greater comparative strength at the breech, required for large guns than for smaller ones, are both consequences of the different action of the powder when used in larger quantities. Some writers (Captain Blakely amongst others) have attempted to show that the greater liability of large guns to burst arises from their being subject to a severe strain for a longer time than short ones. It is argued In an article in the Mechanics'' Magazine of 26th September, 1857, On Improvements in Ordnance, by Captain Blakely, R. A., are the following remarks: Large guns require more strength than small ones, as the powder occupying in each the same proportional space, the small shot moves in, say, aioth of a second, a certain number of inches, the large shot in the same time moving fewer inches; so that at the end of that time, the gas in the small gun would have much more proportional room to expand in, and would therefore press less on the gun than in the larger one. Added to this, the large shot would require more time to get its velocity, and the pressure must remain on the gun so much longer. The views embodied in the above extract agree perfectly with the ordinary theory, but are quite contrary to my experiments. According to those views, a greater pressure is first exerted upon guns of large size after the shot has commenced moving; whereas it has been shown by my experiments that a greater proportionate strain takes place at the first instant of the explosion. In the former case, the breech end, or seat of the explosion--and, indeed, all the relative parts--in large guns, would require to be of the same proportionate strength only as those of smaller calibre. In the latter case, it would have to be of a greater proportionate strength. With re...
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