274 INTERNATIONAL CONGRESS OF EDUCATION. 
ways of designing and making those in use to-day, the ways of construct- 
ng them, and their adjustments. 
The next course of which I shall speak is one which vitally concerns the 
angineer at every turn, and therefore one in which it is absolutely necessary 
shat he should be very thoroughly drilled—I refer to theoretical and 
applied mechanics. This term has been used in different senses at differ- 
ent times and in different places, but, in the sense in which I shall use it, 
t includes a general and mathematical discussion of the action of forces 
apon bodies at rest or in motion, and also a full treatment of the strength 
and elasticity of the materials used in construction, both from a mathe- 
matical and from an experimental point of view. To speak more in 
detail, it includes such subjects as the following, viz. : Composition and 
resolution of forces, condition of equilibrium, determination of the centers 
of gravity of lines, of areas, and of solid bodies; the general laws of 
dynamics, as a treatment of uniform and varying motion ; the pendulum ; 
determination of moments of inertia and of centers of percussion ; the 
aws of friction, determination of the work used up in friction, both by 
nathematical calculation and by actual experiment, ete. 
Then come the determinations of the stresses in the different members 
of trusses of all sorts ; and then a study of the mathematical discussion of 
the theories of the strength and elasticity of materials—d.e., study of the 
distribution of the stresses acting in tension rods, struts, or compression 
pieces, beams or other pieces bearing a transverse load ; also in all sorts of 
pieces that are subjected to shearing, including, of course, riveted joints, 
shafting, and beams, as well as in other pieces; the distribution of the 
stresses acting in a hook or in any tension or compression that has to bear 
an eccentric load ; the modes of determining the deflections of beams, 
she angle of twist of shafts, or the amount of yielding of pieces generally 
ander load ; theories and modes of calculation of the stresses at different 
oarts of continuous girders ; determinations of the stability ef, and of the 
stresses acting in, arches which bear a load, whether of stone or of iron; 
stability of domes, and a study of the theory of elasticity. Then, turning 
to the experimental side, the student should be made familiar with what 
experiments have been made, and with what results they have shown as to 
the strength and the stiffness of such pieces as are used in construction 
to bear a load. Moreover, the account of these experiments should be 
brought up to date, and special emphasis should be laid on the results of 
those experiments where the conditions of practice as to size, manner of 
loading, and treatment generally have been exactly, or at least approxi- 
mately, copied. The student should be made to study carefully the actual 
results that have been obtained in these experiments; to collate and com- 
pare, and to draw from them such conclusions as are warranted ; to see 
how far and in what ways they may modify the ordinary mathematical 
calculations and the ordinary ideas in regard to the action of such pieces