THE TEACHING OF MECHANICS BY EXPEKIMENT. 
265 
could do. All the apparatus which Professor Ewing has brought with him and 
shown on the screen, and which bear evidence of such very careful design, has 
been made entirely under his supervision in the workshops at Cambridge, and such 
a condition of affairs is possible because his department of engineering at Cam¬ 
bridge, like all his apparatus, is self-contained. The engineering department at 
the ordinary college is not self-contained. The Professor of Physics teaches the 
engineering students to a considerable extent and would probably look with jeal¬ 
ous eyes upon a great many of the mechanical experiments that Professor Ewing 
has described to us to night. That possibly accounts for the difference between 
the ordinary laboratory and Professor Ewing’s laboratory at Cambridge. As 
Professor Ewing has pointed out, the ordinary laboratory consists of one big steam 
engine, one big testing machine and there you have finished. But it should of 
course be remembered that in such cases the students who go to the Professor of 
Physics undoubtedly come across a great many of the more elementary mechanical 
experiments that it is desirable they should know. At the same time there is 
probably no institution in Great Britain, whose laboratory is at all so complete as 
that at Cambridge. There a man gets all his mechanical ideas firmly fixed. 
He experiments with the steam engine, with the testing machine, and with 
hydraulic apparatus, so you can easily imagine that the experiments which Pro¬ 
fessor Ewing described are only a very small proportion of the experiments that 
the students under him do. 
There is one point with which I was particularly pleased, Professor Ewing 
mentioned, namely, the danger of the mechanical laboratory being overdone. 
In my opinion it is a danger and it is a danger which will increase in the next 
few years. You do not want a man who is becoming an engineer to depend en¬ 
tirely upon experiments and apparatus; you want him to be able to reason out, 
without any material aid in the shape of physical apparatus, what will happen if 
certain data are given to him ; and I am afraid in a great many cases the ex¬ 
tension of the mechanical laboratory can become too great. I do not refer, of 
course, to the higher cplleges, but there are a great many institutions in which 
the teaching staff is necessarily limited, and in those institutions I think the 
student will look upon the apparatus as a sort of thing that is to be experiment¬ 
ed with and there let the matter rest; in other words he will not trouble to 
reason the thing out on paper, which is essentially what engineers have to do. 
I do not think I have any other remarks to make except to express the really 
very great pleasure which I have had in listening to Professor Ewing. I take it 
that there will be a great run upon mechanical laboratories and that each of us 
will immediately turn the spare room into one, where he may experiment for 
himself—at least that to a first approximation, is what I should like to do at 
Greenwich. 
Professor A. G. Greenhill, E.R.S.: Students who have the privilege of 
attending Professor Ewing’s lectures at the university are much to be envied when we 
compare his method with that which was in vogue in my time at Cambridge. At 
that date experimental illustration was frowned upon as something tending to en¬ 
gender a sceptical mind, and a mind antagonistic to calm introspective reflection. 
In a collection of Essays on the Conflict of Studies by the late Hr. Todhunter it 
was gravely maintained that if a student doubted that a certain thing was a fact 
when he was so assured by his instructor (in most cases a clergyman of the 
Church of England) the student was not much more likely to be impressed by 
any experiments (laughter). 
The question of dilution of gravity (the phrase is Dr. Oliver Lodge’s express¬ 
ion) came up in conversation this afternoon when we were discussing the possi¬ 
bilities of a flying machine and of human flight, a subject that was brought be- 
