Will he know anything of commerce, railroads, telegraphs, printing, and the great number of clerk labors in the larger towns? Will he have learned a single thing which will assist him in his work of life? Will not every boy thus taken out of the shop and placed at the compulsory schooling find after he has mastered all it has to give him that he yet knows nothing; that he must then commence where he was and serve his apprenticeship; that instead of compulsory education his past years have been wasted in obtaining but a compulsory ignorance? * * * * * =Business and Personal.= _The Charge for Insertion under this head is One Dollar a line for each insertion; about eight words to a line. Advertisements must be received at publication office as early as Thursday morning to appear in next issue._ Lubricene.--A Lubricating Material in the form of a Grease. One pound equal to two gallons of sperm oil. R. J. Chard, New York. Assays of Ores, Analyses of Minerals, Waters, Commercial Articles, etc. Technical formulæ and processes. Laboratory, 33 Park Row, N. Y. Fuller & Stillman. Manufacturers of Improved Goods who desire to build up a lucrative foreign trade, will do well to insert a well displayed advertisement in the SCIENTIFIC AMERICAN Export Edition. This paper has a very large foreign circulation. Cutters, shaped entirely by machinery, for cutting teeth of Gear Wheels. Pratt & Whitney Co., Manufacturers, Hartford, Conn. 18 ft. Steam Yacht, $250. Geo. F. Shedd, Waltham, Mass. Electrical instruments of all kinds. One Electric Bell, Battery, Push Button, and 50 feet Wire for $4.00. Send for catalogue. H. Thau, 128 Fulton St., N. Y. Wheels and Pinions, heavy and light, remarkably strong and durable. Especially suited for sugar mills and similar work. Pittsburgh Steel Casting Company, Pittsburgh, Pa. Boilers ready for shipment, new and 2d hand. For a good boiler, send to Hilles & Jones, Wilmington, Del. Best Steam Pipe & Boiler Covering. P. Carey, Dayton, O. Foot Lathes, Fret Saws, 6c., 90 pp. E. Brown, Lowell, Ms. Sperm Oil, Pure. Wm. F. Nye, New Bedford, Mass. Power & Foot Presses, Ferracute Co., Bridgeton, N. J. Kreider, Campbell & Co., 1030 Germantown Ave., Phila., Pa., contractors for mills for all kinds of grinding. Punching Presses, Drop Hammers, and Dies for working Metals, etc. The Stiles & Parker Press Co., Middletown, Conn. All kinds of Saws will cut Smooth and True by filing them with our New Machine, price $2.50. Illustrated Circular free. E. Roth & Bro., New Oxford, Pa. "The Best Mill in the World," for White Lead, Dry, Paste, or Mixed Paint, Printing Ink, Chocolate, Paris White, Shoe Blacking, etc., Flour, Meal, Feed, Drugs, Cork, etc. Charles Boss, Jr., Williamsburgh, N.Y.