564 
Sufficient has been done, however, in this respect to 
make its omission from Dr. Aberg’s book a serious 
blemish. This can easily be rectified in a later edition 
by the addition of a further chapter. 
Dr. Aberg is to be congratulated on his excellent 
work, which indeed well repays a careful perusal. 
M. C. Burxirr. 

A Railway Manual. 
Manuel des chemins de fer. Par J. Bourde. (Biblio- 
théque Professionnelle.) Pp. 444. (Paris: J.-B. 
Bailliére et fils, 1922.) 12 francs. 
\ BOURDE’S book is intended for workers who 
. are desirous of extending their knowledge over 
larger fields than is covered by their actual every-day 
work, and for whom the big special volumes are in- 
accessible or unintelligible. The author is of opinion 
that the workman is too often condemned to be a mere 
wheel in a mechanism, and that he is not allowed 
sufficient initiative. The series of volumes to which 
our author’s book belongs is intended to furnish oppor- 
tunities for the workman, and each of the 150 volumes 
has been written by an author who has special know- 
ledge of the subject on which he writes. The reason for 
the lack of works of this type in this country is probably 
connected with the difference between the French and 
English people in their mental characteristics and in 
their education. The English are of course intensely 
practical, and not at all bookish. It is not implied 
that the French are not practical, but they have 
been brought up more on the bookish side than 
English engineers. The present writer knows one 
railway engineer who is—or was—anxious to write a 
book on railways, and he had accumulated a great mass 
of material. His lack of literary skill and the immense 
volume of his own knowledge will, however, in all pro- 
bability prevent the completion of the book. 
The volume under review, dealing with railways 
from the engineering point of view, covers the ground 
very thoroughly ; it is written in plain language and 
gives the essentials to such an extent that a person 
having already a practical acquaintance with any one 
branch of railway work would, by the aid of the book, 
readily fit himself to deal with problems outside his 
own special domain. 
With regard to the details of the book, a beginning 
is made with surveying and levelling, the drawing of 
plans and representation of heights by contour lines 
and other methods. With this preliminary the author 
is in a position to tackle the general design of the railway 
line, including questions of traffic, gauge of rails, 
curves, and gradients, all from the most general point 
NO. 2791, VOL. I11]| 
NATURE 


[ApRIL 28, 1923 
of view, and so as to decide on the best route. Other 
chapters discuss, from the same point of view, transition 
curves, cuttings and embankments, the calculation of 
earthwork, the latter subject being treated in con- 
siderable detail; also the problem of the economical 
arrangement of excavation and embankment, con- 
sidered especially with respect to length of haul. 
Assuming now that the actual route is decided upon, 
the author treats of the detail design and carrying out 
of the work, this portion of the book taking up more 
than one half of the whole 444 pages. There are six 
chapters treating in succession of the design and 
execution of cuttings and embankments, bridges, 
viaducts, culverts, and tunnels; then follow two 
chapters on masonry works with a general discussion 
of the materials to be used: stone, metal, wood, etc. 
With all the earthwork finished, bridges and heavy 
masonry work completed, the next subject is the 
permanent way of the line, and the author gives a very 
clear and concise account of the several component 
parts, especially dealing with the rail, its different 
sections and methods of support, with a clear treatment 
of the gradual introduction of curvature on rails by 
means of transition curves. The planning of stations, 
with the various problems involved in the junctions 
and crossings of the tracks, is given fairly thoroughly, 
and a chapter is devoted to station buildings, including 
the buildings required for the rolling stock. 
The book is of a type which would be welcome in 
Great Britain, although of course a translation would 
be of little use. 


Our Bookshelf. 
Carl Riimkers Hamburger Sternverzeichnis 1845-0, ent- 
haltend 17724 Sternorter, abgeleitet aus den Beobach- 
tungen am Meridiankreis der Hamburger Sternwarte 
in den Jahren 1836 bis 1856. Herausgegeben von 
Dr. Richard Schorr. Pp. xiv+488. (Bergedorf : 
Verlag der Sternwarte, 1922.) n.p. 
Dr. RicHarRD ScHorR has rendered a great service to 
exact astronomy in making and publishing this re- 
reduction of the great Hamburg catalogue of Carl 
Riimker, containing 17,724 stars, mostly faint, observed 
with the Repsold Transit Circle (of 4 inches aperture) 
between 1836 and 1856. It is of interest to learn from 
the short biographical sketch of Riimker that he held” 
a commission in the British Mediterranean fleet from 
1812 to 1817, holding the post of instructor in naviga- 
tion. He then went to Paramatta Observatory, N.S.W., 
as director ; while there he made useful observations of 
Encke’s Comet at its first predicted return in 1822. 
He returned to Hamburg as director of the Observatory 
in 1833, remaining there till his health failed in 1857. 
The Transit Circle was quite a good one, and the early 
date of the stellar observations renders them of value 
for the determination of proper motion. 
« i pt 
