634 
NAT ORE 
[ Oct. 29, 1885 
space left behind the mass in its very swift flight. The gas 
mixture is probably of oxygen and hydrogen, and it becomes 
detonant when the proportions are near those in which the gases 
form water. The oxygen may be supplied from the air; the 
hydrogen may come from the meteorite itself, which, having like 
porous bodies and fused metals, taken it up and condensed it in 
some region of space, sets it free again as it becomes very hot by 
friction of the air, and as an enormous difference of pressure 
arises between the front and the back part. But a portion (and 
perhaps the larger) of the detonating mixture may come from 
dissociation of the aqueous vapour in contact with the glowing 
and fused surface of the meteor. To the idea of an actual ex- 
plosion of the meteorite by internal energy, Signor Bombicci 
objects that the ball must be shattered to the finest dust, and that 
fragments would not be coated with a crust. Sometimes meteorite 
stones remain quite whole in spite of the detonation. Haidinger’s 
idea of the sound being due to air rushing into the vacuum behind 
the meteorite is thought improbable because the detonation takes 
place in very high layers of the atmosphere, where the air is 
much too rare ; moreover the movement of the meteorite until 
detonation is a quite steady one. The character of the noise, 
and its repetition at intervals, also the shattering of the mass 
into fragments forming a cone of dispersion towards the earth all 
agree, in the author’s opinion, with an explosion of gas behind 
the meteorite. Referring to another point, Signor Bombicci 
thinks that the earth has by virtue of its magnetism a selective 
action on cosmic masses ; hence the universal presence of iron 
in meteorites, 
Messrs. A. AND C. BLack will publish immediately a volume 
by Dr. Croll, F.R.S., entitled ‘Discussions on Climate and 
Cosmology,” and also a new edition of ‘‘ Climate and Time.” 
ACCORDING to the ¥ournal of Indian Art the Government 
of India has decided to combine the duties of the Archeological 
Survey and those hitherto performed by the curator of Ancient 
Monuments. For this purpose India, exclusive of the Madras 
and Bombay presidencies, has been partitioned into three 
divisions, one of which has been placed under the control of 
Major Keith, who superintended the construction of the mag- 
nificent Gwalior gate which H.H. Maharajah Scindia has pre- 
sented to the South Kensington Museum, and which will be a 
prominent ornament of next year’s exhibition. 
WE have received from Mr. Saville Kent, Superintendent 
and Inspector of Fisheries in Tasmania, a very encouraging 
report of operations for the year ending July 31, 1885. Much 
of the report is devoted to oyster fisheries, which Mr. Kent is 
endeavouring to develop on scientific principles. He has 
established hatcheries at various points, and a laboratory for 
experiments, and under his care the oyster ought to become an 
important industrial product in Tasmania. He also advises 
the encouragement of sponge fisheries. With regard to Sal- 
monidz, Mr. Kent concludes that no true salmon have yet been 
established in the lakes and rivers of Tasmania. The fish of 
large size which abound in the great lakes and other large 
sheets of water are really essentially the same as the Great Lake 
Trout or Salmo prox of Great Britain. 
IN the Report by the Board of Trade on their proceedings 
and business under the Weights and Measures Act for the past 
year, it is stated that the attention of the department has been 
called by the Corporation of Dublin to the necessity of pro- 
viding a legal standard measure for testing steam pressure-gauges. 
In reference thereto regret has been expressed that at present 
the Standards Department has no power to do this. The ques- 
tion appears to be whether a pressure-gauge is a ‘‘ measure” 
within the meaning of the Act. The testing apparatus proposed 
by the Corporation is a measurer of pressure applicable only for 
special use, and it belongs to a class of measuring instruments, 
as barometers, thermometers, &c., not directly provided for by 
the Act. In the report of last year an opinion was expressed 
that the time had now arrived when this country might, under 
proper conditions, join the International Convention on Metric 
Standards, and in September last Her Majesty’s Government 
made known to the Comité International des Poids et Mesures” 
at Paris that England was willing to join the Convention. This 
has now been done ; and the Comité accepts the reservations of 
Her Majesty’s Government as to the introduction of the metric 
system into this country, affirming that there is nothing in the 
articles of the Convention which implies any obligation on the 
part of a contracting State to attempt to modify the system of 
weights and measures legalised at the time in that State. The 
adhesion of England, therefore, is not to be regarded as any 
expression of opinion that the adoption of the metric system in 
this country would be desirable. A copy is attached to the 
Report of a Memorandum on Metric Standards intended for 
laboratory use ; and also a copy of a scale of errors to be per- 
mitted on ordinary metric standards used in testing manufac- 
turers’ weights. Metric weights from 20 kilograms to o*’oor 
gram. to be used for the purposes of science and manufacture, 
or for any lawful purpose not being for the purpose of trade, 
have been verified for the local authority of Birmingham. 
Mr. CLEMENT L. WRraGGE, of the Torrens Observatory, 
near Adelaide, late of Ben Nevis, has been instructed by the 
Queensland Government to ‘‘ visit and report as to the best 
means of establishing meteorological stations in Queensland, 
including the Cape York Peninsula and Torres Straits.” Mr. 
Wragge, who lately returned to Brisbane from Northern Queens- 
land, will commence his duties early this month, and proceeds 
shortly to Normanton in the Gulf of Carpentaria, 
THE Institution of Mechanical Engineers met at Coventry 
yesterday, when the following papers were read :—On the con- 
struction of modern cycles, by Mr. Robert Edward Phillips, of 
London; on the distribution of the wheel load in cycles, by Mr. 
J. Alfred Griffiths, of Coventry; description of a hydraulic 
buffer-stop for railways, by Mr. Alfred A. Langley, of Derby. 
THE aquarium at the Inventions Exhibition has lately received 
some valuable additions in the form of golden tench, American 
salmonidee, and Italian carp, notwithstanding the fact that the 
Exhibition will shortly close. It is to be hoped that the exhibits 
from the Buckland Museum collection will be allowed to remain 
in the aquarium, where they appear to far better advantage 
than in their previous /oca/e. 
THE Ichthyological Museum now in course of formation at* 
South Kensington has been lately enriched with further valuable 
specimens of fish, Amongst them are some prawns unique in 
size, measuring ¢we/ve inches long, which were presented by 
Mr. John S. Charles, of Lower Grosvenor Square. 
THE Scientific American, in a recent issue, describes the tan- 
gent galvanometer constructed at Cornell University, from the 
designs of Mr. Anthony, the Professor of Physics, to meet the 
want ofa standard instrument for the measurement of heavy 
currents, and for the direct calibration of the commercial instru- 
ments in use for measuring the currents employed im electric 
lighting, &c. For the measurement of heavy currents there are 
four circles, two 2 metres in diameter, and two 1'6 metres, 
mounted, according to Helmholtz’s plan, at distances apart equal 
to their radii, The conductors forming these circles are copper 
rods, three-fourths of an inch in diameter. The needle is sus- 
pended by a silk fibre in a mass of copper, which serves as an 
effectual damper, and makes it possible to take readings very 
rapidly, By a peculiar arrangement of mirrors and telescope 
the deflections are read directly in angular measure on a circle 
50 inches in diameter, to within three-tenths of a minute of are. 
The copper conductors are mounted on a brass framework accu- 
