_Juty 16, 1914] 
NATURE 
515 
A CONVENIENT method of determining the melting 
or solidifying range of temperature of a lava or 
similar substance, which on account of its want of 
homogeneity must be tested in bulk, is described by 
Messrs. K. Fuji and T. Mizoguchi in the March 
number of the Proceedings of the Tokyo Physical 
Society. The material to be tested is placed in the 
form of powder in an earthenware crucible of about 
50 c.c., and is heated in an electric resistance furnace, 
The temperature is measured by a_ standardised 
platinum platinum-rhodium couple, and the electrical 
conductivity by the current sent by an alternating 
electromotive force applied to two spherical platinum 
electrodes immersed in the molten material. The 
apparatus is standardised by the use of fused sodium 
chloride. According to the measurements made by 
the authors, the conductivity of molten lava may 
exceed o0’5 reciprocal ohms per centimetre cube, and 
may therefore influence the propagation of electric 
waves over that part of the earth’s surface beneath 
which it is present. 
In the July number of Science Progress the editorial 
article entitled ‘‘ Irrationalism”’ is a strong condemna- 
tion of the position taken up by the anti-vivisectionist. 
‘“Trrationalism,” it is truly urged, ‘‘is generally the 
enemy of humanity. In the form of crankism it 
clings shrieking to the hands of science just when 
she is engaged upon her most difficult but beneficent 
labours, and, in the form of political party, it paralyses 
the efforts of the wisest legislators.’’ The age of the 
earth is discussed by Prof. J. Joly, whilst Mr. H. S. 
Shelton, dealing with the same subject, brings for- 
ward arguments, with which probably most chemists 
will agree, to show that sea-sait data are unsatisfac- 
tory as a basis of calculation of geologic time. Mr. 
Arthur Holmes considers the terrestrial distribution 
of radium, which bears upon the same problem. 
Articles of general interest are contributed by Dr. 
J. J. Jenkins on scientific research and the sea- 
fisheries, by Mr. W. R. G. Atkins on some recent work 
on plant oxidases, and by Mr. R. Steele on photo- 
graphic and mechanical processes used in the repro- 
duction of illustrations. 
Tue fourth article on the Ford motor-car works in 
the Engineering Magazine for July describes the 
methods adopted for assembling motors and their com- 
ponents. It is common practice in these works to 
place the most suitable component on elevated ways 
or rails, and to carry it past successive stationary 
sources of component supply, and past successive 
groups of workmen who fix the various components 
to the principal component, until the assembly is com- 
pleted and ready to leave the assembling line. <A 
slow-moving chain is used in certain cases to drive 
the assembly in progress along the rails. The follow- 
ing figures will illustrate the saving in time effected : 
Motor assembling on separate benches gave, in Octo- 
ber, 1913, 1100 men working 9 hours to assemble 1000 
motors. On_ full-length motor-assembling lines, in 
May, 1914, 472 men working 8 hours assembled 1000 
motors. It will be understood that elaborate systems 
of making all parts to gauge and of rigid inspection 
WOn 2333, VOL. 93] 
of the finished components contribute largely to these 
results. 
AMONG the papers read at the Paris meeting of the 
Institution of Mechanical Engineers last week is one 
on signalling on railway trains in motion, contri- 
buted by the engineers of six of the French railways. 
On the Nord, a fixed ramp is set in the centre of the 
track parallel to the rails, and at a distance from the 
signal varying from the foot of the signal to 200 
metres. The oak beam forming the ramp carries a 
cover-plate of brass; a stout square piece of copper 
is riveted to the plate and is connected to the wire 
from the battery. Cushions of tarred felt are placed 
between the ramp and the sleepers so as to reduce 
vibrations due to trains passing. The locomotives 
carry an electro-automatic whistle, the steam or com- 
pressed-air valve of which is operated by a strong 
spring and a Hughes electromagnet. A brush on the 
locomotive formed of a series of small brooms of 
hard elastic copper, wire connects the electromagnet 
through the ramp to the battery; the other wire goes 
to earth through the wheels and rails. The signal 
vane is provided with a switch which controls the 
position of the signal vane as well as releases the 
whistle. All the installations described in the paper 
must be regarded as being in the experimental stage. 
WE have received a copy of ‘‘The Leather Trades 
Year Book,” the official publication of the United 
Tanners’ Federations of Great Britain and Ireland. 
The year-book is published at 3s., and can be ob- 
tained from the hon. editors, 176 Tower Bridge Road, 
London, S.E. It contains a large number of statis- 
tical data for the last five years of hides, tanning 
materials, and leather-made goods, and a series of 
illustrated articles dealing with the science and prac- 
tice of the leather industry. 
AMONG recent additions to the ‘‘ Cambridge Manuals 
of Science and Literature,” published by the Cam- 
bridge University Press at is. net each, the following 
deserve mention. One by Dr. R. A. Sampson, Astro- 
nomer Royal for Scotland, has the title, ‘‘The Sun,’ 
and provides in its 141 pages a brief statement of the 
present position of fact and theory relating to the sun. 
The second is by Mr. T. C. Cantrill, and deals with 
coal mining. He outlines the evolution of the in- 
dustry from its primitive beginnings, and indicates 
some of the far-reaching effects it has had on domes- 
tic and mechanical affairs. The third book, ‘The 
Making of Leather,” is by Mr. H. R. Procter, who 
gives a sketch of the methods and some discussion of 
what is a very ancient industry, involving in its ex- 
planation some difficult branches of human knowledge. 
OUR ASTRONOMICAL COLUMN. 
Comet 1914c (NEujmIN).—Prof. H. Kobold contri- 
butes to a supplement to Astronomische Nachrichten 
(No. 4748) the elements and ephemeris of the comet 
most recently discovered, namely, comet 1914c (Neuj- 
min). The observations of July 1, 2, and 3 were 
utilised and a parabolic system of elements was com- 
puted. The elements are as follows : — 
