APRIL II, 1912] 
NATURE 
149 
has been abandoned—as it should have been long 
ago. As the earth’s atmosphere is a constant quantity, 
the crest of a wave in one part must be compensated 
by a trough in another. Solar action must thus have 
a double effect of opposite nature upon the atmo- 
sphere. High pressure in one region must be counter- 
balanced by low pressure elsewhere, and maximum 
rainfall in one region will coincide with minimum 
rainfall in another part of the globe. This is the 
explanation of the apparent inconsistent conclusions 
arrived at in earlier investigations of relationships 
between solar and terrestrial weather. There is now 
no room for doubt that the earth’s meteorological con- 
ditions vibrate in sympathetic response to solar 
eriods of about four, eleven, and thirty-five years. 
There may be other periods of oscillation, but in any 
case these three exist upon the sun and earth, and | 
can be traced in the records of many phenomena. 
The shortest wave has been established by the 
Lockyers for solar and terrestrial variations, and the 
longest, represented by Briickner’s cycle on the earth, 
was discovered by Dr. Lockyer to have its counter- 
part on the sun. 
It is. not surprising that other investigators have 
arrived at much the same conclusions independently. 
In a paper published in The American Journal of 
Science of December, 1894, on “Inversion of 
Temperature in the 26-8-day Solar Magnetic Period,” 
Prof. F. H. Bigelow showed that the northern low- 
pressure and the southern high-pressure belts of 
THE ETNEAN ERUPTION OF SEPTEMBER, 
IQIl. 
ROF. A. RICCO, director of the Observatory of 
Catania, has issued a preliminary report on the 
eruption of Etna which took place last September 
(Boll. Sismol. Soc. Ital., vol. xv., pp. 273-280). The 
eruption may be said to have begun on the preceding 
May 27, when a new vent appeared on the north- 
east flank of the central crater less than a hundred 
metres below the rim, from which there issued hot 
white smoke, but no solid matter. In August, 
rumblings were heard in the central crater and in the 
new vent, and, from both, smoke and lapilli were 
discharged. This continued until the night of Sep- 
tember g-10, when a series of very strong earth- 
quakes occurred, and a great radial fracture, eight 
kilometres in length, was formed, running in a 
N.N.E. direction from the new vent. Some of the 
earthquakes were felt as far as Mineo, 60 km. from 
the volcano. In the Observatory of Catania, 30 km. 
distant, the Vicentini microseismograph was almost 
continuously agitated from midnight to 6 a.m. on 
September 1o. The strongest shock occurred at 
2.14 a.m., and at the same moment a new vent was 
opened, about 4 km. from the central crater, from 
which smoke, ashes, lapilli, and stones were ejected. 
| Later in the day, three new vents were opened, and 
North America vary in latitude directly with what he | 
se 
described as “solar magnetic intensity.” 
in the paper to a period of about three years, but his 
curves (reproduced in The U.S. Monthly Weather 
Review of November, 1903) only relate to meteor- 
ology and magnetism, and not to solar activity, the 
connection between magnetism and prominences not 
being described by him, so far as we know, until 
1902. In the following year Prof. Bigelow published 
a paper on “Synchronism of the Variations of Solar 
Prominences with the Terrestrial Barometric Pres- | 
sures and the Temperatures,”’ and showed direct and 
indirect changes of both pressure and temperature. 
In an article in Nature of January 8, 1903, Dr. 
Lockyer gave full credit to Prof. Bigelow, and stated 
that the two investigations were in agreement as re- 
gards three main points, namely :—(1) close connec- 
tion between solar activity and barometric pressure ; 
(2) great extent of areas over which very similar 
pressure variations exist; (3) presence of two large 
areas over which the pressure variations are reciprocal 
to each other. 
Quite recently a paper has reached this country 
(Bulletin No. 1 of the Argentine Meteorological 
Office) in which Prof. Bigelow deals with ‘‘ The 
Synchronism between the Variations of Solar Pheno- 
mena and the Meteorological Elements in Argentina 
and the United States.”” It is not clear whether the 
Bulletin is intended to be a semi-popular statement of 
the position of the subject or a contribution to scien- 
tific literature, but the almost complete absence of 
reference to the work of others suggests the former 
conclusion. Anyone not familiar with the points of 
progress would be led to believe that Prof. Bigelow 
is personally responsible for practically all that is 
known of solar and terrestrial relationships. L’Etat, 
c’est moi, said Louis XIV. on one occasion, and this 
spirit prevails in the paper before us. The only refer- 
ence to South Kensington relates to photographs with | 
a spectroheliograph, and no mention whatever is made 
of the investigations of solar and terrestrial meteor- 
ology, which, as may be judged from the foregoing | 
account, form a substantial part of the work of the 
Solar Physics Observatory. 
R. A. Grecory. 
NO. 2215, VOL. 89] 
He referred | 
| two lower emitted small streams of lava. 
| in the same direction is a tract of land to the south- 
by the next day there were sixteen in action, of 
which two emitted lava. 
On September 12, the number of new vents was 
greatly increased. They seem to have followed the 
line of the great fracture. The highest group con- 
sisted of six vents in a N.N.E. line, from which a 
great quantity of fragmentary material had been 
ejected, but which on September 12 had become 
almost inactive. A little lower down, in the same 
direction, was a row of four vents; and, still farther, 
a line of six others, very active, which discharged 
incessantly great masses of smoke and large stones. 
Lower stili was a fourth group, of four vents, arranged 
in a line bending towards the N.E., of which the 
Continuing 
east of Monte Nero, much fissured, and containing 
a long string of about thirty vents, from the lowest 
| and largest of which issued an important stream of 
| lava. 
To the north-east of Monte Nero, there started 
another line of craters (the sixth), about a score in 
number, from the lowest of which issued a second 
and larger stream of lava. This stream tollowed 
| the course taken by the lava in 1646, and, travelling 
with great rapidity, crossed the Circumetnean railway 
on the evening of September 12. Between the two 
craters emitting lava was a seventh group of cones, 
throwing out incandescent matter. 
On September 15 and 16, great masses of smoke 
were still emitted from the central crater and the 
vent of May 27. The two upper groups of vents 
were almost spent, the third continued very active; 
the fifth group of thirty or more vents emitted dense 
smoke and incandescent materials; in four days they 
had piled up cones some tens of metres in height; 
from the lowest lava still issued. The sixth group 
was also surrounded by lofty cones, from the lowest 
of which lava continued to flow at the rate of three 
metres a second. 
The eruption ended tranquilly on September 23.’ 
On October 1 the vents were again examined, and 
several changes were noticed. Those of the third 
group were united in four large craters; the fourth 
group consisted of twenty-seven vents, the fifth of 
1 The date is given as the 13th inst., but this is clearly a printer's error. 
| On October 1 the eruption had been ended about a week. 
