nomical methods. Accordingly, there are laboratories for mechanical engineering, hydraulic engineering, mining engineering, electrical engineering, and chemical engineering, in which are installed machinery and apparatus similar to that found in actual practice. Such laboratories have been found essential for the best professional and technical education, and are a distinct feature of well-equipped technical schools and universities in Europe and America. A mechanical engineering laboratory contains machinery for studying different forms of motors and power transmission and for determining their most economical operation. This would include the ascertaining of friction losses, the study of various kinds of lubricants, etc. In order to carry on this work as successfully as possible, machinery of such size as will be found in a small plant is necessary, and the students are taught its actual operation and maintenance. In some schools there may be an independent steam-engineering laboratory, while in others it may be a part of the laboratory of mechanical engineering. Here the students are taught to use steam-engines of different types under varying conditions of service. In the important schools of mines are usually found the various machines used in mining and the preparation and reduction of ore. Locomotive engineering is now taught in the laboratory, and at least two universities in the United States, as well as several manufacturing works, are supplied with testing locomotives in which full friction, draught, and other tests can be made on a large scale. Electrical-engineering laboratories were perhaps the first to be carried on on an extensive scale, as in the laboratory method of instruction machinery of more than model size was early found necessary for the student. In the best electrical-enginering laboratories are to be found motors and dynamos for direct and alternating current-transformers, storage batteries, etc., and the various problems involved in the generation of the electrical power and its transmission are studied under conditions approaching actual practice as nearly as possible. In chemical engineering the growth of large manufacturing establishments has led to a demand for practical chemists, and it is now considered that these can best he trained by having students carry out preparations on a considerable scale by using actual machinery. In the most modern of laboratories for the study of applied chemistry, such processes as dyeing, the manufacture of sugar, the manufacture of sulphuric acid, electrolytic methods of preparing chemical substances, distillation, etc., are all carried on on a practical scale.
In engineering laboratories the practice will vary widely in different institutions and with different instructors, depending on adequacy of equipment and number of students. The machinery and apparatus at the disposal of the students and instructors will often influence the work done, and will cause students desiring to follow a particular branch to select an institution where such facilities are the best. Engineering laboratories usually follow adequate manual training and work in chemical and physical laboratories, and the best results are secured when the work is properly coördinated. They have a distinct bearing on technical education, and have played their part in the industrial development of the United States.
Biological Laboratories. An enormous impulse was given to the purely scientific advancement of biological science by the early foundation of laboratories for research in connection with the chief German universities in the third quarter of the last century. In the United States, the first zoölogical laboratory, or, indeed, any in general biology in this country, was established by Louis Agassiz at Harvard College, at the middle of the nineteenth century, when Wyman also taught to special students comparative anatomy. Agassiz gathered about him and trained specialists in zoölogy, most of whom became teachers and perpetuated his methods of instruction. In Europe, Johannes Müller established a laboratory at Berlin (1857-58), and trained many students, who afterwards filled chairs in different universities. The impetus he gave to comparative anatomy, physiology, and embryology through his laboratory methods was deep and lasting. He was perhaps the father of modern morphological investigations and of laboratory methods. Other zoölogists who exerted an influence which was felt by a later generation, and led the way to the establishment of marine biological laboratories, were the Norwegian naturalist Sars (1805-69), who carried on deep-sea dredgings and embryological researches on the coast of Norway: Rathke of Dorpat; and Forbes of Great Britain. During this period H. Milne-Edwards and De Quatrefages worked in temporary private laboratories on the French coast and in the Mediterranean.
The third quarter of the nineteenth century was a period of the installation of biological laboratories in connection with the leading universities, especially in Germany. The workrooms were fairly large and well lighted; but the furniture was simple, tables, dissecting implements, microscopes, aquaria, and in the basement perhaps a vivarium for mammals, forming the greater part of the furniture. Such a laboratory was that of R. Leuckart at Leipzig, who trained a large number of German, Swiss, American, English, and Dutch zoölogists and morphologists. With the rise of more modern modes of investigation in comparative embryology and morphology, involving methods of cutting their sections for the microscope, of staining and mounting them, the use of various reagents and preservative fluids, the equipment of biological laboratories became more and more elaborate and costly.
Our modern bacteriological laboratories took their rise from the researches of Pasteur in France (1866-90). His studies led finally to the establishment of the great Pasteur Institute in Paris, which was followed by the installation of bacteriological laboratories in Germany, Italy, and other European countries, as well as in the United States and Canada—institutes either directly connected with universities and medical schools, or independent. In such laboratories as these, and other temporary laboratories established in Italy, West Africa, India, and Cuba, have been worked out the causes and preventives of the filth diseases, of yellow fever and tuberculosis.
Marine laboratories have exerted a profound influence on biological science, besides training science teachers and aiding investigators. Müller in Germany spent his summers by the seaside, studying the anatomy, and especially the develop-
