In the old days of cut-stone-masonry piers, the method of proportioning the shafts was to make them as small as possible on top, keeping the pedestals of the spans just within the periphery limits of the first sub-coping course, putting on a batter of half an inch to the foot, and carrying this down as low as the governing conditions would permit, thus ignoring entirely the effect of thrust from trains or wind. For the small structures of those times, with their short spans, this arrangement generally answered the purpose well enough, because the maximum theoretical thrusts assumed in modern bridge practice seldom, if ever, came upon the structures; but occasionally there would arise a case for which this rule-of-thumb method of pier-shaft proportioning would not suffice.

The author recalls an experience of the late eighties when at Albuquerque, New Mexico, he was making the preliminary calculations for the Red Rock cantilever bridge over the Colorado River. The Chief Engineer of the railroad company had undertaken the designing of the piers, and after learning the area required for the main pedestals, he proportioned the coping, then laid out the rest of the shaft with a batter of one-half inch to the foot, and submitted the design to the author for comment. A glance brought the instant conclusion that something was wrong, and upon this being stated the job of pier-designing was turned over to him, whereupon he proceeded to figure the overturning effect on the pier by combined traction and wind loads, with the result that a batter of one and a quarter inches to the foot was found necessary; and this batter gave the layout a decidedly-pleasing appearance.

The day of cut-stone-masonry piers is past—or, at any rate, ought to be; for compared with concrete piers they are always uneconomical. Sometimes, as a defence against the grinding effect of ice, or the disintegrating effects of sea-water between high-water and low-water levels, it is necessary to protect the concrete thus exposed with a facing of granite or other hard rock; and occasionally someone desires to adhere to cut-stone work for the sake of retaining the old-fashioned appearance which it gives to structures; but no engineer who is a student of true economy in design and construction will continue to use coursed masonry in his bridge piers.

There is an economic problem in concrete-pier designing which comes up occasionally whether it is better to reinforce for bending due to traction and wind loads or to omit the rods and use more concrete. There is no

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