576 INTERNATIONAL CONGRESS OF EDUCATION. 
are based and is unable to deduce his own formule, is a dangerous man to 
be trusted with responsible work, and that just as there is no royal road 
bo learning, so there is no means by which formule can be substituted for 
a knowledge of principles. 
Turning now to a consideration of the constants to be used, the fact is 
that it is only within the last fifteen years that a great deal of activity has 
been displayed in testing the strength of pieces of practical size, and under 
conditions imitating closely those of practice, and that a flood of light has 
been thrown on the question as to what are and what are not reliable 
constants to use in practice. Of course, calculations based upon incorrect 
constants cannot give rise to safe structures and machines. What I have 
said is enough to show how very important it is that the study of strength 
of materials, both the mathematical and experimental portions, should be 
rery thorough and in detail. 
The next course to receive our attention is thermodynamics and steam 
>ngineering. It might be assumed by some that this was peculiarly the 
province of the so-called mechanical engineer ; but that it is the province 
of every engineer of whatever name, becomes evident when we consider 
that steam is the principal source of power, and that without power all 
the works would have to shut down. 
Now, let us consider how such a course should be laid out—assuming, 
of course, that the student is already familiar with valve gears and with 
she mechanism of the steam engine ; also assuming that he has had a 
sourse of heat in his course in physics, and that, in this course, he has 
seen taught thermometry, calorimetry, and the laws of the transferrence 
Of heat. 
He should then be taught the nature and construction of the steam- 
engine indicator, how it is to be used, how the indicator card is taken, 
and what it means, and he should acquire some familiarity with inter- 
preting the characteristic and also some of the peculiar features of indi- 
sator cards; and then he should know the general characteristics—u.e., 
sutward characteristics—of the different types of steam engines. 
Next he should receive a thorough drill in the principles of thermo- 
dynamics. What is thermodynamics, and what kind of a course should 
our prospective engineer have in the subject ? Thermodynamics is sim- 
ply the mechanical theory of heat, or, in other words, the science of 
heat with special reference to the production of motion. The subject 
was originally developed from the standpoint of the mathematical physi- 
cist, and books have been written from this point of view by such men as 
Olausius and others. Besides the fundamental principles of the science, 
they take up elaborate discussions of the nature of heat, and a large mass 
of applications and developments in the direction of pure science rather 
than in the direction of what we need in the study of the steam engine, 
or of other heat engines. as the gas engine. the hot-air engine, etc.