two parts sand, and having thin joints perfectly filled, are better than the average masonry pier, for the reason that the bricks will never disintegrate, while the average stone used for bridge-piers will. The author has not yet had occasion to build any brick piers; but he intends to give them a trial on the first opportunity.

Unprotected concrete piers are satisfactory for Southern rivers, where the effect of frost is not severe, and where there is no ice of any account carried by the stream. The author used this style of pier for the Arkansas River bridge of the Kansas City, Pittsburg, and Gulf Railroad near Redland, Ind. Ter. Several other Southern bridges have piers of this type, and thus far they have proved satisfactory. Their chief recommendation is their cheapness. In order to ensure their being properly built, nothing but the best qualities of cement and sand should be employed, and the mortar for the concrete should be mixed rich, especially near the exterior of the piers. Some engineers give the work a skin-coating of rich mortar; but the author prefers to use finely broken stone and extra-rich mortar for six or eight inches all around, and to not attempt to smooth down the exterior. Of course it is practicable to put on a skin-coat so that it will stay, and so that it will not have a streaky appearance; but to do this requires more care than the average workman is inclined to take.

Steel shells filled with concrete make very satisfactory piers, provided they be not used in salt or brackish water, which would rust them out in a short time. These piers are applicable where good stone for masonry is expensive, and where the piers must be protected from the abrasion of ice or from the excessive cold, which would lend to disintegrate even fairly good concrete. Such piers can be built in the usual form of masonry piers with rounded ends all the way up, or, when they pass much above high water, they may run off into two cylinders with bracing between. Butt-spices are preferable, and the splice-plates below the mud line should be placed on the inside so as to offer as little resistance as possible to sinking.

This style of pier is a favorite one of the author's, for the