NEMO RE 
[ApriL 8, 1897 
students who have used the notes from which it is 
written. In this way it is possible for them to feel 
certain that, whatever may Le the failings of their work, 
it will at least be intelligible to the average student. 
The book opens with a preliminary chapter called 
“General Instructions,’ and the practical teacher at 
once becomes apparent in such paragraphs as that on 
the importance of /avge errors. No one can have had 
much experience in teaching practical physics without 
seeing that the anxiety of beginners to obtain correct- 
ness in the second or third place of decimals is accom- 
panied by an extraordinary laxity in noting the tens and 
hundreds. In fact, it may be said that most of the 
inaccuracy of beginners in physical measurement is due 
to this cause. In the chapter on “ Arithmetical Calcu- 
lations,” the authors rightly lay stress on contracted 
methods of multiplication and division. The short 
chapter on “ Graphical Constructions” is less satisfactory 
than the others, and would probably be improved if 
some better examples of the method were employed, 
and if some notice were given to the convention (a 
most useful one) of making abscissa represent the 
independent, and ordinates the dependent, variable. 
The body of the book is taken up with experiments 
on mechanics (including measurement of density and 
specific gravity), heat, light, sound, and electricity. As 
necessarily follows from the nature of the case, there is 
not much that is original in the treatment of these 
subjects. One admirable feature, however, which runs 
throughout the course, is the working out of the per- 
centage error in each experiment. In the section on heat, 
we notice that the calorimeter equivalent is found by 
pouring warm water into an empty calorimeter ; more 
satisfactory results can generally be obtained by pouring 
warm water into a calorimeter containing some water 
at the temperature of the room, and calculating the 
difference between heat given out by warm water and 
that taken in by the cold. In this section is also to be 
noticed an ingenious form of heater for the determination 
of specific heats by the method of mixtures. 
In the optical section the method of tracing rays by 
means of pins—first used, we believe, in the Cavendish 
Laboratory—is employed to a considerable extent. 
There is an experiment on the power of accommodation 
of the eye, which we have not seen before in any similar 
work. 
The section on “sound” is concerned with the proof 
of the laws of vibrating strings, and an experiment on 
the resonance of a column of air. In the last three sec- 
tions of the book, on “magnetism,” ‘electric currents,” 
and “electric charges,” the authors seem to be less 
successful than in the earlier parts. But it is éxtremely 
difficult in the course of fifty pages to give a satisfactory 
series of experiments on these subjects, especially when, as 
in this case, a very large number of those pages are taken 
up with elementary explanations which might have been 
omitted by reference to any text-book, such as that of 
Thompson. And the form of water voltameter described 
is hardly, one would think, the most useful for laboratory 
purposes, or the most instructive from the point of view 
of the teacher. 
In conclusion we may be permitted to suggest that, 
from an educational point of view, the book would gain 
NO. 1432, VOL. 55] 
if at the beginning of each experiment a short and clear 
statement of the object of that experiment were given. 
One of the most useful results to be obtained from a 
‘laboratory course such as this is gained when the student, 
knowing clearly the question which he is to address to 
nature, thinks out for himself how he is to proceed in his 
cross-examination, and compares his method with that 
of an experienced investigator. ID}, 18, 
OUR BOOK SHELF. 
Bis ans Ende der Welt! Astronomtsche Causerien- 
By Prof. F. J. Studnieka. Second enlarged edition. 
Pp. 212. (Prague: F. Simacek, 1896.) 
THE author of this book went to Karlsbad to indulge in 
the special opportunities afforded by that town in the 
nature of its waters. During his stay there he made the 
acquaintance of several other “ Kurgaste,” by name 
Bausen, Bugajev, Carpenter, Parell1 and Place, and his 
two friends from Prague, Benda and Naprstek. To. 
pass away the time of their sojourn, these persons formed 
a small social circle, and, besides taking drives to- 
gether, they met at stated times and discussed any 
subject that was uppermost in their minds. Carpenter, 
however, seemed, from all accounts, to be the dominating 
one of the party from the discussion point of view, and 
being of an astronomical turn of mind, the conversations 
generally were on this subject. His listeners were 
members of several different professions, so the subject 
had to be treated in an elementary manner, and, in 
consequence, the explanations had to be very clear. 
The author of this book, who was one of the party, 
describes here the daily conversations which took place; 
they are mainly astronomical, although other subjects 
are occasionally referred to. The astronomical and 
physical problems dealt with are, for the most part, of 
a very general character, and will be found interesting 
reading. 
A trip to Prague, after the stay in Karlsbad, gives the 
author a chance of referring somewhat in detail to the 
associations, works, and lives of Copernicus, Tycho: 
Brahe, Kepler, Doppler, &c., all of whom were intimately 
connected with that town. 
The book may be said to be quite suitable for the 
general reader, and the numerous diagrams and illustra- 
tions scattered throughout its pages will prove serviceable. 
First Stage Inorganic Chemistry. By G. H. Bailey, 
D.Sc., Ph.D. Edited by William Briggs, M.A. Pp. 
210. (London: W. B. Clive, 1897.) 
IT is too often forgotten,when criticising text-books written 
to follow the lines laid down in syllabuses, that the books 
are not so much to be blamed as the syllabuses. For 
convenience, it is considered necessary to state the sub- 
jects of which a student who presents himself for exam- 
ination will be expected to know something. The text- 
book is then produced, in order that the student shall be ' 
able to acquire the knowledge in as easy a way as 
possible. 1f the syllabus is badly arranged, the text-book 
designed to meet it will be a bad one ; but if the subjects 
in it are placed in an educational sequence, the text-book 
will partake of that good quality. Probably no one is 
better able to judge whether a syllabus hangs together 
properly or not, than a competent scientific writer who 
tries to build a book upon it. 
The book before us has been arranged to meet the 
requirements of the Department of Science and Art for 
the Elementary Stage of Inorganic Chemistry. In 
eighteen short chapters the author deals with the general 
principles of chemistry, the nature of chemical reaction, 
the chief non-metals and their most important com- 
pounds, physical properties of gases, chemical nomen- 
