also machinery for studying the wear of brake shoes and wheel tires, a subject in regard to which there is room for much investigation. Finally, mention should be made of machinery for investigating the interesting subject of the effect of repetition of stress. [Illustration: FORGE SHOP.] The tests performed in the engineering laboratory cover almost the entire range of mechanical science. Sometimes investigations are carried on through a number of years; for instance, during three successive years experiments were conducted and formed the subject of theses on the proper method of counterbalancing the reciprocating parts of a locomotive. Nor are the tests performed by the Institute students as a regular part of their instruction confined to these laboratories, as is made evident by the fifty-hour test of the West End Street Railway power station and the twenty-four hour test of the pumping engine at Chestnut Hill, both recently carried out. In connection with the engineering laboratories, brief mention may be made of the shops, which form an important adjunct of the laboratories. They consist of a shop for carpentry, wood-turning and pattern-making, equipped with forty carpenters’ benches, thirty-six pattern-makers’ benches and a full equipment of saws, planers, lathes, etc.; a foundry with a cupola furnace for melting iron, thirty-two moulders’ benches, two brass furnaces and a core-oven; a forge shop with thirty-two forges, a power hammer, vises, etc.; a machine shop with about forty lathes, together with drills, planers and all the other necessary apparatus used in machine tool work. The magnitude of the Institute laboratories is shown by the following statements: The total horse-power of steam and other engines is nine hundred and eighty-three; the total capacity of tension, compression and transverse testing machines is over eight hundred thousand pounds, and of torsion testing machines about one hundred and fifty-six thousand inch pounds; the total horse-power of hydraulic motors is sixty-two; and the total capacity of pumps is thirty-two hundred gallons per minute. The engineering laboratories are used by students of all the engineering departments, that is to say, by a large majority of the students in the school. The benefit derived by this actual contact with materials and with machines of commercial size, under proper instruction, is believed to be very great.