Page:Great Neapolitan Earthquake of 1857.djvu/199

TABLE OF FACTORS FOR COEFFICIENT. The use of the coefficient $$\mathrm{L}$$, in Eq. XXI. et seq., considers the value of $$l$$ (Eq. $$\mathfrak{A}$$) evanescent, so that the prism at the moment of fracture has not risen through an appreciable angle, at the surface of fracture, and from the extremely small extensibility of mortar, stones, &c., this is sufficiently true to nature.

It appears, from the few experiments that have been made, that the resistance of stones, &c., to tension, varies from $$\tfrac{1}{8}$$th to $$\tfrac{1}{10}$$th the resistance of the same material to