At present the department of physics and electrical engineering, under the head of Prof. Charles R. Cross, has an active teaching force of one professor, four assistant professors, six instructors and three assistants, a total of fourteen. In addition to these, there are twelve lecturers on special topics, including many men eminent in their profession. The Rogers laboratories occupy sixteen rooms in the Walker Building, including two lecture-rooms and ten laboratories. As in the case of the chemical department, these laboratories are highly specialized. There is a laboratory for general physics, one for electrical measurements, two rooms devoted to a laboratory for electrical engineering, containing two distinct power plants driven by steam engines of 100 and 150 horse-power, with a large number of dynamo machines, transformers and a great variety of other apparatus arranged for purposes of instruction, the mere enumeration of which would occupy several pages. Moreover, a lighting and power plant in the new building on Trinity Place is available for experiments and instruction. Besides these, there are rooms for photometry, for heat measurements, for acoustics, for optics and for photography. In fact, probably no department of the Institute is more fully equipped than this, the wealth of apparatus being so great that the casual visitor is confused by the network of wires and machinery which surround him. The interdependent and harmonious work of the various departments of the Institute is shown in the development of special lecture and laboratory courses, and is in marked contrast to the policy of departmental isolation sometimes practiced. Thus, in 1889, two new courses of instruction were established by the physical department in response to the demand of the department of mining; namely, the course in heat measurements, including measurements of high temperatures, the determination of the calorific power of fuels, etc., and a course on the applications of electro-metallurgy to chemical analysis, the reduction of ores and similar problems. The equipment of calorimeters, pyrometers, etc., in the heat laboratory is said to be so large as to permit a more complete examination of the efficiency of fuels than has hitherto been possible anywhere. [Illustration: SMELTING FURNACE IN JOHN CUMMINGS LABORATORY OF MINING AND METALLURGY.]