The Forth Bridge— Shine American Comparisons.

Ashburton Guardian, Volume I, Issue 21, 13 November 1879, Page 3

The Forth Bridge— Shine American Comparisons.

(From the Brooklyn Eoglf.)

The immense height of the towers for the support of the Forth bridge has created some surprise, and no wonder when it is taken into account that when thay are completed they will be the highest buildings of any kind in this world. Science, will, therefore, .wait with some anxiety their completion. The height of the towers on the Inch Garvie, midway between South and North Queensferry, will be 560 feet to support.a bridge * 150 feet above high water mark, but the reason of this great altitude is that in the generality of suspension bridges the towers are built on the land on either side of the span, and were this the case in the Forth bridge towers of 150 feet less in height, or 430 feet, would be sufficient; but this is impossible from the great length of the bridge. It seems that by natural laws there id a limit to everything on this earth— that ia, that man can go a certain length and no further, as, for instance, in telescopes nothing larger than Lord Ross’s having been perfected in many years. In reference to buildings a correspondent the other day quoted St. Rollox stalk 430 feet high. St. Paul’s Cathedral is about 460 feet to top of the dome, St. Peter’s at Rome 480 feet, the Pyramids of Egypt, at least the great pyramid is 180 feet at present in its imperfect state, but by calculation would reach 500 feet in height when finished. When, it is remembered that this structure only reaches this height with a base of about twenty-six acres, it will be a'very difficult matter to raise the, j?prth bridge towers to 500 feet with a sirrtall 'base. These towers are to be forihed of solid masonry to a certain height," and. then by groups of iron pillars girded together in layers upward ; The Niagara suspension bridge; has one large span of 821 feet ; the railway trade above the , water is 245 feet, or 95 feet higher than the Forth bridge ; the towers are only 60,feet high, bbing built on either side of the shore. : The Alleghany bridge has two large spans Of 344;feet, each, and the towers are 45 feet highi, The Covington and Cincinnati bridge has a span of 1,057 feet; its height above low 1 water is 103 feet, and the towers 230 feet high. The bridge seems to give the best proportion to the Forth bridge which is 1,680 feet for two spans, 150 feet high, and tioned are finished and in working order ; and we may mention also the East river bridge, connecting New York to Brooklyn. The towers of this bridge are also built upon the laud and are 378 feet high. The single span is 1,595 feet long, or only 85 feet less than the Forth bridge, while the total length is 5,989 feet. There is, therefore, no doubt that the Forth bridge, when completed, will be an engineering triumph.