Mr. James Douglas, president of the Copper Queen Company, New York, thus describes automatic devices in metallurgy: “The gold mill, with its series of automatic operations, is the offspring of Californian ingenuity. In it manual labor is almost entirely replaced by ocular labor, for superintendence and not work is the function of the mill-hands. The ore, dumped into the breakers, falls into large pockets, whence it slides into automatic feeders, which supply the stamps with regulated quantities. The free gold is partly extracted by liquid mercury in the mortars, and by copper plates attached to their sides, and partly on an apron of amalgamated copper plates, over which crushed pulp flows as it issues from the battery screen. Automatic vanners receive the tailings, separate the sulphurets, and discharge the waste. When the power is water, the stream is divided to Pelton wheels, coupled to the separate groups or even pieces of machinery. The absence of intermediate running gear increases not only the sense, but the reality of automaticity, and makes a skilfully arranged and thoroughly equipped Californian mill one of the triumphs of modern mechanical metallurgy.” Directive Paths. An interesting field of ingenuity concerns itself with giving work the right start and a simple path. A tear in a sheet of paper accurately follows the line of a directive crease. Postage stamps, small as they are, we readily detach from one another because perforations give direction to the tearing strain. So the quarryman takes care to cut a V-shaped groove in the rock he is to break, along which groove the break takes its way. A bolt when over-strained will break in the thread, whether this be the smallest section or not, because the thread is a starting point for a parting. A rod of glass is divided with a slight jar, provided that a groove has been filed in its surface. In all this there is shown the importance of avoiding in a casting, or forging, such minute cracks as under severe strain may lead to rupture. The Pianola. Within the past ten years automatic musical instruments have been much improved and are now well established in public favor. Not a few teachers of mark use them in their schools as a means of familiarizing their pupils with the best music. All these instruments afford an opportunity for expression on a performer’s part; the effects producible by a practiced performer are remarkable, and give color to the prediction that automatic music may have a parallel history with that of the photograph, which has at last attained a truth and beauty which bring it to a rivalry with the art of the painter. From the educational series issued by the Æolian Company, New York, a few notes from Schumann’s “Traumerei” are here given, together with these notes as they appear on a music roll for the Pianola. [Illustration: Schumann’s “Traumerei,” first notes.] [Illustration: First notes of the “Traumerei” on a Pianola roll.]