In describing the different floors on which the processes of mashing, boiling and cooling are carried on, we noticed the presence of many large wooden vats full of water. The water in these vats, used principally for mashing and boiling, receives a preliminary heating by means of exhaust-steam, which proceeds from the brewery engines and would be wasted, unless utilized in the manner indicated. An apparatus, specially designed for this purpose, conducts the exhaust-steam into coils fixed in the vats; in this manner the temperature of the water is raised and less heat is required to bring it to the boiling-point. Ordinarily, these vats are entirely covered with thickly padded canvas, to the end that the heat may be more effectually retained. When we consider that the annual consumption of fuel in this brewery amounts to six thousand tons of coal, we can readily understand that a waste of heat, in whatever form, must, in the long run, result in a very considerable pecuniary loss. In its downward course, from floor to floor, the water used for the purposes before mentioned, flows through pipes which empty into the tubs and boilers, and are supplied, at suitable points, with instruments for gauging quantities and determining temperature. By means of powerful steam-pumps, the water is pumped from the Croton main into the vats, where it is heated as described. The vats on the floor next to the ground-floor furnish warm water for cleaning the kegs. Thus, the water, too, passes through a series of connected pipes, vats, tubes and tuns, up and down the entire height of the building, serving a different purpose at every stage and forming another circle within a circle. [Sidenote: REFRIGERATION]