JuNE 8, 1899] 
NATURE 
123 
Accordingly, after a brief introduction, M. Olivier dis- 
cusses the representation of the point, the straight line, 
and the plane, and the elementary problems relating to 
them. What is offered instead of this to the English 
student? Rules for finding the plan and elevation of an 
equilateral triangle, of a cube, octahedron, &c., in various 
specified positions, with a very few really fundamental 
problems apologetically inserted here and there. Now 
although the representation of a few concrete solids may 
be useful to help the beginner to see the object of 
orthogonal projection, a text-book wholly, or almost 
wholly, devoted to such special problems is of very little 
use, except for the passing of examinations set exclusively 
on these lines. 
Similar remarks might be justly applied to most of our 
books on practical plane geometry and perspective. The 
almost invariable rule is to give a more or less numerous 
set of isolated examples, all worked out, with as little 
discussion of principles as possible: the result is that 
the student, instead of being provided with a powerful 
instrument capable of endless adaptation, is merely 
acquainted with a bundle of dry practical rules. 
The works which have suggested these observations 
are by no means the worst of their class: on the con- 
trary, they are much better than the average, and mark, 
it is to be hoped, a movement in the direction of reform. 
Captain Atkinson’s book is intended chiefly for the 
Royal Military Academy, and its scope has doubtless 
been dictated by this consideration. Its principal merit 
is that it contains three chapters on horizontal projection 
(z.e. the method of an indexed plan) which really do give 
a useful and practical outline of this method in an 
orderly way. Most of the elementary problems are 
solved, and the examples appear to be well chosen. It 
would have been a good plan to give the data of some 
unworked problems graphically instead of stating them 
allin words. The earlier part of the book is less attrac- 
tive ; it contains a bare outline of orthogonal projection 
and a few miscellaneous notes on regular solids, ways of 
drawing an ellipse, &c. The book ends with a sketch 
of the method of isometric projection. The plates are 
clear : unfortunately they are printed on folded sheets, 
and bound up at the end of the book ; this makes it very 
difficult to follow a figure and the text relating to it 
simultaneously. If the plates were bound separately the 
convenience of the work would be greatly increased. 
Mr. Plant discusses a great variety of problems, which 
have been arranged in groups in a fairly systematic way. 
The figures are from photographs of actual drawings by 
the author and his assistants, and so afford the student 
a real practical standard of accuracy. The book is 
likely to be very useful to the classes for whom it is 
intended : at the same time, there are several points on 
which it appears to us rather open to criticism. 
In the first place, the attention given to different groups 
of problems is not proportional to their importance. At 
least half of the problems in sections G to K might have 
been set as exercises ; this would have given space for 
a discussion of similar figures—an important subject 
almost ignored. 
Again, the use of set squares for drawing parallels 
receives no attention, although these instruments are 
NO. 1545, VOL. 60} 
casually mentioned in the introduction. Nothing is 
more essential to the draftsman than familiarity with the 
use of set squares ; compass constructions (such as those 
given in this book) for drawing parallels and perpen- 
diculars are seldom used in practical work. 
In a similar way, the use of the protractor for setting 
off angles is not sufficiently brought out. There is 
actually a section on the construction of certain special 
angles (such aS 67° 30’) without a protractor. The 
section on regular polygons is specially unsatisfactory : 
there may be some sense in giving an accurate compass 
construction for a pentagon, but what earthly use is 
there in giving zzcorrect constructions (e.g. for the 
heptagon, p. 30 and elsewhere) which only afford an 
approximation obtainable much more simply by means 
of a protractor or scale of chords, or even by a method 
of trial? It may be added that these approximate con- 
structions are given without any warning of their real 
inaccuracy. 
Finally, there are a good many examples of no practical 
importance: for instance, group J is “To inscribe a 
square in all(!) the figures capable of containing it.” Of 
course when questions of this kind turn up as Euclid 
riders, it is a good thing to make a schoolboy draw an 
accurate figure ; but to include them in a text-book of 
practical geometry is waste of space. 
The fact is that ideal treatises on practical geometry 
in all its branches, for the use of English students, have 
yet to be written. Ordinary plane geometry, orthogonal 
projection, perspective and projective geometry—all 
these are methods of extreme value, both to the mathe- 
matician and to the engineer, when they are really 
mastered ; but a mere smattering is of very little use. 
Unless you know thoroughly the elementary principles 
involved, the solution of hundreds of isolated examples 
is little better than waste of time: here, as elsewhere, an 
ounce of theory is worth a ton of “practice” of the 
usual kind. Real practice, of course, is indispensable ; 
but it should be systematic, and illustrate principles of 
general application. GaBsaM: 
OUR BOOK SHELF. 
Michael Faraday: His Life and Work. By Silvanus P. 
Thompson, D.Sc., F.R.S. Pp.ix + 308. ‘‘ The Century 
Science Series.” (London : Casselland Co., Ltd., 1898.) 
THE lives of men to whose genius and untiring devotion 
to research the stately edifice of modern science owes its 
existence, have a fascination and an interest which appeal 
to a much wider circle than that of the few who are able to 
realise the full significance of their epoch-making scientific 
discoveries. Even those to whom science is little more 
than a name are capable of feeling a keen interest in 
everything that concerns the purely human element in the 
lives of the great leaders in science. Hence there has 
arisen a demand for biographical literature of this type, a 
demand which the “Century Science Series,” to which 
the volume before us is the latest addition, is intended to 
meet. 
Of all the great names in the history of science which 
have become household words in civilised communities, 
that of Michael Faraday will always stand out pre- 
eminently as that of one in whom genius was wedded toa 
childlike simplicity and transparent sincerity of character 
but seldom found in association with such remarkable 
