Supplement to Spons Dictionary of Engineering, Civil, Mechanical, Military, and Naval Volume 3 (Paperback)

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1881 edition. Excerpt: ...in below the wheel surface, so that it then ran with merely a smooth tire, but when they were projected it was o rigid spiked wheel. The bite of such a wheel on cobble-stones, between which the spin Is inserted themselves, was equal to cog-gearing, and on macadam the peculiarly shaped spuds inserted themselves into the surface of the road, and produced a similar effect, but to a smaller extent. This plan answered well for some roads, but it was evidently not suited for general use on account of the damage done to the highways, and the continued breakages in the mechanism of the wheels, cansed by the unequal strains on the connecting rods of the spuds. B. W. Themson, of Edinburgh, in 1867, constructed a wheel consisting of a very light wroughtiron drum, 4 ft. diameter, by 15 in. wide, with flanges, 1 in. high, on either side. Outside this drum was stretched a flat indiarubber band, or tire, 12 in. wide by 5 in. thick. The wheel ran with the indiarubber in contact with the ground. It was found to slip on damp roads and greasy mud. To obviate this, Themson covered the indiarubber tire with flat steel plates, or shees. These were 1901. turned over at the ends and joined together by ordinary flat links, as in the upper parts of Figs. 1903,1904, some of which were of different lengths, in order to compensate for the elongation of the chain by wear. This species of armour was very troublesome, owing to the continuous breakage of the link pins, and the difficulty of keeping the tire in its place unless the shees were very tight. Another system of protecting the indiarubber tire was invented by Themson, and improved by Burrell, it is seen in the lower parts of Figs. 1903, 1904. In this case the steel plates touch each other outside the tire, and...