Thomas O'Conor Sloane

“ The books are very prolific of instances of expansion by heat, and always speak of the expansion of rails. They do not, however, allude to the geometrical element of danger; they concern themselves only with the physical one. ”

“ The expansion of metals under the influence of heat is very slight. A mile of iron rails, for an elevation of temperature of 100° Fahr., only expands two feet eight and one half inches. This is so little as to be readily taken up by the one hundred and seventy-six joints that exist in that length of rails. If the rails were laid in very cold weather, in solid contact with each other, then, on a warm, sunny day, a consider-able disalignment could be produced. ”

“ As if to render it more susceptible to the rays of the sun, it was painted of dark color. On cold or cloudy days it lay in its normal position. On sunny days, the writer has frequently seen it bowed outward nearly or quite a foot out of line. ”