largest bridges in the United States has piers built with such insufficient batter that it is evident at a glance, to even at untrained eye, that something is wrong. By the way, one of these piers is cracked from top to bottom, owing to false economy in the design, but not because of its failure to figure properly for the curve of pressure.

An inherent sense of fitness in the mind of the designer will generally tell him, when he looks at a scale-drawing of the superstructure and piers of a bridge, whether the latter are properly proportioned. In the case of the Red Rock cantilever bridge over the Colorado River the piers were first laid out fourteen feet wide under coping, with a batter of half an inch to the foot, and the drawings were submitted to the author for his criticism. He immediately pronounced the piers to be proportioned incorrectly, simply because of their appearance. Their proportioning was then turned over to him, and be found by trial that a batter of one and a quarter inches to the foot was necessary. This batter gave a satisfactory appearance to the entire layout.

In nearly every case the length of the piers up and down stream, determined by the minimum size under coping and the proper side-batter for thrust, will provide sufficient strength and stability to resist both current and wind pressure. A thorough investigation of resistance to overturning of piers down-stream is given in Baker's "Treatise on Masonry Construction." In it he proves that any pier which is large enough under coping, and which has ordinary batter, will resist properly the overturning tendency of the worst possible combination of loads from wind, current, and floating ice. Nevertheless, in long-span, single-track bridges with very high piers, crossing swift streams that carry thick ice, and where the structure is exposed to high winds, it is advisable, as a matter of precaution, to test the piers for down-stream overturning according to Prof. Baker's method. Should the length of pier parallel to the stream be found insufficient, the neatest way to obtain the requisite stability is to put in a cocked-hat just above the elevation of extreme high water.

Where a masonry pier rests on bed-rock, the latter should