314 
NA TORE 
[FEBRUARY 4, 1904 
the South African fauna, and offers excellent sugges- 
tions for the purpose, he is nevertheless somewhat in 
the position of Satan reproving sin. He appears to 
have spared but little in the way of buffaloes, ante- 
lopes, zebras, or hippopotami that came in his way, 
and his beautiful photographs—over and over again— 
of his trophies make one wince at the shocking and 
needless extirpation of creatures more wonderful or 
beautiful, in their physical aspect, than their destroyer. 
A typical instance of this may be seen in the illustra- 
tion on p. 227, and it must be borne in mind that this 
collection of trophies refers to the already sorely 
diminished game of Zululand. 
An interesting chapter contributed to the book by 
Mr. Cronwright Schreiner deals with the marvellous 
migrations of the springbuck, which until recently 
used to pour down at intervals from the northern 
regions (Bechuanaland and Transvaal) over the more 
settled districts of South Africa. These movements, 
Mr. Schreiner thinks, are due to drought in the hinter- 
land forcing the springbuck to move in enormous 
numbers in search of fresh pasture. Mr. Schreiner 
himself computes the number that he saw in 1896 in 
one of these extraordinary migrations at 500,000. An 
excellent photograph is given of these migratory 
springbuck on the trek. Of course, on these occasions, 
the creatures were so massed together that flight from 
human leopards, or lions was impossible. 
There have even been occasions when men on foot, 
overtaken by one of these surging crowds of antelopes, 
have been knocked down and trampled to death. Mr. 
Findlay puts in a very strong and valid plea for a 
gigantic zoological gardens to be created by the State 
at Pretoria, taking advantage of its genial climate, 
its abundant water supply, and the fact that so much 
of the local vegetation is of a semi-tropical character. 
The book under review is well worth reading, and 
will be of permanent value as recording some excellent 
pictures of the South African buffalo, a form which, 
owing to the ravages of rinderpest and the attacks of 
sportsmen, is not very far off extinction. 
H. H. Jounston. 
beings, 
ENGINEERING SCIENCE. 
Engineering Standards Committee. No. 3. Report 
on the Influence of Gauge, Length and Section of 
Test Bar on the Percentage of Elongation. By 
Prof. W. €. Unwin, F.R-.S. Pp. 21, and 2 dia- 
grams. (London: Crosby Lockwood and_ Son.) 
Price 2s. 6d. net. 
Technical Mechanics. By Prof. E. R. Maurer. Pp. 
Xvi+382. (New York: John Wiley and Sons; 
London: Chapman and Hall, Ltd., 1903.) Price 
7s. net. 
qe first of the volumes under notice is one of the 
reports published by the Engineering Standards 
Committee, which is doing such valuable work at the 
present time, and with the very important 
question of the proper dimensions for test bars in order 
that the percentages of clongation in different sets of 
experiments can be compared with one another. The 
report is written by Prof. Unwin, F.R.S., who carried 
NO. 1788, VOL. 69} 
deals 
out a series of original investigations for the com- 
mittee in order that they might have definite experi- 
mental data before coming to any decision as to the 
proportions they would recommend for test bars. 
A brief historical summary of our knowledge on 
this question from the first enunciation of Barba’s law 
in 1880 up to the present is first given, and then the 
author describes in detail his own series of experiments 
on ship and boiler steel plates. In the body of the 
report given summary tables of the results 
obtained, and in the appendices full details of the 
various tests, while the results are shown graphically 
in the diagrams appended to the report. It was clearly 
shown by one series of the tests that serious errors are 
introduced in comparing the ductility of bars when 
the width of the cross section is kept constant, and 
therefore the cross sectional area is allowed to vary. 
In discussing the rules which might be laid down 
for standard sizes of test bars, the author points out 
the grave practical difficulties which arise in either 
varying the gauge length so as to keep the ratio 
1/,/a constant, or in keeping both gauge length and 
cross sectional area constant. He suggests that the 
best plan, from a scientific point of view, would be 
to keep to a gauge length of 8 inches, and a cross 
sectional area not exceeding 1 square inch for all 
plates from § inch to g inch in thickness, such plates 
constituting the great bullk of those tested for com- 
mercial As an alternative it might be 
advisable to specify a fixed gauge length of 8 inches 
and a width of test bar not to exceed 2 inches for plates 
lying between 3 inch and @ inch in thickness, and then 
to draw up special rules for plates lying outside these 
limits of thickness. The author, it might be pointed 
out, has lately given a much more complete account of 
this piece of research work in a paper read before the 
Institution of Civil Engineers on November to last. 
If the various reports of the Standard Committee 
are all carried out on the lines of those issued up to 
the present, they will prove of the utmost value to 
engineers and to the engineering trade of the country. 
Prof. Maurer’s volume is a text-book on theoretical 
are 
purposes. 
mechanics for engineering students, the subjects 
treated having in all cases a direct bearing on engineer- 
ing problems. It is divided into three sections— 
statics, kinematics, and kinetics—treated in the order 
in which they are given. 
In dealing with statics, the author adopts freely both 
graphical and analytical methods, and we strongly 
approve of this plan, as it has always appeared to us 
most unwise to divorce these two methods of treatment 
of statical problems; if properly handled together they 
greatly assist the beginner in overcoming some of 
the notorious stumbling-blocks in this branch of 
mechanics. A particularly useful chapter in this 
section, both for teacher and student, is vi., in which 
a series of practical problems involving the application 
of the principles of equilibrium (worked out in earlier 
chapters) are dealt with both graphically and algebra- 
ically; the examples cover such cases as flexible cords 
in tackles, jointed frames, and friction in screws, pin 
joints, belts, &c. 
Kinematics is treated mainly from the point of view 
