178 
NATURE 
[ DECEMBER 24, 1896 
is a very grim joke, but we must bear with it and many others 
of the same kind, and in the meantime we do say that we agree 
with Dr. Lodge in his notion that our true and only natural 
foes are ignorance and prejudice. This ignorance of the needs 
of mere mechanical persons and prejudice against attempts to 
teach them, are fashionable now among scientific men. At the 
recent dinner of the Royal Society quite a genteel titter greeted 
a casual reference to technical education in one of the speeches. 
I like algebra myself, but I do not think that it is the only 
possible conventional way of making an exact statement. How- 
ever, taking Dr. Lodge’s student with his “‘true from the 
bottom upwards and entirely true,” mariner’s formula to find 
a certain academic distance ; is it quite certain that he will 
think of using it in a practical case? In my experience it is the 
very last thing that will enter his mind. I should not call him 
an ass, as Dr. Lodge does ; he only follows Plato’s maxim, not 
altogether neglected in English education, that philosophy 
ought to serve no useful purpose. The Wrangler’s naive faith, 
when he does condescend toa practical problem, is generally 
shocked in finding that such problems require the addition of a 
little common sense to the formula. Now I do not object to a 
man’s finding out the usefulness of a rule (call ita mere numerical 
rule if you like, but it is evidently a very different thing), in 
actual practical examples before he understands how it is 
derived, for lam confident that he will then be easily induced to 
inquire how the rule is arrived at; he will go further and think 
of the evidence for the roundness of the earth, and indeed it may 
prove to be the starting-point in his scientific education. I grant 
you that he will not go far if his instructor makes him begin his 
studies with the six books of Euclid. Why does the mariner 
remain so ignorant of mathematics although he uses the results 
every day? Surely he wants to know the why? Yes, indeed 
he does, but you have taught him that he cannot know the why 
unless after years of quasi-philosophic worry. 
When I spoke of the practical knowledge needed by the 
engineer, I meant to include such knowledge of physics as is 
possessed by Dr. Lodge himself ; I mean no mere pocket-book 
knowledge. Before a student can get to this higher region he 
needs to be taught to think, and it is in our notions of this pre- 
liminary training that I differ from Dr. Lodge. 
I do not care much what a man’s system of teaching may be ; 
if it is his own, however faddy, he will teach his students better 
than on a better system, not hisown. But we must acknow- 
ledge that the average teacher needs a system to be given to him, 
and this ought to be the best system. Well, I think that the 
existing system is about the very worst possible. We compel a 
student to boggle at imaginary difficulties. We worry him for years 
over four books of Euclid ; we have given up the fifth book, and 
even the supplement to the fifth, but we still worry him with the 
sixth, and then go on to geometrical conics. Now even the 
sixth book merely involves ideas which every boy takes in without 
much difficulty ; it is so natural to think of using any unit of 
length, that Dr. Lodge forgets how the ideas of the sixth book 
are needed in his simple mariner’s rule. But as soon asa student 
begins his work in physics, he is rushed over difficulties to which 
the difficulty of thinking about the mere ratio of lines is nothing. 
I do not say that he ought not to be suddenly surrounded with 
ideas of the sums and differences and ratios of all sorts of scalar 
and vector conventions for quantities, and told to sink or swim 
among them. I think this the very best thing for him ; but 
what of your consistency in mind-training, of the philcsophy of 
your methods? Dr. Lodge compels me to describe my non- 
academic way of teaching. I thought that everybody knew it, 
but evidently he does not. 
I believe in using the experimental method from the begin- 
ning ; of squares and ratios of sides of all sorts of right-angled 
triangles being figured out by the boy of eight years of age, to 
see how near he gets to tabulated sines and cosines. I believe 
in his measuring time and lines and forces with the watches and 
scales and balances which are in common use ; in testing the rules 
of mensuration of areas and volumes, and the finding of weights 
of bodies by calculation ; and it is only when a boy has a good 
quantitative knowledge from his own experience that I trouble 
him with the philosophy of mathematics and physics, and then I 
do it cautiously. I make beginners plot curves on squared 
paper—curves showing the rate of increase in the price of silk or 
cotton or the height of the barometer, or the National Debt or 
other things given in Whitaker’s Almanac—in telling them 
about the slope of a curve and its analogy with velocity and 
acceleration and dy/dx and ds/d¢ and d°s/dt*. They ‘‘ graph” all 
NO. 1417, VOL. 55] 
sorts of curves; they add and subtract vectors by actual draw- 
ing, and their lectures and laboratory work and graphical and 
numerical exercise work go on simultaneously. 
Some of my academic friends not only refuse to let a student 
use a formula, but they refuse to let him use a table of logarithms 
until he can calculate logarithms. To be consistent they ought 
to refuse the use of a watch or of clothes until a student has 
shown aptitude in the watchmaking and tailoring trades. I let 
my students use any appliance whatsoever if I think that it will 
give them a better acquaintance with natural phenomena ; any- 
thing that will cause them to think. As a student gets on I 
let him take all sorts of liberties in regard to units ; he uses w/e 
for m ; he speaks of centre of gravity instead of centre of mass 
or centre of area. 
Also, I venture to tell Dr. Lodge that the very best of my 
students, who know something of Bessel functions and spherical 
harmonics and elementary St. Venant work on the torsion and 
bending of prisms, and something about generalised coordi- 
nates, are taught to have the very highest respect for the rule- 
of-thumb practical methods of calculation in use among 
engineers. They are taught that the engineer has to deal with 
things that are by no means so simple as the ordinary laboratory 
phenomena, and that rules arrived at through the trials and 
errors of generations of practical men are worthy of some 
respect. 
Lastly, I may say that we are tired of the whole academic 
system which recognises no philosophy or literature or art which 
is not studied as)a dull grind for examination purposes, and I am 
thankful to say that we have indeed ‘‘a sympathetic faith in a 
much larger training.” JOHN PERRY. 
December 17. 
The Earthquake of December 17. 
Ir may interest your readers to know that the recent earth- 
quake of December 17 was shown slightly on the declination 
curve, and more distinctly on the horizontal force curve, at Kew 
Observatory. The time of commencement was 5h. 35m. a.m. 
(+1 minute) G.M.T. The disturbance on the horizontal force 
trace approximately equalled what would have been produced 
by a change of 0°00004 C.G.S, units in that force. 
CHARLES CHREE. 
Kew Observatory, Richmond, Surrey, December 19. 
EARTHQUAKE shocks occurred in Worcester at 3.35 and at 
5.31 a.m. on Thursday. The 3.35 shock was feeble, of short 
duration, and was noticed but by few persons. But the visita- 
tion of 5.31 exceeded in violence any previous instance of 
seismic energy here within the present century. There were in 
the 5.31 instance two shocks following each other with a bare 
interval. The shocks consisted of a series of rapid vibrations, 
too rapid to admit of count. These shocks were preceded by a 
roar as of thunder. Some describe the roar as that of the noise 
of a ‘“‘rushing mighty wind.” My house was shaken with 
appalling violence, displacing roof tiles, and forcing open a 
closed chamber door. To me the shocks seemed to proceed 
from north to south, The duration of the shocks lasted between 
four and five seconds. Some say the shocks lasted fifteen seconds ; 
but if the earthquake had lasted so long, my house would have 
been down. As it was the house was rocked to its foundation, 
and the sensation was appalling. Persons whose bedrooms. 
faced the north, saw a great light accompanying the earthquake. 
This peculiarity is by some attributed to lightning, by others to 
the effect of a large meteor. Mr. Russell Dirrell, of North 
Piddle, a place seven miles east of Worcester, saw at the time 
of the earthquake a great blaze of light low in the northern 
horizon, continuing for two or three seconds. He was unable 
to attribute the blaze to a lightning effect. At the homestead of 
Mr. Walters, of Hallow, three miles north of Worcester, the in- 
mates were thrown out of bed, as was the case in several other 
instances in the same village. Here the shocks were most 
severely felt at places on the west of the Severn. In Worcester 
the shocks created general alarm. Bells were set ringing, shut 
doors forced open, windows rattled, heavy wardrobes displaced, 
earthenware scattered about, in some instances broken, but no 
one was injured. A strong fixed wash-hand basin in a lavatory 
was split to pieces. The church clock of All Saints, on the east 
of the Severn, was stopped at 5.15 a.m. Asseems to be usual in 
such cases, poultry and pheasants flew down from their perches 
and showed signs of distress, birds flew aimlessly about and 
