1829. 
level rail road, a speed of five mile per hour 
would, upon the principle of the square, 
bring therail road and canal to an equality ; 
whereas from a series of experiments by Mr. 
Walker, recorded in the last volume of the 
Philosophical Transactions, it appears that 
the two modes of conveyance are equal con- 
siderably under four miles per hour, and 
gives the rail way the decided preference at 
all higher velocities. In the present state of 
our commerce and manufactures, the main 
result of Mr. Walker’s paper, viz. the great 
superiority of land over water carriage, is a 
matter of national interest. 
Belemnites.—An eminent French natu- 
ralist, M. Raspail, has lately announced to 
the Institute that after a careful study of 
250 belemnites, collected in the mountains 
of Provence, he has discovered that belem- 
nites are not the shells of animals, as geo- 
logists generally think, but that they are 
cutaneous appendages belonging to marine 
animals, allied to the echinodermata, but 
which are now extinct. 
Fire Arms.—A French artist, M. Burel, 
has proposed to fix a small mirror, 0:47 of 
an inch square, in the side near the mouth 
of the piece, so that the person using it shall 
see the reflection of his own eye. - In this 
way it is supposed that very exact aim may 
be taken; and the experiments made by va- 
tious officers and sportsmen seem to encou- 
rage the idea that this application may be 
useful. It is considered as most likely to 
prove serviceable when applied to war 
pistols. : 
Roman Antiquities. —At Sainte-Colombe- 
Vienne, department of the Rhone, some 
very perfect remains of Roman baths have 
been discovered, together with the mutilated 
remains of what must have been fine statues, 
Also a fine marble monument, consisting of 
edestal in grey marble, with 
ion, has been found at Bor- 
It belonged to a votive monument 
rected to Tutela, a mysterious goddess of 
_ the ancient city. The inscription, which is 
well preseryed, is useful to prove the second 
consulship of Julianus, in 224, which, 
though mentioned in the Capitoline 
marbles, has been doubted by some anti- 
quaries. The face, opposite to the inscrip- 
tion, is decorated with a crown of oak. 
_ Permanent Increase of Bulk in Cast 
Tron by successive Heatings.—In the course 
of some experiments on high temperatures, 
Mr. Pringep, assay master of the mint, at 
Benares, discovered the very remarkable 
fact, that cast-iron acquires a permanent 
increase of bulk by each successive heating. 
This point is determined by measuring the 
cubic extent of an iron retort, as ascer- 
tained by the weight of pure mercury which 
it contained at the temperature of 80°. The 
actual contents were as follows: before the 
first experiment, 9°13 ‘cubic inches; after 
the first fire, 9°64; after three fires, 10-16. 
But what is more remarkable still, the aug- 
mentation of the bulk of the retort exceeds 
M.M. New Serics.x—Vou. VIL. No. 41, 
Varieties, 
553 
the dilatation due to the temperature to 
which it was exposed. or as iron expands 
0-0105 by 180 of Fahrenheit, the increase 
of bulk upon ten cubic inches should 
0:105¥3==0-315 at 1800° of Fahrenheit, 
or even the melting heat of silver. Hence 
we may conclude that the dilatation of iron 
is not equable—a result formerly obtained 
by M. M. Dulong and Petit. 
Earthquakes in Holland.—Earthquakes 
have been very rare in Holland; only ten 
were on record previous to last year; but 
during 1827 as many as three occurred, one 
on the 23d of February; the second, March 
21; the third, December 3. 
Eruptions of Mount /Etna.—Thucydides 
preserved the memory of three great erup- 
tions.. Diodorus records another which took 
place in the first year of the 96th Olympiad. 
One hundred and twenty-two years B.C. 
the earth shook and vomited fire, even under 
the sea, and vessels perished near the coast 
of Sicily. In Casar’s time, a great eruption 
took place, perhaps two; another, in the 
44th year of our zra, in the 252d and 812th. 
Only two eruptions are recorded in the 
twelfth century, one in the thirteenth, two 
in the fourteenth, four in the fifteenth, and 
four in the sixteenth. During the last part 
of the fifteenth century and the first part of 
the sixteenth, a period of ninety years inter- 
vened without any. Twenty-two eruptions 
were recorded in the seventeenth century, 
thirty-two in the eighteenth, and in the 
few years that have elapsed of this present 
century, already eight. 
Astronomy.—We mentioned in a former 
number of this journal that by the co- 
operation of the most eminent astronomers 
throughout Europe, under the direction of 
the Royal Academy of Sciences of Berlin, a 
series of celestial maps were being prepared 
to be published at the expense of the 
Prussian government. Two years were 
allotted to the observers for the execution of 
their respective parts, which period was to 
expire in the course of the present year. 
Two maps and the accompanying catalogues, 
by M. M. Inghirami, of Florence, and Har- 
ding, of Gottingen, have been already deli- 
vered, and are now in the hands of the 
engraver. 
Plantation of Potatoe Buds.—A clergy- 
man in Germany made some experiments on 
this subject in 1826. Notwithstanding the 
great dryness of the weather, the produce 
much surpassed his expectation, since each 
sprout yielded from three to four pounds of 
potatoes, and some of the potatoes weighed 
nearly .a pound each. He remarks, that 
according to his experience, the early pota- 
toe, called Hernkartoffel, by Putzsche, is 
the most advantageous for this method of 
propagation. A single germ gave sometimes 
from six to seven pounds of potatoes. 
Instinct of Spiders. —A_ small spider 
(Lpeira Diadema, Latreill), had spread its 
net between two neighbouring trees, at the 
height of about nine feet. The three prin. 
4B 
