26 NATURE 
| Marcu 28, 1907 
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9) 
departments of instruction of the new institution shall 
provide specialised courses in mining and metallurgy, and 
that department. shall be called and known by the name 
of ‘The Royal School of Mines,’ and the governing body 
shall award the diploma of * Associate of the Royal School 
of Mines’ to any student who completes such courses to 
the satisfaction of the governing body.’’ The individuality 
and history of the school will thus be preserved, and will 
not be sacrificed in what the chairman called a jumble. 
In conclusion, Mr. McKenna expressed the hope that 
though, in joining a larger association, the school neces- 
sarily will sacrifice a certain amount of individuality as a 
governing body, nevertheless by retaining the name and 
the diploma it will be compensated for any respect in 
which it may suffer by the advantages which will accrue 
from the fuller and more complete equipment. The name 
and the fame of the Royal School of Mines must be kept 
bright as a star in the firmament of the new institution, 
which is to be a pioneer even to Germany in the work of 
scientific training. 
SOCIETIES AND ACADEMIES. 
Lonpon. 
Royal Society, December 13, 1906.—‘‘ An Examination 
of the Lighter Constituents of Air.”? By J. E. Coates. 
Communicated by Sir William Ramsay, F.R.S. 
About 73,000 litres of air were systematically fractionated 
in order to ascertain whether any constituent lighter than 
hydrogen (e.g. coronium) were present. <A_ preliminary 
concentration of the lighter portions was effected by collect- 
ing the gas which had passed repeatedly through an air- 
liquefying plant, precautions being taken to avoid contamin- 
ation of the gas with hydrogen. By fractionation of the 
liquefied gas, a light portion having a volume of about 
4700 c.c. was obtained, which was further fractionated by 
absorption in charcoal at about —205° C. The lightest 
fractions thus obtained were examined spectroscopically, 
but no lines were detected which could not be attributed 
to hydrogen, helium, and neon. The volume of hydrogen 
amounted to 0-778 c.c., while the total volume of neon 
and helium obtained was 46 c.c. Assuming that 60,000 
volumes of air contain one volume of mixed neon and 
helium, it appears that hydrogen is present in the air to 
the extent of one part in about a million and a half. 
This estimate has been subjected to a correction for the 
solubility of hydrogen in liquid air, an approximate correct- 
ing factor being obtained by performing the fractionations 
on a sample of air to which a known small quantity of 
hydrogen had been added. This is much smaHer than 
previous estimates; it seems probable that hydrogen is a 
variable constituent of the atmosphere. 
January 31.—‘A Recording Calorimeter for Ex- 
plosions.’’ By Prof. Bertram Hopkinson. Communicated 
by Prof. H. L. Callendar, F.R-S. 
This paper describes a’ method of recording the heat 
lost up to any instant after an explosion of coal-gas and 
air in a closed vessel. For this purpose the vessel, which 
was cylindrical, and about 1 foot in diameter and 1 foot 
long, was lined first with a wooden backing }-inch thick 
and then with a continuous length of copper strip }4-inch 
wide by 1/25-inch thick. The strip was wound helically 
on the cylindrical part of the vessel, and the two end- 
plates were covered with parallel pieces joined up at the 
ends so as to form an electrically continuous length. 
The method consists in recording the rise of resistance 
of the whole length of copper strip when the explosion 
takes place. The rise of resistance is proportional to the 
rise of mean temperature of the strip. Hence, knowing 
the heat capacity of the copper, the total heat that has 
passed into it at any instant can be obtained from the 
record, after making certain corrections for the heat which 
has passed from the copper into the backing and into 
those parts of the walls which are not protected by the 
copper. 
The record of resistance was obtained by passing a 
known current (about 8 amperes) through the strip, and 
recording the potential at the terminals of the strip by 
means of a reflecting galvanometer having a period of 
NO. 1952, VOL. 75] 
about 1/15th of a second. The galvanometer was placed 
in series with a constant source of E.M.F. of such magni- 
tude as to balance the E.M.F. at the terminals of the 
strip when cold; the galvanometer deflection was then 
proportional to the rise of E.M.F. between the terminals 
of the strip, and so to the rise of resistance. The galvano- 
meter mirror reflected an image of a fine hole illuminated 
by an are lamp on to a photographic film carried on a 
revolving drum. A photographic record of the pressure 
in the vessel was obtained at the same time on the same 
film. 
The mixture used consisted of one part of coal-gas and 
about seven parts of air at atmospheric pressure and 
temperature. It was fired by an electric spark at the 
centre of the vessel. To test the accuracy of the calori- 
meter, the heat which had passed into the walls at the 
end of one second from firing was calculated from the 
record, and was found to be 10,000 calories. The tempera- 
ture of the gas at that moment was found from the pressure 
record to be 545° C. Using Holborn and Austin’s values 
for the specific heats of the constituents up to that tempera- 
ture, the heat remaining in the gas was calculated to be 
3800 calories. The total heat accounted for by the calori- 
meter and pressure records is therefore 13,800 calories, and 
this should be equal to the heat of combustion of the coal- 
gas used. This was the case within 2 per cent. 
The calorimeter record shows that during about two- 
fifths of a second after firing the rate of heat loss to 
the walls at any moment is approximately inversely pro- 
portional to the square root of the time. That is, the law 
of heat loss is initially the same as that of a solid at 
uniform temperature the boundary of which is suddenly 
cooled. It is pointed out that the rate of cooling is con- 
ditioned mainly by the state of the surface layer of gas 
in contact with the walls; at first heat is drawn from 
that layer, and the loss of heat is very rapid, but when 
the surface layer has been cooled down it acts as heat 
insulation for the remainder, and further cooling is re- 
latively slow. 
Linnean Society, February 21.—Prof. W. A. Herdman, 
F.R.5., president, in the chair.—The Perey Sladen Trust 
Expedition to the Indian Ocean in 1905 under Mr. J. 
Stanley Gardiner. (1) Description of the expedition. 
(i.) Introduction ; (ii.) history and equipment of the expedi- 
tion; {ili.) résumé of the voyage and work. Part i., 
Colombo to Mauritius: J. Stanley Gardiner and C. Foster 
Cooper.—(2) Land nemerteans, with a note on the dis- 
tribution of the group: R. C. Punnett. A single land 
nemertean obtained by Mr. Stanley Gardiner in the 
Seychelles must be referred to a new species, and has 
accordingly been named Geonemertes arboricola. The 
specific name has reference to the peculiar habitat of the 
worm, which occurs, among other places, in the leaf-bases 
e the screw-pine, Pandanus hornei.—(3) Land Crustacea : 
. A. Borradaile. The collection contained thirty species, 
marae to eleven genera. None were new to science, 
and all had previously been reported from the Indian 
Ocean. The fauna revealed by the collection is richer than 
that of the Maldives and Laccadives, but otherwise closely 
resembles it.—(q4) Hymenoptera: P. Cameron. Thirty- 
two species of the group were obtained, ants being ex- 
cepted. Of these, seventeen are described as new, one, 
Tolbia scaevola, as the type of a new genus. Ten species 
were obtained from the Chagos, three being new; and 
twenty-three from the Seychelles, including Coetivy, 
eleven new, the fauna for this archipelago now consist- 
ing of twenty-four species. As regards the habits of the 
species, it is suggestive that so many of them belong to. 
genera (Evania, Ampulex, Sphex, Notogonia, &c.) of 
which many, if not most, of the species prey on Orthoptera. 
—(5) Dragon-flies: F. F. Laidlaw. The collection con- 
tains fourteen species, none of which are new. All were 
obtained in the Seychelles, and four in the Chagos as well. 
It is suggested that the species peculiar to the Seychelles 
are a fragment of an endemic fauna which is being dis- 
placed throughout the whole Indo-African region by an 
invading fauna from the north.—(6) Fourmis des Sey- 
chelles, Amirantes, Farquhar et Chagos, déterminées par 
H. A. Foret. Nous avons pour les divers groupes d’iles 
en question 8 espéces cosmopolites, 8 espéces malgaches, 
