placed in housings with glass sides so that the action of the water on striking the buckets can be observed.
Some experiments have already been made in the laboratory on the flow of air, the results of which have been communicated by Professor Peabody to the American Society of Mechanical Engineers. It is now intended to continue the study of the flow of air and its use as a motive power in great detail, just as the flow of water is studied, and an air compressor of 100 horse-power, which will produce a pressure of twenty-five hundred pounds, is now being installed.
The laboratory for testing the strength of materials was established in 1881 by Prof. G. Lanza, and has since been extensively developed under his direction, until it is now one of the most complete in the world. It is perhaps not too much to say that the experiments made in this laboratory have in some respects revolutionized the ideas of engineers. Previous to its establishment, the only tests of timber that had been made were upon small selected specimens one or two inches square and a few feet long. The results of these tests had been used for years by architects and engineers, and they were given in all the engineering handbooks. In the Institute laboratory there were conducted the first systematic and extended tests of beams of commercial size. The results soon showed that the strength of such timber was a