Influence of the Quantity of Mixing Water on the Heating During the Hardening of Aluminious Cements

In recent years structural steelwork and reinforced concrete have progressed upon somewhat parallel lines, and comparatively little has been done in combining the two methods of construction. This is probably due to the fact that the two methods of construction have been regarded as competitors, and the specialists in each of the methods have concentrated upon demonstrating the advantages of the one compared with those of the other. Ewart S. Andrews

AT the present time there are so many varieties of roof coverings on the market from which to choose, that it has become a problem for the discerning architect or engineer to decide definitely upon which class of roof covering to specify for the building he may have under consideration. This is a much more important item in building construction than seems to be generally recognised, and one to be decided early, as the type of covering to be used has an influence, not only on the roof design, but on the whole supporting structure. A new roofing, however efficient and economical in actual use it may be, does not always appeal immediately to the conservative architect or engineer. He probably has had experiences, or is profiting by the experiences of others who have been carried away by the verbosity of the salesman to his ultimate disillusionment. The architect and engineer must be satisfied that the material he proposes to employ on his roof is the most efficient and economical he can procure, that it will be suitable for his purpose, and that, when in use, it will be a lasting credit to himself and satisfactory to his client.

THE following remarks apply to the use of Portland Cement only, and are based on the author's own experience :- The time seems to be past when engineers seriously objected to the use of reinforced concrete in sea-water, although its application has not always been successful, but when this has been the case, serious faults in design or execution account for such results. Herluf Forchhammer