are kept well braced with timbers on the inside during sinking, so as to avoid all possibility of collapse.

Fourth. See that proper guides are provided for all caissons and cylinders, so that they can be kept in exact horizontal position during the entire sinking.

Fifth. See that the tops of all piers are properly finished off to receive the superstructure, taking care that all bearings are made perfectly smooth and to exact level.

(F) CAISSONS.

First. In building timber caissons, see that the plans are followed exactly, and that the full quantum of timber bolts is used; also, that short timbers are not put in where long ones are called for. See that all timbers are properly framed.

Second. In sinking caissons, see that they are never allowed to deviate materially from correct position, and that all errors of position are corrected as soon as possible after they are discovered.

Third. In filling working-chambers of caissons, see that the concrete is packed tightly against the roof, and that no voids whatsoever are left therein.

(G) CEMENT AND CONCRETE.

First. Test all the cement, according to the special instructions therefor, so long before it is needed for use that the Contractor shall not be delayed by such testing.

Second. See that all cement is housed so as to be protected effectively from the weather, and that no dampened or otherwise injured cement is allowed to be used on the work.

Third. Inspect as soon as delivered, and if possible before it is dumped on the ground, all sand and broken stone, so as to make sure that they comply in every particular with the specifications; and insist always upon all of these materials that are rejected being removed immediately from the vicinity of the bridge site.

Fourth. See that strong and proper forms for concrete are used in the construction of all pedestals, and that all visible