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just one plain simple thing until he got through with that subject. The result was said to be tiresome by critics of the school. It was nothing of the kind. There was a little study in the morning, a little scientific recreation in the afternoon-the afternoon always given to some practical work, some laboratory work, drawing, etc., sufficient to teach the student at least the fundamentals of the tools he had to work with. He was always at one subject until he got through, and when he got through with it he generally knew it pretty well.

PROFESSOR MANSFIELD MERRIMAN: In listening to these very interesting discussions regarding the conduct of laboratory work, I have been impressed with the large amount of labor spent by instructors to systematize the work and prepare the necessary plans in order that the student may derive benefit from them. It may, indeed, be thought by some that in many instances the greater part of the mental work is done by the instructor and that there is not much left for the student. There are blanks for every stage of the work, and it is sometimes carried so far that there is a blank at one machine on pink paper and at another machine on brown paper. On each piece of paper there are lines half-printed and the students regards it as an academic exercise to fill out the dotted portions. This is probably an extreme view to take of the matter. If the student should come into the laboratory with the oldfashioned, small engineer's field book with horizontal and vertical lines on opposite pages, and be required to take down notes from the experiments and bring in the next day his own report in the way he thinks it ought

to be arranged, it might be more advantageous to him in developing his power of thought. In large classes, however, such a plan would be impracticable, and it may be said in favor of carefully prepared blanks that they give training in system and order. The papers that have been read hence present excellent solutions of the problems forced upon us in handling large numbers of students, and it must be said that great credit is due to instructors in laboratory work for the systematic methods which they are developing.

PROFESSOR GAETANO LANZA: Only two of the matters mentioned in the interesting and valuable paper of Professor Hatt will be referred to here. First, every competent teacher must constantly put forth his best efforts to make the students think for themselves, and the more completely he can accomplish this object, the greater will be the success attendant upon his teaching; as the student who only memorizes and does not think, is not competent to undertake the solution of such new problems as are constantly liable to arise in the practice of his profession. Second, the object of a graduating thesis is, to my mind, to teach the student how to make investigation. I prefer that the student should, if feasible, select the subject himself, the professor, of course, advising him, and not allowing him to take up a subject in which it is not possible for him to do good work. Then a student should, with the advice of the professor, map out a plan for carrying on the investigation, which, again, the professor should pass upon, and when the plan is properly arranged the student should perform the work.

MR. BRADLEY STOUGHTON: One thing which you, Mr.

President, have so well said at this meeting already, interested me very greatly, and I desire to refer to it again. That is, the propriety of studying, not the details of any practice, but the principles upon which that practice rests. It seems to me that, in this way, we should find a solution of the various questions we have been discussing here this evening. A student mind is a limited vessel, and if one tries to fill it too full, and especially too full of details, it begins to spill and leak very fast, so that the amount of knowledge which escapes is altogether disproportionate to the amount which remains. In our over-crowded laboratories it is a great temptation to adopt printed laboratory blanks, routine methods of instruction and systems which enable us to put a number of students through the motions of many tests in a limited time. But is this the best method of concentrating their attention on the principles which we desire them to absorb? True, they become momentarily acquainted with many details, some of the least important of which are repeated several times, but it gives them neither the encouragement nor the time for independent thought which alone impresses them with the underlying principles of their occupation, but which almost every man finds at first both tedious and unattractive.

PROFESSOR WILLIAM KENT: We have heard a good deal lately of teaching principles and not details. In order to get a correct knowledge of principles close attention should be given to details. One of my students had a knowledge of the principles of the connecting rod, but about the details all he knew was that it is a bar with two holes in it. He didn't know anything

previous week, thus enabling a comparison of the yield points in tension and compression.

After this preliminary study of definitions, prin

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ciples and materials, the class is ready for the more specific consideration of each material by itself. It must not be forgotten in this connection that nearly all our computations regarding stresses in materials are based upon the principles of elasticity with stresses below the elastic limit. It is not sufficient, then, to consider only ultimate strengths. The elastic limit, and the more or less perfect elasticity of the material, as well as its behavior throughout the whole range of stress, should be made the subject of careful study. The student needs to be brought face to face with these principles and qualities, again and again, until they become a part of his unconscious possession, guiding his judgment, giving form to his expression.

Timber seems to offer many advantages as the material first to be considered. It is one of the most common materials of construction. The specimens are easily prepared and cheap. The deformations under stress are relatively great, and, therefore, readily measured. The strengths and elasticities vary in different directions with reference to the grain, thus requiring fuller investigation as well as clear ideas as to direction of stress. The strengths are subject to many variables, and yet, by controlling these variables, or by recognizing their presence, consistent and highly instructive results may be obtained.

Beginning the subject of timber, the first laboratory period is devoted to the examination of the minute structure of wood as revealed by the microscope in transverse, radial and tangential sections of the common hardwoods and softwoods; this being the basis for explaining so many of its strength, grain and shrinkage

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