NOVEMBER 22, 1906| 
by drainage, and pointed out that we were thus destroying 
a possible source of fuel supplies when our coal should be 
exhausted. 
Tue Channel tunnel project forms the subject of an 
article in the Engineer (vol. cii., No. 2654). Particulars 
are given of what has been accomplished, from an engineer- 
ing and scientific point of view, upon the other side of 
the Channel towards the solution of the great international 
problem. 
At the Institution of Civil Engineers on November 13 
a paper was read on single-phase electric traction, by 
Mr. C. F, Jenkin. A paper on electric traction on rail- 
ways, by Messrs. Mordey and Jenkin, was read before 
the institution in 1902. The object of the present paper 
was first to bring the previous account of the different 
systems up to date, and to show how far the conclusions 
then arrived at have to be modified in’ the light of recent 
experience, and then to describe the equipment required 
for single-phase working and to discuss the different 
problems which arise in connection with it. Little advance 
has been made in continuous-current working. The 
voltages have risen a little, and in a few cases pressures 
of 1000 and 3000 volts are in use. The principal advances 
in three-phase working have been the completion of the 
Zossen experiments, the opening of the Valtellina line, 
and the adoption of three-phase working for the Simplon 
Tunnel. Experience has confirmed Messrs. Mordey and 
Jenkin’s conclusion that the single-phase is the only system 
which can satisfy all the requirements of a general system. 
AccorpING to the official statistics published in the 
Mines and Quarries General Report (part iii., 1906) the 
output of coal in Great Britain in 1905 was the highest 
hitherto recorded, being as much as 236,128,936 tons. Of 
this total, 47,476,707 tons were exported, and 19,255,555 
tons were used in the manufacture of pig-iron. The home 
consumption was 3-91 tons per head of population. 
Statistics relating to the manufacture of coke and briquettes 
were collected for the first time, the production of coke in 
1905 having been 18,037,985 tons, and that of briquettes 
1,219,586 tons. There were 31,060 coke ovens in operation. 
Of these, 25,514 were of the beehive type; and there were 
2233 Coppée ovens, 726 Simon-Carvés ovens, 503 Otto- 
Hilgenstock ovens, 470 Semet-Solvay ovens, 72 Koppers 
ovens, 52 Bauer ovens, and 1490 other kinds. The pro- 
duction of iron ore was 14,590,703 tons, which yielded 
nearly one-half of the total quantity of pig-iron (9,608,086 
tons) made in the country. Copper, lead, silver, and tin 
show an increase on the figures of 1904, both in the 
amount and in the value of the metal obtained. 
A SIMPLIFIED method of transforming readings of the 
Fahrenheit thermometer into centigrade values and vice 
versd is given by Dr. Hellmann in No. 38 of the Natur- 
wissenschaftliche Rundschau. The ordinary formule, for 
example C=5/9(F—32), are not adapted for rapid calcu- 
lation. The modified formule 
C=(4-% . x5 -4 - x30) (F-32), and F=(2-34)C +32, 
on the other hand, containing decimal fractions, lend them- 
selves much more readily to the purpose. To transform, 
for example, 110° F., we have 110—32=78, and the centi- 
grade value becomes 39+3-9+0-4=43°-3- 
A REVISION, of the atomic weight of bromine made by 
Mr. Gregory P. Baxter in the chemical laboratory of 
Harvard College is published in the Proceedings of the 
American Academy of Arts and Sciences (vol. xlii., No. 11). 
Considerable uncertainty exists as to the purity of the 
NO. 1934, VOL. 75] 
NATURE 
| easy to ensure the absence of occluded gas. 
85 
materials employed in several of the earlier determin- 
ations, owing principally to the fact that while it is easy 
to eliminate metallic impurities from silver, it is not so 
Two different 
adopted in the determinations: in one, 
highly purified silver was converted into silver bromide; in 
the other, the ratio of silver bromide to silver chloride was 
determined by acting on the former with purified chlorine. 
As many different methods of purification as possible were 
employed for the materials used. Eighteen determinations 
by the first method gave a value of the atomic weight 
varying from 79-950 to 79-955, silver being taken as 107-930; 
thirteen determinations by the second method ranged from 
79-951 to 79-955. 
methods were 
The average of both series was 79:953- 
A VOLUME of essays, or rather lectures, by the late 
Lieut.-General A. Lane-Fox Pitt-Rivers, edited by Mr. 
J. L. Myres, will be issued immediately by the Oxford 
University Press. Mr. Henry Balfour, the curator of the 
Pitt-Rivers Museum, written an introduction to the 
volume, which is entitled ‘‘ The Evolution of Culture.”’ 
Tue eleventh volume of the complete works of Christiaan 
Huygens, which are being published from time to time 
by the Société Hollandaise des Sciences, is in course of 
preparation, and will, it is expected, be ready in about a 
year. The tenth volume -of the works was reviewed in our 
issue for August 17, 1905 (vol. Ixxii., p. 362). Meanwhile, 
an extract from the eleventh volume has been issued 
separately under the title ‘‘ Travaux divers de Jeunesse, 
1645-1646 ’’; it is edited by M. D. J. Korteweg, and. pub- 
lished by M. Niihoff, of the Hague. Several papers written 
by Huygens in 1645 and 1646—that is to say, in his seven- 
teenth and eighteenth years included in this pre- 
liminary publication. 
has 
are 
Messrs. WILLIAMS AND NorGate have sent us a pro- 
spectus of ‘‘ The Paintings of Antiquity,’’ edited by Herr 
Paul Herrmann, and published by Herr F. Bruckmann, of 
Munich. The work is to be published in sixty parts, and 
will contain about 600 plates, of which twelve to fifteen 
will be coloured. Six parts will be published annually. 
The nucleus of the collection of pictures is formed by re- 
productions of wall paintings removed from their original 
positions in houses at Pompeii, Herculaneum, and Stabiz, 
and taken to the Museo Nazionale at Naples. A limited 
selection of mosaics will be included. Whatever paintings 
have been preserved of the ancient Greek and pre-Hellenic 
periods will be comprised in the collection; and the work 
will also include the most important of the mummy por- 
traits from the Fajam. 
OUR ASTRONOMICAL COLUMN. 
AnotHeR New Comer (1906h).—A telegram from the 
Kiel Centralstelle announces the discovery of a comet on 
November 14 by Mr. Joel Metcalf, of Taunton (Mass.). 
Its position on that date at 1oh. o-4m. (Taunton M.T.) 
was R.A.=4h. 4-6m., dec.=2° 16’ S., and the apparent 
direction of its motion is given as south-west. This posi- 
tion is about half-way between 35 and & Eridani, and 
crosses our meridian shortly after midnight. The comet’s 
magnitude is given as 12-0. 
A second telegram states that this object was observed 
by Mr. Hammond at Washington on November 16, its 
position at 11h. 38m. (Washington M.T.) being 
R.A.=4h. qm. 11-4s., dec.=2° 46’ 55” S., 
and its magnitude 11-0. 
Comet 1906g.—From observations made on November 
10, 11, and 12, Herr M. Ebell has calculated a set of 
elements and an ephemeris for comet 1906g, the discovery 
of which was announced in these columns last week. The 
elements show that this comet passed through perihelion 
on November 7. 
