One of the most serious hindrances to increased success is the unduly large size of many of the sections for recitation. The average number per section is too large for fully effective work, and the necessities of the tabular view cause so much inequality in division that certain sections are very unwieldy. With additional instructing force this difficulty could be remedied, provided, of course, that recitation rooms are available to accommodate the increased number of classes. The new system of individual conferences, commenced since the opening of the present school year, gives promise of great benefit from the more intimate relations which it necessarily established between teacher and student.

The experiment begun several years since, of giving special brief courses of illustrated lectures with attendance voluntary, in order to discuss certain newer branches of physics more particularly than is possible in the required course, has proved entirely successful. A course upon Hertz waves and wireless telegraphy was given for the first time in the second term of last year. This was attended by a large number of students whose interest was maintained to the end of the term. A course of like character in polarized light is planned for the autumn of 1909. It is intended that each of these courses shall be given once in two years.

The lectures in heat, fifteen in number, given to all students in the third year have been made somewhat more experimental in their character than was formerly the case. As there are numerous thermal processes and applications, however, which are highly important in certain branches of applied science, Professor Norton, who is in charge of this subject, has laid out a brief special course of technical lectures devoted particularly to such industrial applications of heat.

In the revised course schedules now in effect in the second and third years the long desired arrangement of bringing the laboratory work into closer connection with the class room work in Physics has been effected for all courses except those in Mining and Chemical Engineering. The laboratory work

now begins at the middle of the second year and ends at the conclusion of the course in heat in the third year. An immediate result of this arrangement has been a much greater interest on the part of the students and far more effective work, to which the correlated class room instruction in precision of measurements now given at the beginning of the laboratory work has contributed in no small degree. The Department is very desirous that the time devoted to the laboratory may be increased for all courses by the addition of fifteen hours in the first term of the second year, in order to bring this work into still closer connection with the lectures and to make possible the introduction of a number of electrical experiments in connection with the lecture and class room work in electricity.

In connection with the general laboratory instruction Professor Goodwin has prepared and printed a brief treatment of the subject of precision of measurements and allied topics, and also a new part of his "Laboratory Notes on Optics." A new edition of the "Laboratory Notes on Heat" has also been issued.

An advantageous modification has been made in the Course leading to a degree in pure Physics in the arrangement of the study of theoretical physics, in charge of Dr. Daniel F. Comstock. There is now given a continuous course extending through the whole third and fourth years, beginning with dynamics, occupying a year, which is succeeded by a somewhat advanced course in electrostatics and electrokinetics. Courses in optics by Dr. Comstock and on energetics and the kinetic theory by Professor Goodwin are also given in the fourth year as heretofore.

Aside from the completed investigations, the results of which are embodied in papers already published (see p. 137), a research by Dr. Herbert T. Kalmus, still in progress, should be mentioned in this place. A study of the effect of the ultraviolet radiations of the cadmium spark, when this is of very great power, upon chemico-physiological action and bacterial growth has given results which promise to be of much importance

when fully verified by longer experimentation. For these studies of Dr. Kalmus, the Zeiss ultra violet apparatus has been employed in connection with the powerful induction coil made for the Institute by Heinze of Lowell.

Attention ought also to be called to the investigations regarding the physical properties of concrete throughout wide ranges of temperature, which have been in progress in the laboratory of heat measurements for a year past. This investigation concerns a very important subject since it relates to the properties of a new and important building material whose action under great thermal changes is as yet little understood. The research referred to has been carried on by Mr. Armen H. Tashjian, at present Assistant in heat measurements.

Much new apparatus both for lecture room and laboratory work has been procured during the past year. A very considerable addition has been made to the collection of vacuum tubes, and much miscellaneous mechanical, acoustic, and electrical apparatus has been procured, in part by purchase and in part by construction in the workshop of the Department. In particular, the apparatus for illustration of the lectures on heat has been largely increased. Especially worthy of mention are also several devices for the study of electric waves, those of Lecher and of Coolidge (one of our own graduates) for producing waves in wires. For generating electric waves in space an electric arc lamp of particular construction with needed accessories has been designed by Mr. Eugene D. Forbes of our instructing staff and constructed by the Department mechanician, Mr. Thomas Cloonan. This apparatus is particularly intended for the investigation of wireless telegraphy and telephony.

An important instrument which will be of particular value to the students in Mining and Geology is the Zeiss crystal reflectometer for the investigation of the optical properties of small crystals. This was purchased from the Katharine Bigelow Lowell Bequest. A Brace spectrophotometer has been ordered from Schmidt & Haensch, of Berlin, which will form

an important addition to the apparatus of the optical laboratory.

For the instruction in physico-chemical measurements the latest types of Beckmann boiling and freezing point apparatus have been added, together with apparatus for the determination of critical constants and dielectric constants. The extensive equipment for studies of this character is such that students electing this course have a wide latitude in the choice of work which they may pursue.

In the laboratory of electro-chemistry the most important additions made during the past year have been a new carbide furnace, a Sturtevant crusher, a thermit outfit, and a Féry radiation pyrometer, for the measurement of furnace temperatures. It is hoped that the power available for the work in applied electro-chemistry may be increased during the coming year. The limit of the 30 kilowatt alternator furnishing power to the laboratory has already been reached. With the rapid development of electro-chemistry more time each year is needed for laboratory instruction, especially in high temperature processes.

Our exceptionally extensive collection illustrating the various processes of color photography has received a large increase of lantern slides made by Professor Derr and presented by him to the Institute. These illustrate the new Lumiére and other processes not only as applied to ordinary subjects, but also in their application to micro-photography and to the reproduction of the chromatic phenomena of polarized light. Certain other slides are designed to illustrate the theoretical and practical limitations of color photography in its present stage of advance

ment.

Since the date of the last Report the Department has received several valuable gifts which are very fully appreciated. Among these should be particularly mentioned a fine compound microscope by Tolles with objectives and accessories from Dr. William Rollins, and also a Geryk air pump from the same donor. Professor Norton has presented to the laboratory of

heat measurements, of which he is in charge, a Callendar electric temperature recorder, which gives a continuous record of high temperatures, as, for example, those of a pottery kiln or an annealing furnace. This instrument, made by the Cambridge (England) Scientific Instrument Co., is the most delicate and beautiful of modern temperature registering devices. There has also been received from Mr. George Wigglesworth, late Treasurer of the Institute, a generous gift which has enabled the Department to be assured of skilled assistance in the preparation of the lectures, to the great advantage of teachers and students alike.

CHARLES R. CROSS.

DEPARTMENT OF GEOLOGY.

The two most important changes in the work of the Department of Geology in 1908 have been the rearrangement of geological schedules for students of Civil and Sanitary Engineering and the enrolment of an unusual number of graduate students in geology, working for higher degrees. Of the latter, one has been appointed instructor and another assistant in the Department, with the understanding that one-half of their working time be given to study and investigation. Three of the graduate students are candidates for the degree of Doctor of Philosophy. Advanced work in the petrographical laboratory has been carried on by Mr. George W. Edmond, who spent seven months of the winter and spring in exploration of the wild desert region of Lower California north of the 29th parallel of latitude.

Mr. Waldemar Lindgren, M.E., Geologist in charge of the sections of Mining Geology and Metal Statistics of the United States Geological Survey, has been appointed lecturer in Economic Geology for 1908-09, to succeed Professor Kemp. He has secured leave of absence from Washington for five weeks in the late autumn; and during this time, while resident in