Lessons on Elementary Physics. 
Dec. 29, 1870 | 
NATURE 
163 

The same confusion may be predicated of almost every 
subject that can be taken up for inquiry. And, in spite 
of the multiplicity of societies, there is greatly needed 
throughout the length and breadth of the land a network 
of intelligent observers. We propose, as aremedy, that 
the present chaotic want of system be superseded by a 
National Institute for the Advancement of Knowledge. 
Such an institute might readily be obtained by the amal- 
gamation of the present societies into one homogenous 
body. Whatever of interest and of value British savants 
might bring before it would be welcome and appropriate, 
and would be accessible to the student of the “ knowledge 
which is one.” In its organisation, the first labour would 
be the classification into sections. Whilst, on the one 
hand, there would not be three or four sections to perform 
the same work, on the other hand the entire domain of 
human knowledge could be fairly occupied, which is not 
the case at present, and the divisions marked with much 
greater accuracy than is now possible. The members 
residing in each district would form a local section, 
hold their meetings at regular intervals, and be a 
committee charged to watch over and promote the inte- 
rests of Science and Learning in their particular neigh- 
bourhood. 
In this brief and necessarily imperfect outline, much is 
omitted. Advantages not here indicated would result from 
the creation of a National Institute for the Advancement 
of Knowledge, but it is hoped that enough has been said 
to prove the desirability of such a foundation, having for 
object the attainment (in the words of Bacon) of “the 
knowledge of causes and secret motions of things ; and 
the enlarging of the bounds of humane empire to the 
effecting of all things possible.” 
WILLIAM E. A, AXON 


PROF, BALFOUR STEWART’S ELEMENTARY 
BILL SIGS: 
By Balfour Stewart, 
LL.D., F.R.S. (London : Macmillan and Co.) 
HIS is a bold experiment, and decidedly deserves to 
be a successful one. Nearly all our elementary 
works, even on mere departments of Physics, are ex- 
tremely bad, especially the so-called “ original” ones ; 
and those which have been translated from the French 
are little suited to the genius of this country—however 
excellent they may bein France—while they are usually 
spoiled by inaccurate translation, or by clumsy and inju- 
dicious addition of a mere cobbling or patching kind. 
The reasons are not far to seek. It is very rarely that 
we find in this country a genuine scientific man who can, 
like Faraday or Herschel, make himself easily intelligible 
even on difficult subjects to an ordinary reader ; still 
more rarely that we find such a man to have paid such 
special attention to the merest elements of his subjects as 
to thoroughly understand them himself, which ought to 
be regarded as an absolutely indispensable preliminary to 
his teaching them to others. Take for instance the ques- 
tion of the measurement of temperature in conjunction 
with the second law of thermodynamics, that very second 
law itself, or its connection with the equality of radiating 

and absorbing powers. Take even a simpler matter, the 
notion of a standard pound as a definite quantity of matter, 
not as something which shall be attracted by the earth 
with a certain force. Try all the elementary works in 
succession, and, if you are not driven mad by their incon- 
sistencies and want of definiteness, endeavour to give in 
a clear, intelligible form the result of your studies on any 
such questions as those just mentioned. If you had no 
notion to begin with, you will have none, or worse than 
none, at the end ; and, even if you began with thorough 
knowledge, you would probably end helplessly confused, 
doubting the simplest and most obvious truths. But this 
is the way we do things at home ; and hard, indeed, must 
be our British heads, which, after they have managed our 
“As in presenti,” &c. &c., can plunge into this further 
chaos, and rise, as they often do, refreshed and invigorated 
by the struggle. A Frenchman, perhaps even a German, 
would perish in the attempt. But for them the path is 
made comparatively easy. 
Nothing seems plainer than this—that he who has been 
ill-taught in the elements of his subject, however he may 
advance in knowledge (which is always a man’s owx 
work, whoever be his teacher), can hardly hope to under- 
stand these elements well enough to teach them to others. 
They have become to him a hateful thing, so he pushes 
on and avoids them as much as possible. Hence, that we 
may have really elementary works of a strictly scientific 
kind, we must have, not merely a genuine scientific man 
to write them, but one whose elementary instruction was 
good, or one whose strength has enabled him to get over 
its imperfections. These qualifications are certainly 
united in Dr. Stewart, for he had the late Principal Forbes 
for his teacher, and he is himself a man of quite excep- 
tional powers, both in experiment and in reasoning. 
It is scarcely possible to form a judgment as to the 
probable success of the present work. It is so utterly 
unlike anything to which we have been accustomed, that 
we can only say we never saw such a work, in English, at 
all events. Nothing so perfectly elementary, and yet 
throughout so intensely suggestive, have we ever met with. 
Even while reading the introductory chapters, we have 
several times laid down the book to follow trains of 
reasoning suggested by a single happy phrase that 
showed us something with which we had considered our- 
selves familiar, from a perfectly novel and interesting 
point of view. This, of course, will not strike the be- 
ginner, neither will it impede his progress ; for it is not 
learned and abstruse disquisition or discussion, it is simply 
the clear vision of the writer. 
Dr. Stewart does us much more than justice in the Pre- 
face, for he exaggerates the importance of a few sugges- 
tions of ours, made only with the view of keeping him to 
his own plan, which we consider to be an admirable one. 
The grand modern ideas of Potential and Kinetic Energy 
cannot be too soon presented to the student; he ought to 
be familiarised with them as soon as he commences the 
study of Physics. In fact, we believe that before many 
centuries have passed, perhaps before fifty years have 
elapsed, the word Force will have become as much a 
nuisance and an impediment to the beginner in Physics 
as the phrase Centrifugal Force is already. 
However this may be, the work before us is an excellent 
one, and will certainly (¢ there be teachers found sufficiently 
