Supplement to Spons' dictionary of engineering Volume 3 ; civil, mechanical, military, and naval

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. 1881 Excerpt: ...and it was shown that it could run with facility over soft land upou which a horse could not move a light cart. The great surface of the shoes in contact with the ground, enabled it to haul great weights over bogs, and to perform many other feats, which quickly brought the engine into notice. Indeed, its pulling power was so great, that a single driving wheel gave more than sufficient bito for all ordinary hauling work; and, consequently, several engines were constructed with only one side of the machine fitted with the travelling trams, a'good plan to save expense, but one calculated to destroy the general efficiency of a locomotive, as its facility of steerage is thereby much impaired. Boydell's wheel clearly proved that a large surface in contact with the ground tended to an increase of efliciency, but at a great outlay of wear and tear. There was no elastic medinm to deaden the concussion, and the whole apparatus went clattering along, an extraordinary combination of inharmonious mechanism. However, the arrangement was continued for many years. Some short time after Boydell had brought his engines into public use, and when the great advantages of increased adhesion had become clearly known, Bray, of Kent, brought out his spudded wheel, Figs. 1901, 1902, by means of which it was hoped to gain sufficient adhesion, without complexity and liability to breakage. Bray's wheel had a rigid tire fitted with short, strong spikes to dig into the road surface as it rolled along. These spuds could, by an eccentric, be drawn in below the wheel surface, so that it then ran with merely a smooth tire, but when they were projected it was a rigid spiked wheel. The bite of such a wheel on cobble-stones, between which the spuds inserted themselves, was equal to cog-gearing,...