Marcu II, 1915] 

whilst there was a slight excess of sunshine in the 
western districts. Excessive rains were recorded over 
the whole of the United Kingdom, the fall being 
heaviest over England, where the rains for the whole 
country were 196 per cent. of the average. In Ireland 
the rainfall was 152 per cent. of the average, and in 
Scotland 131 per cent. The greatest excess of rain 
occurred in the south-east of England, where the 
measurement, 17-19 in., was 248 per cent. of the 
normal, whilst in the east of England the record was 
228 per cent. of the normal, and in the midland 
counties 196 per cent. The rainy days were in excess 
of the average over the entire kingdom, the excess 
being generally greatest in the English districts. 
Symons’s Meteorological Magazine for February 
gives the rainfall for January last at representative 
stations over the United Kingdom. The total at 
Camden Square was 4-12 in., which is 2-29 in. more 
than the average, and is 225 per cent. of the normal. 
This is the highest percentage of the average at any 
station given in the table, which, however, is only a 
tentative representation. Naturally there are many 
stations given with a larger rainfall, but the normals 
at these were larger. The map giving the Thames 
Valley rainfall for January, which in such times of 
fiood as the present is of special interest, shows an 
area in the neighbourhood of Marlborough with a fall 
of more than 6 in., and fairly large areas are given 
with more than 5 in. The rainfall of 4-12 in. at 
Camden Square is said to be the greatest in January 
in the fifty-eight years’ record, with the exception of 
January, 1877, when 4-74 in. was measured. Com- 
bining the records at Camden Square for the three 
months November, 1914, to January, 1915, the total 
measurement is 13-98 in., which is 56 per cent. of the 
annual average fall, and is 224 per cent. of the normal 
for the period. The rainfall for January is said to 
have been above the average over practically the whole 
of the British Isles, the excess being greatest in the 
south of England. On the Pennines 8 in. or more 
fell generally. A copy of a photograph is given 
showing the flooding of Salisbury Cathedral on 
January 5 and 6. In the neighbourhood the rainfall 
measured 16-86 in. from October 13 to December 31, 
and of this 2-93 in. fell in the last seven days of 
December, whilst an additional 2-06 in. fell in the first 
three days of January. The current. number com- 
mences the fiftieth volume of the magazine. 
THERE is a general belief that the paintings of old 
masters owe their success in some measure to secret 
processes or lost arts. A paper on the scientific aspects 
of this question is contributed by Dr. Maximilian 
Toch to the Journal of the Franklin Institute for 
January. Among other conclusions, the author points 
out that the painters only used a limited number of 
colours (madder being one) the permanency of which 
was well established, and that they avoided mixing 
those which were known to undergo chemical com- 
bination in each others’ presence. As examples of 
scientific methods of detecting later day copies, some 
interesting examples are given. The use of zinc 
white instead of flake white, the presence of proto- 
plasmic remains in the wood cells, and the trans- 
NO. 2367, VOL. 95 | 
NATURE 

45 
parency of the bitumen in the shadows are particular 
proofs that a picture is not a genuine antique. As 
regards deterioration, the author alludes to the serious 
effect of smoke and modern gas fumes, and further 
points out that while either light or darkness may 
bleach a picture, some that have been kept in the 
dark may be restored by placing them in bright sun- 
light. Finally, Dr. Toch condemns the style of 
modern painting, which substitutes the collapsible tube 
or palette knife for the brush, on the ground that the 
flakes of colour thus attached to the canvas will crack 
off and become detached. If, therefore, this method 
was ever used three hundred years ago, no traces of it 
, would now be in existence. 
Dr. W. C. Sastne publishes an account of a recent 
lecture to the Franklin Institute on architectural 
acoustics in the Journal of the institute for January. 
The investigations referred largely to the lecture hall 
of Harvard University, in which an ordinary spoken 
word remained audible for about 5} seconds. At first 
they were applied to determine the absorption only 
of a note of the pitch of violin C, but they have now 
been extended for three octaves in either sense. By 
introducing more and more cushions into the room a 
curve was plotted connecting the quantity of absorb- 
ing material with the duration of the sound, and was 
proved to be very approximately a rectangular hyper- 
bola. Another curve shows that the absorption increases 
with the pitch. An interesting feature is the diagram 
showing the distribution of sound intensity in a room 
with a barrel-shaped ceiling, and though the curves 
look remarkably complicated, the author finds that 
it is easy to observe the maxima and points of zero 
intensity. In conclusion the author says: ‘* While 
these several factors, reverberation, interference, and 
echo in an auditorium at all complicated are them- 
selves complicated, nevertheless they are capable of an 
exact solution, or, at least of a solution as accurate 
as are the architect’s plans in actual construction. It 
is entirely possible to calculate in advance of con- 
struction whether or not an auditorium will be good, 
and, if not, to determine the factors contributing to 
“its poor acoustics and a method for their correction.” 
It is a pity that these results are not generally applied, 
so as to prevent public halls being built in such a way 
that echoes make them almost useless. 
M. Henry Le Cuarecier has contributed an article 
on explosives to La Nature of February 20. In the 
article the general phenomena of explosion and the 
methods of measuring the relative value of explosives 
are discussed, much space being devoted to the pheno- 
mena of gaseous explosions. The general questions of 
the heat developed on explosion, the influence of 
mechanical forces, of chemical stability, and other 
minor points are touched upon. In conclusion, it is 
pointed out that the manufacture and employment of 
explosives are very complex questions, and demand 
long study; that in time of war it is not wise to intro- 
duce new explosives or great variation in methods of 
manufacture. Inventors and the public are apt to 
look more particularly for the production of explosives 
of enormous power without giving consideration to 
