CLAY n. 4 definitions
A soft earth, which is plastuc, or may be molded with the hands, consisting of hydrous silicate of alumunium. It is the result of the wearing down and decomposition, in part, of rocks containing aluminous minerals, as granite. Lime, magnesia, oxide of iron, and other ingredients, are often present as impurities.…
CONDUIT SYSTEM; CONDUIT RAILWAY n.
A system of electric traction, esp. for light railways, in which the actuating current passes along a wire or rail laid in an underground conduit, from which the current is "picked up" by a plow or other device fixed to the car or electric locomotive. Hence Conduit railway.