THE MEDITERRANEAN NATURALIST 
265 
or even earth andsj and, and the water from these 
banks is led in summer by ditches to the cultivated 
fields. For southern Russia — where rain supplies 
about half the necessary moisture — it is estimated 
that an acre of wheat would be irrigated by 6000 
cubic feet of the compressed snow. 
A remarkable grotto Nature tells us was recently 
discovered during some mining operations at 
Faverny. 
It is a subterranean gallery of about 1500 feet in 
length, and ends in a great chamber about 40 feet 
in diameter and six feet high. 
Scientific men have hazarded various conjectures 
as to the source of the waterourse by which this 
cavity seems to have been formed. 
We are in receipt of the fourth number of the 
Rassegna delle Scienze Geologiche in Italia, a pu- 
blication which all geologists should have in their 
libraries. Besides the numerous reviews of the 
geological literature of the early part of the pre- 
sent year it contains an account of the history and 
development of the Geological Society of Italy, bio- 
graphical illustrated sketches of the late Professor- 
F. Giordano, and Baron A. De Zigno, and an il- 
lustrated article on the Eruption of Etna by Dr. 
M. Baratta. 
The researches of many observers, at reported 
upon by Dr. Buchan show that the ocean currents 
cause the temperature of the west side of the 
Atlantic, at depths from 100 to 500 fathoms to be 
nearly 10° warmer than at the same depths on the 
east side. At 500 fathoms, however, the tempera- 
tures of both sides are equal, while at greater 
depths the east side is the warmer. North of the 
Wyvil Thomson ridge, which is between Shetland 
and Iceland, stationary temperature is reached at 
700 fathoms, below which the water remains at 
about 29, 5". In the Gulf of Mexico, the water 
grows cold down to 700 fathoms, below which it is 
always at about 25. 5*. The temperature of the 
Mediterranean at 200 fathoms is about 56°, and no 
change is found in going to the bottom, which in 
] laces reaches a depth of 1500 fathoms. 
Mt. Etna is 10,868 feet high, 90 miles in circum- 
ference at the base, and has on its slopes two 
cities and 63 villages, with a total population of 
300,000. About 80 eruptions have been recorded 
the first mentioned having occurred early in the 
7th century B. C. The most disastrous was that 
of February, 1169, which destroyed the city of 
Catania, killing 15,000 people. In 1537 the village 
of Nicolosi was destroyed and a steam of lava ran 
15 miles to the sea. In 1669 several towns were 
damaged, and a fissure nearly 12 miles long, 6 feet 
wide, and of unknown depth, appealed, and for 
six months gave forth a bright light and smoke, 
with a roar that could be heard for 30 miles. The 
lava covered an area of 40 square miles. In the 
eruption of 1886, lasting three weeks, cinders fell 
at Messina, 80 miles away. The abyss of the 
crater was found in 1877 to be 1000 feet deep and 
nearly three miles in circumference. In the latest 
eruption lava has been flowing slowly from five 
craters. 
It is rumoured that the attempt to construct a 
telescope which shall be capable of bringing Mars 
within four miles of our vision has not yet been 
abandoned. M. Camille Flammavion in an article 
on the subject thinks that something might be 
done with a very large instrument, if fixed on a 
peak — a much larger instrument than the Lick 
telescope, and placed at a much greater height 
than the Lick. 
Paris, he says, is not suitable as it too low lying 
for immense magnifying power would only magnify 
the undulations of the air until the image lost all 
definition. 
Unfortunately we are not told how to get the 
instrument. The 36 inch glass of the Lick telesco- 
pe took years to make, and was not finished before 
£ 11,000 had been spent on it. 
No power perhaps is absolutely impossible — at 
present. 
A lively correspondence on the subject of birds 
v. insects has been carried on during the last week 
in the Malta local papers. The enormous increase 
of insectiferous pests during the last few years has 
caused the agricultural industries to decline to an 
alarming extent and it is urged that the evil has 
now increased so much as to call for legislation. 
In the Maltese Islands there are no laws for the 
protection of birds, and the lower classes of the 
Maltese being keen sportsmen no opportunities are 
allowed to either the migratory or the indigenous 
species of increasing. 
The result is the balance of nature has been 
disturbed, insects are in evidence everywhere, the 
crops are ruined — and the community suffers. 
