126 
POPULAR SCIENCE REVIEW. 
Of these, a striking one is now before us, and it is rendered doubly 
interesting from its immediate connexion with the general progress of 
every branch of science. It is a photographic picture of twenty-two 
gentlemen, leading members of the British Association, who met in Man- 
chester last year, and who are artistically grouped (mostly seated), in the 
drawing-room of the President, Dr. William Fairbairn. 
Some of the gentlemen are personally known to us, and, judging from 
the speaking likenesses of these, we have no doubt that all are equally 
perfect. There is a total absence of all stiffness or awkwardness either in 
the attitudes of the individuals, or in the whole or any portion of the 
group. One or two appear to be speaking, the rest listening attentively, 
and, quite contrary to photographic precedents, all appear smiling and 
good humoured. What renders this still more extraordinary is, that each 
of the portraits was taken separately, and the picture afterwards compiled 
by the artist, Mr. Alfred Brothers, of Manchester. 
The copy before us is reduced from the original, and is 16 inches by 9 
in measurement. The original is 2 feet 9 inches by 1 foot 7J, and its 
production involved no less than 40 separate printings ! The gentlemen 
thus vividly portrayed are : — J. F. Bateman, Esq., C.E. ; Sir R. Mur- 
chison, F.R.S. ; C. C. Babbington, Esq. ; Rev. W. V. Harcourt ; Rev. 
Dr. T. R. Robinson ; R. B. Darbyshire, Esq. ; Sir David Brewster, K.H., 
F.R.S. ; Alderman Neild ; Professor Airy ; Lord Wrottesley, F.R.S., &c. ; 
General Sabine ; Joseph Heron, Esq. ; Professor Miller ; M. Curtis, Esq. 
(Mayor) ; Alderman Mackie ; Win, Newmarch, Esq. ; Professors Hop- 
kins, Sedgwick, Willis, Phillips, John Crawfurd, Esq., and the President, 
Dr. Fairbairn. 
The price of the picture is a guinea, which is about the value of any 
one of the portraits, for those who take an interest in the persons photo- 
graphed. The London publishers are Day and Son ; Manchester, A. 
Brothers. 
One of the most conspicuous and, at the same time, important results 
which has made itself apparent, in connection with the display of 
photographs in the International Exhibition, has reference to the degree 
of permanence attainable in these works of art, and to the dependence 
which may be placed upon the photographic system of record. It is an 
undoubted fact, that a large number of the pictures on view at the Exhibi- 
tion are becoming rapidly defaced, and are showing the most unequivocal 
signs of fading ; some of these which have suffered most have contracted 
a uniform yellow complexion ; others, at an earlier stage, are fading in 
patches, and present a kind of mottled aspect ; some few of the worst 
cases have, we understand, been altogether withdrawn by their owners 
from public inspection. These appearances are by no means limited to 
the works of one or two operators, nor to. the productions of England 
alone ; for the same indications of fading are apparent in the beautiful 
specimens of photography distributed throughout many of the foreign 
courts. Numerous instances are observable in which, among several im- 
pressions mounted together in the same frame, and subject therefore to the 
