NOVEMBER 29, 1906 | 
NATURE 
IOI 
thing of the personal history of those pioneers in 
technology who have been so largely instrumental in 
bringing one of our staple industries to its present 
pitch of development. T. E. TuHorre, 
AIDS TO PHOTOGRAPHY. 
(1) The Year-book of Photography for 1906-7. Edited 
by F. J. Mortimer. Pp. 618. (London: The Photo- 
graphic News, 1906.) Price 1s. paper, 1s. 6d. cloth. 
(2) The Photographic Picture Post-card. By E. J. 
Wall and H. Snowden Ward. Pp. 104. (London: 
Dawbarn and Ward, Ltd., 1906.) Price 1s. net. 
(3) Magnesium Light Photography. By E. J. 
Mortimer. Pp. 88. (London: Dawbarn and Ward, 
Ltd., 1906.) Price rs. net. 
(1) ‘tae present number is the forty-seventh issue 
of this hardy annual, and the amateur or pro- 
fessional photographer will not have much to complain 
about when he has entirely digested its contents. 
In its present form it is a mine of photographic in- 
formation, and contains data which are indispensable 
to every worker. Thus there are useful hints for 
negative making and finishing, complete and up-to- 
date directories of the photographic societies of the 
United Kingdom, a collection of useful recipes, 
formule, and reference tables of general use for every 
kind of work. 
In addition to these and many other data which are 
valuable to the working photographer, there is a 
series of very interesting and helpful articles. These 
have been written by such well-known men as Robert 
Demachy, Walter Benington, George E. Brown, E. J. 
Wall, and others, and are on those particular subjects 
which have brought their names in the front rank. 
Two full and very practical articles on bromide and 
gas-light printing are contributed by the editor, and 
these contain much that is new and useful to the 
practical worker. 
In fact, the volume should naturally find itself in 
the hands of every photographer, and is an indispen- 
sable book of reference. Sixteen full-page illustrations 
on art paper accompany the text, and an excellent 
index completes the volume. 
(2) In this book the authors describe the making 
of picture post-cards from the initial sizing of the 
card down to the finished article. The beginner 
should find no trouble in following the instructions 
laid out, for the authors have described the various 
manipulations in clear and concise language. 
Chapters are devoted also to photomechanical pro- 
cesses of producing a number of cards of one subject 
and to colouring post-cards, while part ii. of the book 
deals with such information as how to publish the 
cards, how to sell rights of reproduction, &c. Those 
who have a fancy for printing their negatives in this 
manner will gain some useful wrinkles by carefully 
reading this guide. 
(3) Mr. Mortimer describes another phase of camera 
work which is as useful to the amateur as the pro- 
fessional. Mr. Mortimer does not let the worker 
take much for granted, for in these pages he refers 
to nearly every kind of subject that may be met with, 
NO. 1935, VOL. 75 | 
. 
from a flower study in a studio to the stoke-hold of 
a warship. The value of the text is very much 
enhanced by some excellent illustrations indicating 
not only the relative positions of camera, subject, and 
flash-lamp, but the actual results produced in these 
circumstances. 
Beginners and others will do well to read this book, 
which embodies the results of one who has had a 
very wide and successful practical experience in this, 
branch of the subject. 
OUR BOOK SHELF. 
The Rusts of Australia; their Structure, Nature, and’ 
Classification. By D. McAlpine. Pp. vii+349; 
plates, 55. (Melbourne: R. S. Brain, Government 
Printer, 1906.) 
Tuts book is published by the Department of Agri- 
culture of Victoria, and represents the labour of 
many years on the part of the Government patho- 
logist (vegetable). The first part, up to p. 75, con- 
tains much useful matter, although, of course, only 
a summary of the work of others. The second part 
is also necessary and useful, but contains some serious. 
blemishes. 
The author records sixty-three new species, the: 
majority of which are more or less unsound, being 
simply forms of the same fungus growing on 
different hosts; and when, as on pp. 160, 165, the 
hosts have been incorrectly determined, the fungi 
have been given incorrect names. The author does 
not err alone in this matter, but the better botanists 
set their faces strongly against this practice of 
naming parasites according to their hosts. without 
any experimental inquiry as to whether the same 
fungus might not infest many hosts, as in fact they 
do in many cases, and can probably be caused to 
do in still more. The seventy-two rusts recorded in 
Cooke’s ‘‘ Handbook to the Fungus Flora _ of 
Australia ’’ are now increased to 161, but it is diffi- 
cult to say to what extent this merely represents 
records of previously known species on new hosts. 
In some cases the new species are supposed to be 
distinguished by minute differences in the shape and 
character of the spores. Yet on Plate xl., p. 320, 
are figures of abnormal spores of one species giving 
a greater range than that which in others makes, 
new species. A good instance of the confusion which 
arises from the system of naming is given on p. 169, 
where four names are inextricably entangled, and the 
author solves this difficulty by creating a name of 
his own, and so making matters worse for subse- 
quent investigators. 
The coloured plates are good, with the exception 
of Plate i., which is useless for fungal diagnosis. 
There are far too many photomicrographs; a few 
give verisimilitude to a paper and confirm the bona 
fides of the author, but good hand drawings are 
always better for reference if they can be relied on. 
On the whole, there can be no doubt that the book 
a useful one. A few typographical errors, such 
as Schelhammera for Schelhammeria, are unavoid- 
able in a work of this kind, but our author is mis- 
taken in supposing that the Kew index is an 
infallible guide in questions of synonymy and in the 
naming of species. It would have been better, both 
from the scientific and economic points of view, if 
the work on which the book is based had been more 
experimental and less taxonomic in character. Prob- 
ably the author felt that owing to the amount of 
ground to be covered only a general review of ii 
is 
