THE LIME

Too Long; Didn't Read

To make mortar with which masonry is held in place it is customary to use lime. In a sort of trough lined with sand are placed lumps of stone having a calcined appearance, and on these stones water is poured. In a few moments the pile becomes heated to high temperature, cracks and splits and finally crumbles into dust, at the same time absorbing the water, which disappears little by little as it is taken up by the solid matter or vaporized by the heat. More water is added to reduce it all to paste, which is finally mixed with sand. The product of the mixture is mortar. Such is the process often witnessed by Emile and Jules, who are always surprised, that stone, by having water poured on to it, should become hot and turn the water into jets of steam. “Lime,” Uncle Paul explained to them, “is obtained from a widely diffused stone called limestone or, in more learned language, carbonate of lime. The process is of the simplest sort. It consists of heating the stone in kilns built in the open air in the vicinity of both limestone and fuel, so as to avoid the expense of transportation in the manufacture of a product that it is desirable to furnish at a low price.[48]