A vessel in which aqueous or spirituous vapours are reduced to a liquid form, either by injection of a quantity of cold water, as in the condenser of a steam-engine; or when this is inadmissible, as in the case of alcoholic vapour, by placing the condenser in another vessel, through which is maintained a constant current of water, the condenser being so constructed as to expose the steam or vapour in thin strata over an extended surface to the action of the cooling medium. The condensers employed by distillers are usually composed of a long tube of pure tin, or of copper tinned, formed into a series of concentric coils over one another, and from its shape denominated a worm; this is placed in a large vat, which is called the worm-tub. But when the distillation is carried on upon a large scale, the worm is not of a cylindric section, as it is not the form which is best adapted for the purpose of condensation; for on account of the large diameter of the tube, which then becomes necessary, that portion of vapour which occupies the centre of the tube is not brought into sufficiently intimate contact with the cooling surfaces, and therefore either escapes condensation, or requires a much larger quantity of water than would be otherwise necessary.

Various arrangements have, in consequence, been devised for presenting the vapour in extremely thin strata, so as to obtain a ready condensation with the least quantity of water. One invented by Mr. Wheeler, of High Wycomb, appears to us very judiciously arranged for this purpose; it is denominated by the inventor the Archimedes' Condenser and is represented in the accompanying engraving, a is the pipe leading from the neck of the still, through which the vapours enter into the flat chambers b b (represented black). These chambers, owing to the sectional view, appear to be disconnected, but they are wound spirally round a central tube, and terminate at the cock c, where the condensed products pass off; d is a pipe leading from a reservoir of cold water to the bottom of the central tube, where it passes through holes represented at e e underneath the vapour chambers, and can only ascend in the vessel by passing successively through every coil, as each turn of the spiral is connected by the edge of one of its plates to the side of the containing vessel. The water thus heated in its progress flows out at the aperture f into a trough or pipe.

By this arrangement it will be noticed that the hot vapour or fluid is constantly descending spirally an inclined plane, while the cold fluid is constantly ascending, almost in contact with the other, as they are only separated by a very thin plate, formed of the best conducting substance (copper). It will likewise be evident that two fluids, one cold and the other hot, may thus be made to exchange their temperatures. Thus, if cold water at 50° Fahr, be admitted at the bottom of the vessel, it will, when it arrives at the top, be nearly of the same temperature as the vapour or liquid (say 200°), which entered at the top, by having gradually abstracted the heat from the vapour or hot liquid in its progress. This being understood, it follows that the latter, having gradually parted with its heat in its descent, will become of the same, or nearly the same temperature at the termination of its course as the water, namely 50°, provided the liquids be admitted in their proper volume, which is easily regulated by the cocks.