Jumyis, 1915] 

NATURE 
547 

hydrodynamical problem: on the wave produced. by 
the sudden depression of a small portion of the bottom 
of a sea of uniform depth. This they show to be 
nearly the same as a somewhat different problem in 
which a small part of the surface is subjected to a | 
short-lived impulsive pressure. The numerical calcu- 
lations are long and laborious, and a comparison of 
the results of the calculation with what was observed 
at Miyako lead to the following conclusions :—(r) 
There is good agreement between the calculated and 
observed time intervals from the beginning of the 
earthquake to the arrival at Mivako of the first wave 
crest; (2) there is a fair agreement between the calcu- 
lated and observed time intervals from the beginning 
of the earthquake to the arrival of the second wave 
crest; (3) calculation and observation agree in assign- 
ing the greatest crest to the second wave. The paper 
is published in the Bulletin of the Central Meteoro- 
logical Observatory of Japan, vol. ii., No. 3, 1915. 
Remains of the gigantic horned dinosaurs from the 
Upper Cretaceous formations of Alberta, western 
Canada, have been collected so assiduously during the 
last few years, both by Canadians and Americans, 
that it is now possible to realise how numerous and 
varied were these strange land-reptiles. While de- 
scribing a new genus, Eoceratops, which he thinks 
may be ancestral to many of the others, Mr. Laurence 
M. Lambe has just published a tabular synopsis of the 
group, defining the various forms that seem to be 
distinguishable (Canada, Geological Survey, Museum 
Bulletin, No. 12, Geological Series, No. 24). Some- 
times the great bony frill over the neck is continuous, 
sometimes it is pierced with vacuities; while the shape 
and size of the bony bosses round its rim are remark- 
ably varied. There seems to have been a tendency 
in the horned dinosaurs to produce a separate bony 
boss on each prominence of the upper part of the skull, 
and scarcely any two specimens are alike. The nasal 
horn-core proves to be especially complex, being formed 
of the tips of the two nasal bones fused with a pair of 
superposed bony bosses. In one of the newly dis- 
covered skulls this nasal horn-core is in the shape of a 
forwardly turned hook. Mr. Lambe’s paper is illus- 
trated by numerous drawings of important specimens 
in the Canadian Geological Survey collection at the 
Victoria Memorial Museum, Ottawa. 
Tue Department of Revenue and Agriculture of the 
Government of India has issued a memorandum on 
the meteorological conditions prevailing in the Indian 
monsoon region before the advance of the south-west 
monsoon of 1915, with an estimate of the probable dis- 
tribution of the monsoon rainfall in 1915. The 
memorandum has been drawn up by Dr. G. C. Simp- 
son. A clear statement is given of each factor sup- 
posed to have a controlling influence on the conditions. 
High pressure over South America during the period 
March to May is found to be favourable to the mon- 
soon; the conditions under this head are said to be 
distinctly unfavourable. Low pressure in Australia, 
Indian Ocean, and Africa in May is favourable to 
monsoon rainfallin India, while a deficiency in rainfall 
at Zanzibar and in the adjacent parts of East Africa 
also has a good effect ; the conditions in this region are 
NO. 2385, VOL. 95] 

said not to be sufficiently pronounced to exert any 
marked influence. The effect of an excess of snowfall 
; accumulation upon the monsoon rainfall of India as a 
whole is to diminish it in the early portion of the 
season; while no effect on the rainfall of August and 
September can be detected; it is estimated that the 
snowfall is not likely to exert a prejudicial effect on 
the monsoon, but the prolongation of the winter con- 
ditions may indicate the late arrival of the monsoon 
and unsteadiness during the first part of the season. 
The conclusion arrived at is that while the monsoon 
of 1915 may not be so good as that of r9r4, there are 
no indications of a serious deficiency in the total rain- 
fall. The Arabian Sea current is likely to be less 
active than the Bay current. 
IN a paper on the temperature coefficient of mag- 
netic permeability of irons within the working range, 
which appeared recently in the Journal of the Bureau 
of Standards, Mr. R. L. Stanford directed attention to 
the necessity of either working at a standard tempera- 
ture, or determining the temperature coefficient of the 
actual material under test if results accurate to within 
I per cent. are to be obtained. On testing a number 
of rings of cast-iron, wrought-iron, and low carbon 
steels of about 10 cm. diameter and radial depth o-5 
to 1 cm. at temperatures between. 3° C. and 88° C., 
he found that before consistent results could be ob- 
tained it was necessary artificially to ‘‘age’’ the speci- 
mens by heating and cooling them a number of times. 
This process generally necessitated the use of about 
I5 per cent. more magnetising force to produce the 
same induction—2000 to 16,000o—in the aged specimen. 
For such specimens he finds that the temperature 
coefficient of permeability may be as high as o-3 per 
cent. per degree, and that a neglect of the temperature 
effect may in a rise of 10° C. to 20° C. produce an 
error of 2 per cent. or more. 
In a paper published in the Journal of Physiology 
for May 12, on the simple character of the yellow 
sensation, Dr. F. W. Edridge-Green brings forward, 
in a collected form, various arguments which have 
been urged in favour of this sensation being simple 
in contradistinction to the theory of Young-Helmholtz, 
which asserts that it is a sensation compounded of 
simple red and green. The chief support of the latter 
statement is the fact that a spectral yellow can be 
exactly matched by a superposition of red and green. 
Dr. Edridge-Green urges, however, that “it is wrong 
to assume that the physiological sensations are simi- 
larly constituted.” In many of the experiments that 
have been made by other observers coloured papers 
have been employed instead of spectral colours. Even 
the most superficial experimentalist will now admit 
that this practice robs the results of definite scientific 
meaning. Dr. Edridge-Green has studiously kept to 
spectral colours, and his results deserve close atten- 
tion. Amongst many other results he adduces the 
following :—(1) If the eye be fatigued with pure yellow 
spectral light the spectrum will appear to have lost 
its yellow, but the terminal red of the spectrum will 
not be affected. (2) If the eye be fatigued with red 
light even by looking through a red glass held against 
a light for one second, the red in the spectrum will not 
