Presidential Address. Formation of the Principal Engineering Institutions Continued

The British Standard Specification for Portland cement was first issued in 1904 by the Engineering Standards Committee (now the British Engineering Standards Association, incorporated in 1918), a body, as its name implies, entrusted with the framing of engineering standards of all kinds, and supported by all the chief Engineering Institutions of this country. This specification was drawn up by a representative committee, 25 in number, consisting of engineers, contractors and cement manufacturers, etc., under the chairmanship of the late Sir William Mathews, the well-known dock and harbour engineer. D.B. Butler

Let C = the number of parts by weight of Dry Portland Cement. S = the number of parts by weight of dry sand. C = the percentage of water by weight required by the Portland cement. S = the percentage of water by weight required to damp the sand. W = the percentage of water by weight required by the combined weights of Portland cement and sand.

The subject of this paper is the strength of rectangular slabs, but it is limited to such slabs as have an appreciable thickness coinpared with the span, and more particularly it is limited to slabs of reinforced concrete only. A. Ingerslev