SIR,-Mr. Wollaston, in his letter in the current number of The Structural Engineer, has apparently forgotten the subject of the discussion. His remarks on the distortion of the box are not relative to the point at issue, and I do not propose to follow his lead by entering into a discussion on the distribution of internal stresses in foundation blocks.
THEORETICAL DISCUSSION. In 1833 Clapeyron stated his law of general work: “For any frame of constant temperature and acted on by loads which are gradually applied, the actual work produced during deformation is independent of the manner in which these loads are created and is always half as great as ths work otherwise produced by forces retaining their full end values during the entire act of deformation.” H.W. Coultas
In contrast to driving bearing piles for which the direct resistance below the point often becomes greater than the frictional value that the sides can afford, sheet steel piles encounter the greater proportion of their resistance through friction between the ground and their side surface which is very considerable compared with the sectional area of the solid steel pile which can, however, transmit a very high driving force without becoming deformed. A. Hiley