Alexander A. Lawes, civil engineer, of Sydney, Australia, suggests a plan of mechanical flight on beating wings as presenting advantages that transcend all other schemes. He believes that the amount of power required to operate wings and the difficulty in applying it are exaggerated beyond all measure. The wings or sustainers of the bird in flight, he urges, are held in the outstretched position without any exertion on its part; and many birds, like the albatross, sustain themselves for days at a stretch. "This constitutes its aërial support, and is analogous to the support derived by other animals from land and water." The sole work done by the bird is propulsion and elevation by the beating action of the wings. Mr. Adams's machine, which he does not say he has tried, is built in conformity to this principle, and its sails are modeled as nearly as possible in form and as to action with those of the bird. The aid of an air cylinder is further called in, through which a pressure is exerted balancing the wings. The wings are moved by treadles, and the author's picture of the aëronaut looks like a man riding an aërial bicycle. Carborundum, a substance highly extolled by its manufacturers as an abrasive, is composed of carbon and silicon in atomic proportions--thirty parts by weight of carbon and seventy of silicon. It is represented as being next to the diamond in hardness and as cutting emery and corundum with ease, but as not as tough as the diamond. It is a little more than one and a fifth times the weight of sand, is infusible at the highest attainable heat, but is decomposed in the electric arc, and is insoluble in any of the ordinary solvents, water, oils, and acids, even hydrofluoric acid having no effect upon it. Pure carborundum is white. In the commercial manufacture the crystals are produced in many colors and shades, partly as the result of impurities and partly by surface oxidation. The prevailing colors are green, black, and blue. The color has no effect upon the hardness. Crude carborundum, as taken from the furnace, usually consists of large masses or aggregations of crystals, which are frequently very beautifully colored and of adamantine luster.