406 
NATURE 
[AuGus1 21, 1902 
fall on the boat, They were followed by small pellets, which 
rattled on the deck like a shower of peas. In a minute or two 
fine grey ash, moist and clinging together in small globules, 
poured down upon us. After that for some time there was a 
rain of dry grey ashes. But the cloud had lost most of its 
solid matter, and as it shot forwards over our heads it left us in 
a stratum of clear pure air. When the fine ash began to fall 
there was a smell of sulphurous acid, but not very marked. 
There was no rain. 
The volume of steam discharged must have been enormous, 
for the tongue-shaped cloud broadening as it passed southwards 
covered the whole sky except a thin rim on the extreme horizon, 
Dust fell on Fort de France and the whole south-end of Mar- 
tinique. The display of lightning was magnificent. It threaded 
the cloud in every direction in irregular branching lines. At 
the same time there was a continuous low rumble overhead. 
What happened on Mont Pelée after this discharge cannot be 
definitely ascertained. For some hours afterwards there were 
brilliant lightnings and loud noises which we took for thunder. 
That night there was a heavy thunderstorm over the north-end 
of Martinique, and much of the lightning was atmospheric, 
but probably the eruption had something to do with it, and the 
noises may have been in part of volcanic origin. 
Characteristics of the Eruptions. 
There can be no doubt that the eruption we witnessed was a 
counterpart of that which destroyed St. Pierre. The mechanism 
of these discharges is obscure, and many interesting problems 
are involved. But we are convinced that the glowing avalanche 
consisted of hot sand and gases—principally steam ; and when 
we passed the hill in R.M.S. Wear a few days later, we had, 
by the kindness of the captain, an excellent opportunity of 
making a close examination of the shore from the bridge of the 
steamboat. The south-west side of the hill along the course of 
the Riviére Seche was covered with a thin coating of freshly 
fallen fine grey ashes, which appeared to be thickest in the 
stream valleys. The water of the rivers Howing down this part 
of the hill was steaming hot. This was undoubtedly the 
material emitted from the crater on the night of the eruption. 
There was no lava. We saw no explosions of combustible 
gases, and nothing likea sheet of flame. We were agreed that 
the scintillations in the cloud were ordinary lightnings which 
shot from one part of its mass to another, and partly also struck 
the sea beneath. 
The most peculiar feature of these eruptions is the avalanche 
of incandescent sand and the great black cloud which accom- 
panies it. The preliminary stages of the eruption, which may 
occupy a few days or only a few hours, consist of outbursts of 
steam, fine dust and stones, and the discharge of the crater 
lakes as torrents of water or of mud. In them there is nothing 
unusual, but as soon as the throat of the crater is thoroughly 
cleared, and the climax of the eruption is reached, a mass of 
incandescent lava rises and wells over the lip of the crater in 
the form of an avalanche of red-hot dust. It is a lava blown 
to pieces by the expansion of the gases it contains. It rushes 
down the slopes of the hill, carrying with it a terrific blast, 
which mows down everything in its path. The mixture of 
dust and gas behaves in many ways like a fluid. The exact 
chemical composition of these gases remains unsettled. They 
apparently consist principally of steam and sulphurous acid, 
There are many reasons which make it unlikely that they con- 
tain much oxygen, and they do not support respiration. 
THE PERSEID METEORIC SHOWER OF 1902. 
“THE display of Perseid meteors was fairly abundant this year, 
though somewhat marred, and only partially observed, in 
consequence of the unsettled weather which prevailed. In the 
west of England the first half of August proved an exceptionally 
cloudy period, and comparatively few observations could be 
secured. In the eastern counties atmospheric conditions appear 
to have been decidedly more favourable, for while at Bristol 
only meagre results could be gathered from skies wholly or 
partially veiled with clouds, observers in metropolitan suburbs 
reported clear weather and collected a plentiful harvest of 
meteor flights. At Hampstead Mr. G. M. Knight counted 
500 meteors during the first fortnight of August. Between 
August I and 5, 167 were recorded, and on August 10, from 
NO. 1712, VOL. 66] 
1th, 30m. to 15h. 15m., 239 were seen. The majority of them 
were Perseids of the usual swift, streak-leaving type, and there 
were minor showers in Cassiopeia, Andromeda, Cepheus and 
other regions. Mr. Knight has forwarded the writer some 
charts containing projections of his recorded paths, and the place 
of the Perseid radiant appeared to be indicated as under. The 
ephemeris positions given in the Monthly Notices, December, 
1901, p. 169, are also added for comparison :— 
1902. Radiant. JNe..08 Ephemeris. 
August 1-3 ... 37 + 55+ 12... 33°9 + 55°0 
Dt A525 GO: Bb are! 20a 97. ON Fi 5 5/0) 
mn IO ... 444+ 57 ..-:43 --. 44°93 + 5679 
The agreement is fairly good, though the places observed 
this year in the early part of August are somewhat east of the 
predicted centres. A certain allowance has, however, to be 
made for errors of observation. 
At Bristol the writer watched for the Perseids on parts of the 
nights of August 2, 6, 10, 12 and 14, but clouds prevented any- 
thing like a thorough investigation of the progress of the display. 
The Perseids were fairly numerous, and shot from the radiants 
given below, but very few meteors were seen on August 6 and 
14 owing to the clouds, so that the points of emanation on those 
nights were merely suspected :— 
1902. Radiant. Ephemeris. 
August 6 30 ae 57 38.9 + 56'0 
TO 25 45 ct 58a 44°3 + 569 
IZ) e-- 4 7 two 471 + 57°3 
TAs oes | SOMeGMST 50°0 + 577 
The year 1900 not having been a leap-year, the maximum 
was expected on either August II or 12. There was an un- 
usually bright exhibition of these meteors on August 11, 1898. 
It seems that the maximum intensity was well defined this 
year, for ‘‘a magnificent shower of Perseids” is reported to 
have been witnessed at Odessa on Tuesday night, August 12. 
The chief radiating point is said to have been at an altitude of 
45 or 50 inthe north-east firmament, The latter position cor- 
responds approximately with the normal place of the Perseid 
centre. But, unfortunately, the report mentions no details as to 
the number of meteors observed or the duration of the observa- 
tions, and it is impossible, therefore, to form any exact conclusion 
as to the character of the display witnessed. It will probably 
be found, however, when particulars come to hand, that it 
represented nothing more than a tolerably plentiful return of the 
stream. There are no other descriptions favouring the inference 
that a strikingly brilliant shower was witnessed. In and since 
1898 the Perseids appear to have been richer than usual, though 
it is extremely difficult to ascertain the relative strength of the 
shower from year to year owing to the variable conditions 
affecting the visibility of the meteors. W. F. DENNING. 
THE ZOOLOGICAL SOCIETY’S NEW 
APE-HOUSE. 
THE ordinary plan of keeping monkeys in zoological gardens 
is to house them in cages which, while closed in winter, 
can be opened to playing-places in the external air in summer, 
The objection to this course is that, though it gives the great 
advantage of fresh air, the monkeys emerging from a heated 
chamber into a cooler atmosphere are very liable to catch cold 
and suffer from pulmonary complaints. In the case of some of 
the hardier Quadrumana (such as the Tcheli monkey of Mant- 
churia and the Cape baboon), there can be no doubt that such 
animals will thrive best without artificial warmth of any kind 
beyond the protection of a dry roof, and may be kept in the 
open air all the year round. This plan, however, would hardly 
answer in the case of the anthropoid apes, which live in hot, 
moist climates and are accustomed all their lives to a high and 
uniform temperature. In constructing the new ape-house for 
the special accommodation of these animals, the Zoological 
Society has adopted the plan, which has been tried with some 
success on the continent, of separating the animals entirely from 
the evils of a changeable climate by an air-tight glass screen 
through which only they can be seen by the public. The 
