JANUARY 18, 1901.] 
year and spent three months trawling and 
dredging on the coast of Japan. In June she 
sailed for Alaska on commercial investigations 
of the Alaska salmon fisheries. 
The statistical canvasses have this year cov- 
ered New England, New York and Lake Erie, 
and in May the canvass of the Pacific coast 
was begun. The figures for New England show 
a moderate falling off in value of fishery pro- 
ducts since the last tabulation in 1889, and also 
in the amount of invested capital, the latter 
caused by the transfer of the menhaden industry 
to New York. The lobster fishery has the re- 
markable record of a diminution, since 1889, of 
over 50 per cent. in quantity and a coincident 
increase of over 50 per cent. in value. The 
total value of New England fisheries reaches 
over nine and one-half millions. Lake Erie and 
Lake Ontario come forward with a large in- 
crease in quantity and value, the whitefish, a 
species very extensively propagated by the 
Commission, sharing largely in this expansion. 
Over three and one-half million pounds of the 
much-abused carp were taken from the Amer- 
ican waters of the lake in 1899, with a value of 
over $50,000. Indeed, a glance at the figures 
for this species shows that the carp is certainly 
the most valuable fresh-water fish after the 
whitefish and its allies, the pike perch and the 
lake trout, and should afford food for thought 
to those who condemn the carp as an unmiti- 
gated evil. The Illinois Fisherman’s Associ- 
ation reports the catch in the Illinois river as 
greater in quantity than that of all other species 
combined, with a value of nearly $200,000. 
Carp have increased many fold in the Middle 
Atlantic States and the Middle West during the 
last decade, the quantity taken in Lake Erie, 
the Illinois river, and the Ohio river and its 
tributaries, during 1899, being nine times that 
of six years ago. 
The annual visit to the fur-seal rookeries on 
the Pribilofs shows the continued decline of 
the seal herd as a consequence of the continu- 
ance of pelagic sealing. The number of seals 
taken from the islands under government 
Supervision was 16,812, and the pelagic catch 
from the American herd some 34,000. 
M. C. MARsH. 
SCIENCE. 
109 
A Handbook of Photography in Colors. By 
THomAs BouaAs, ALEXANDER H. K. TAL- 
LENT and EpGAR SENIOR. Published by 
Marion and Co., London. American edition 
by E. & H. T. Anthony, New York and Chi- 
cago. 
The authors of this book have brought to- 
gether in compact form the very scattered lit- 
erature pertaining to color photography. Part 
I., by Mr. Bolas, contains a brief history of 
helichromy, from the early work of Seebeck, 
Herschel and others until the present day, cov- 
ering about the same ground as the new edition 
of Zenker’s ‘Lehrbuch der Photochromie.’ 
His account of Wiener’s work and suggestions 
regarding the possibility of getting a truly 
chromo-sensitive surface will be found of use by 
any who are engaged in the hitherto fruitless 
search of a substance which when exposed to 
colored light will assume permanently the color 
of the illuminating light. That such a surface 
is theoretically possible is clearly shown, and 
methods of realizing it in a crude way are 
given. 
The general principles of the various proc- 
esses are given, including those of Joly, Ives, 
Lippmann and others. Lippmann’s account of 
his interference process as delivered in English 
before the Royal Photographic Society is given 
verbatim. His picture of the formation of the 
thin laminze which produce the colors by the 
stationary light waves is interesting. It will 
be remembered that these stationary waves are 
produced by backing the sensitive film with 
mercury. ‘‘If you put no mercury,’’ says 
Lippmann, ‘‘each train of waves rushes 
through the plate and wipes off every record 
of its own form by reason of its veloclty ; you 
cannot expect a thing which moves with a ve- 
locity of 300,000 kilometers a second to give a 
photograph of itself. If you put a mercury 
mirror behind the plate, then the following 
phenomena occur: the light is reflected back 
on itself; the light rushes in with the velocity 
of light, and rushes out with the same velocity ; 
the entering and issuing waves interfere, and 
the effect of interference is that vibration takes 
place, but the effects of propagation are stop- 
ped, and instead of having propagated waves, 
we get stationary waves; that is, the waves 
