The classification is natural, as, for instance, objects pertaining to various animals, birds, and fishes, such as skins, hides, hair, fur, feathers, wool, quills, down, bristles, teeth, bones, hoofs, horns, tusks, shells; natural products such as woods, barks, roots, leaves, nuts, seeds, gums, grains, flowers, meals, bran; also minerals in great assortment; mineral and vegetable oils, clay, mica, ozokerite, etc. In the line of textiles, cotton and silk threads in great variety, with woven goods of all kinds, from cheese-cloth to silk plush. As for paper, there is everything in white and color, from thinnest tissue up to the heaviest asbestos, even a few newspapers being always on hand. Twines of all sizes, inks, wax, cork, tar, rosin, pitch, asphalt, plumbago, glass in sheets and tubes, and a host of miscellaneous articles are revealed on looking around the shelves, as well as an interminable collection of chemicals including acids, alkalies, salts, reagents, every conceivable essential oil, and all the thinkable extracts. It may be remarked that this collection includes the eighteen hundred or more fluorescent salts made by Edison during his experiments for the best material for a fluoroscope in the early X-ray period. All known metals in form of sheet, rod, and tube, and of great variety in thickness, are here found also, together with a most complete assortment of tools and accessories for machine-shop and laboratory work. The list above given is not by any means complete. In detail it would stretch out to a rather large catalogue. It is not by any means an idle collection, for a stock clerk is kept busy all the day answering demands upon him. Beyond the stock-room is a good-sized machine-shop, well equipped, in which the heavier class of models and mechanical devices are made. Attached to these are the engine-room and boiler-room. Above, on the second floor, is another machine-shop, in which is carried on work of greater precision and fineness in the construction of tools and experimental models. There are many experimental rooms on the second and third floors of the laboratory building. In these the various experimenters are at work carrying out the ideas of Mr. Edison on the great variety of subjects to which he is constantly devoting his attention. One cannot go far in the upper floors without being aware that efforts are being made to improve the phonograph, for the sounds of vocal and instrumental music can be heard from all sides. On the third floor the visitor may see a number of glass-fronted cabinets containing a multitude of experimental incandescent lamps, and an immense variety of models of phonographs, motors, telegraph and telephone apparatus, and a host of other inventions, upon which Mr. Edison's energies have at one time or other been bent. Here are also many boxes of historical instruments and models. In fact, this hallway, with its variety of contents, may well be considered a scientific attic.