The sample taken for specific gravity and fineness is dried in the oven at 100° cent. in order to drive off moisture. Two samples are then carefully weighed out, 50 grammes for fineness and 64 grammes for specific gravity, and the determinations are made. As soon as anything unsatisfactory develops, a re-test is made. If, however, the cement satisfies all requirements, a report sheet containing all the data for a bin, is made out, and the cement is ready for shipment. From every fifth bin, special neat and mortar briquettes are made, which are intended for tests at ages up to ten years. _Salt-Water Laboratory._--The laboratory at Atlantic City, for conducting investigations into the effects of salt water on concrete and reinforced concrete, is situated so that water more than 25 ft. deep is available for immersion tests of the setting and deterioration of such materials. Through the courtesy of the municipality of Atlantic City, Young’s cottage, on old Young’s Pier, has been turned over, at a nominal rental, to the Geological Survey for the conduct of these tests. The laboratory building is about 700 ft. from the boardwalk, and occupies a space about 100 by 45 ft. It is one story high, of frame-cottage construction, and stands on wooden piles at one side of the pier proper and about 20 ft. above the water, which is about 19 ft. deep at this point. Fresh running water, gas, electric light, and electric power are supplied to the building (Fig. 6). In this laboratory investigations will be made of the cause of the failure and disintegration of cement and concrete subjected to the action of sea water. Tests are conducted so as to approach, as nearly as possible, the actual conditions found in concrete construction along the sea coast. All sea-water tests are made in the ocean, some will probably be paralleled by ocean-water laboratory tests and all by fresh-water comparative tests. Cements, in the form of pats, briquettes, cubes, cylinders, and in a loose ground state, and also mortars and concretes in cube, cylinder, and slab form, are subjected to sea water. The general plan for the investigations is as follows: 1.--Determination of the failing elements and the nature of the failure; 2.--Determination of the value of the theories advanced at the present time; and, 3.--Determination of a method of eliminating or chemically recombining the injurious elements. Preliminary tests are in progress, including a study of the effect of salt water on mortars and concretes of various mixtures and ages. The proportions of these mixtures and the methods of mixing will be varied from time to time, as suggested by the progress of the tests.