








ae So ‘ah, > 
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_. FEBRUARY-10, 1923] 
— 

_eaegioes of sexual Palolo in the surface waters, 
ic a thick macaroni soup, is a striking phenomenon 
iG enough, but it is one greatly enhanced by other 
- eunicids, other worms, many crustaceans, and other 
- animals all breeding in the same days of lowest 
tides, when the reefs are subjected to the greatest 
‘amounts of heat and light; indeed, similar sexual 
correlations with solar and lunar phenomena have 
now been suggested in nearly every group of animals. 
THe E?TEsIENS IN THE MEDITERRANEAN.—An 
article is given in the U.S. Monthly Weather Review 
- for August 1922, by Mr. J. S. Paraskévopoulos, of 
the National Observatory, Athens, on the etesiens, 
_ the characteristic north winds which blow during 
_ the summer in the region of the eastern Mediterranean. 
_ The marked regularity of these winds was observed 
_ by the ancient Greeks and the name signifies ‘“‘ winds 
blowing periodically every year.’’ The author has 
_ tabulated the data for several Greek meteorological 
_ stations, and for a period extending over 15 years, 
Ig00-14; the observations are made three times 
daily, at 8 a.m., 2 p.m., and g p.m., while for Athens 
the observations are continuous from self-recording 
instruments. The etesiens blow generally from the 
second 1o-day period of May until the middle of 
_ October, with two periods of maximum. During 
une the winds are interrupted ; in July and especially 
in August they are much more steady and frequent. 
_ In Athens before the middle of July the etesiens 
blow during the morning and are replaced in the 
_ afternoon by the sea breeze. The principal features 
_ of these winds have been known since the time of 
Aristotle. The anemometric data at Athens show 
that the velocity of the etesiens undergoes a very 
distinct diurnal oscillation; the speed during the 
daytime varies from 11 to 27 miles per hour, and it 
_ seldom reaches 45 miles per hour. Information is 
given as to their origin, with respect to the dis- 
tribution of atmospheric pressure, temperature, and 
humidity. As they contribute largely to the dryness 
$ e joe soil, they raise by their motion great quantities 
of dust. 
= 
Tue HumsBotpt CurRENT.— Variations in the 
temperature of the Humboldt current have been 
noted for many years and were recently examined 
by Mr. R. C. Murphy, who contributes an article 
to the Geographical Review for January on the 
oceanography of the Peruvian littoral. The uniform 
temperature conditions of this current are carried 
southwards from Peru at least so far as Valparaiso. 
Throughout this extent the lowest surface tempera- 
tures are in the inshore waters and are due to the 
te of bottom water which is the feature of 
is current. The steeper the coastal slope, the 
abe is the reduction of inshore temperatures. 
rregular variations in temperatures, which occur 
locally throughout the year, have been generally 
attributed to a shifting in the course of the current. 
Mr. Murphy believes that the cause is to be found 
in the northerly winds which accompany these 
abnormal sea temperatures. These winds drive 
warmer waters inshore and temporarily check the 
upwelling. More prominent is the current known 
on the Peruvian coast as El Nifio. This counter- 
q current of tropical water is felt seasonally north 
of about lat. 8° 13’ S. Mr. Murphy demolishes the 
theory that El Nijio is due to the waters of the River 
Guayas and holds that it can be correlated with 
changes in barometric pressure when the sun is south 
of the equator. The paper ends with some interesting 
correlations between the temperature variations of 
the Humboldt current, the distribution of plankton, 
and the valuable guano birds of the Pisco Bay 
NO. 2780, VOL. 111 | 
: b 
— le a 
NATURE 
bah 
region. The invasion of warm water destroys 
enormous quantities of plankton. The result is that 
the birds either migrate or have to face a loss of food 
supply. The latter course leads to a lowering of vitality 
and considerable reduction in numbers as the out- 
come of certain prevalent diseases which attack the 
weakened birds. 

EARTHQUAKES OF THE EAST INDIAN ARCHIPELAGO. 
—In a recent important memoir (Konin. Magnet. en 
Meteorol. Observ. te Batavia, Verhandelingen No. 7, 
1921) Dr. S. W. Visser has investigated the distribu- 
tion of earthquakes in the East Indian Archipelago 
from 1909 to 1919. The positions of the epicentres 
were determined from seismograms at the observa- 
tories of Batavia, Malabar, Manila, Sydney (River- 
view),-and Zikawei. Earthquakes strong enough to 
be registered at two or more of these observatories 
(160 near Western Java and 120 in other parts of the 
Archipelago) are confined as a rule to four principal 
regions—the Indian Ocean off southern Sumatra and 
western Java, the Celebes Sea and the Pacific Ocean 
south of Mindanao, the southern and eastern borders 
of the Banda Sea, and the mountain ranges of New 
Guinea. With the exception of the last region, the 
seismic zones of the Archipelago coincide with the 
steeply sloping sides of oceanic troughs in the close 
neighbourhood of the islands. The bottoms of the 
Indian and Pacific oceans far from land are probably 
nearly or quite aseismic. In a second memoir (Ver- 
handelingen No. 9, 1922) Dr. Visser studies the earth- 
quakes with an inland origin in Sumatra and Java 
only, the materials for the other islands being in- 
sufficient. They are few in number. For example, 
during the thirteen years 1909-1921, 13 earthquakes 
out of 859 in Sumatra, and 6 out of 748 in Java, had 
an inland origin. The distribution of inland earth- 
quakes in Sumatra is simple and regular. Most of the 
epicentral areas coincide with a long fracture which 
has given rise to an important series of longitudinal 
valleys in the Barisan mountain ranges. In yava the 
distribution is less regular. Violent earthquakes have 
occurred on the slopes of some volcanoes (for example, 
Mount Gede and Mount Tjerimai). They were, how- 
ever, of tectonic origin, the proximity of volcanoes 
being only a coincidence or due to their connexion 
with the same zones of weakness. At the times of 
severe earthquakes the activity of the volcanoes was 
either slight or altogether absent. 
Trouton’s Law.—When in 1884, in volume 18 of 
the Phil. Mag., Trouton showed that for a number 
of liquids the molecular heat of evaporation at the 
normal boiling-point was 20 times the absolute 
temperature at that point, the data by means of 
which the law could be tested were scarce and the 
accuracy of the values available not great. Additional 
and more trustworthy data were provided by 
Louguinine in 1896-1902 and the law shown to hold 
to within ro per cent. for groups of liquids of similar 
constitution, but to be sometimes 50 per cent. in 
error when, for example, alcohols were compared with 
organic acids. Further work has disclosed many 
exceptions and attempts have been made to find 
temperatures other than the normal boiling-points 
at which the comparison would give more consistent 
results. These have, however, been unsuccessful, 
and in the January issue of the Phil. Mag., Mr. 
S. B. Mali, of the University of Calcutta, states 
that there is no temperature at which the law holds, 
that it has no theoretical significance, and that it is 
an accident that it appears to hold for some substances 
at their normal boiling-points. This may be the 
correct view, but it is still remarkable that many 
liquids should fall into the accidental group. 
