Experiences in the Physical and Chemical Examination of Concrete

It would seem plain that if existing conditions continue the structural engineer is in for a good time. The number of schemes under contemplation and in connection with which his services will inevitably be requisitioned, is legion, and they apply with magnificent impartiality to our own country, to the Continent, to South America, and to our own Overseas Dominions. Their realisation will involve the expenditure of fabulous sums of money, the source of which might be the subject of painful contemplation, but for the consoling reflexion that it cannot possibly all come out of the pockets of structural engineers themselves, whereas quite a pleasing proportion of it may reasonably be expected to gravitate in that direction. As structural engineers are but human they will respond to the very human desire to make hay while the sun shines-the colder season of their discontent having already been unduly prolonged. In any case a huge sum of money is being earmarked for purposes good, bad, and indifferent, and while in the long run no section of the community can permanently benefit at the expense of another, and the man in the street-that patient milch cow (if the Hibernism be permitted)-may show signs of fatigue stress at the expenditure contemplated, the structural engineer will want his place in the sun, for as long as it shines.

The inherent and peculiar advantages of the tube as a structural element have many times received consideration in print, and, in aeronautical and automobile construction, in the steel furniture industry and in certain other specialised fields, these advantages have already been turned to practical account. The special benefit attaching to the tubular section lies, of course, in a moment of inertia which is of equal magnitude in all directions, enabling the maximum resistance to buckling to be achieved with the lowest possible area of crosssection and hence the minimum weight. Hitherto, it has rarely been found possible, however, to apply the tubular principle to structural steelwork, for rivetting and bolting are highly unsuitable for the jointing of tubes.

Deaerated concrete is an invention, protected by patent, for mixing concrete in a vacuum, with the object of improving the quality as regards both strength and density.