May 14, 1914| 
ary 26, 1859; while, from 1893 to 1900, twenty- 
seven strong shocks were felt, six of them being 
of ruinous strength. 
Many of these earthquakes were closely con- 
nected as regards time with Etnean eruptions. 
The earthquake of 1805 occurred after, and that 
of 1859 during, a period of activity. The earth- 
quake of 1865 took place eighty-eight days after 
the conclusion of a violent eruption; and that of 
1911 twenty-two days after the close of the last 
eruption, which began on September 10 of that 
year and lasted for twenty-three days. The recent 
shock occurred about two years and eight months 
after the end of the same eruption. 
The same phenomena seem to characterise all 
the earthquakes of this district. The disturbed 
area is small, the intensity of the shock great in 
its central portion, and the isoseismal lines ex- 
tremely elongated in form. In some cases the 
axes of the isoseismal lines are directed towards 
the central crater; in others (as in the earthquake 
of 1911) in a perpendicular direction. The small 
depths of the foci, their situation within the 
Etnean boundary, the direction of the meizoseis- 
mal bands, and the close connection of many of 
the earthquakes with eruptions of Etna—all these 
phenomena point clearly to the volcanic origin of | 
the earthquakes, their immediate cause being 
probably local slips along radial and peripheral 
fissures. ! C. Davison. 
THE BACHELET LEVITATED RAILWAY. 
“THE daily Press, or rather a section of it, has 
been greatly excited during the past week 
by the exhibition of a model railway, the inven- 
tion of M. Emile Bachelet, in which a metal car- 
riage is levitated in the air above the rails in a 
model railway, and then flung forward with very 
great speed through a.series of solenoids. The 
reporters for the daily Press have discovered new 
and tremendous possibilities in a scientific prin- 
ciple entirely new to them, but which has been 
perfectly well known to every electrician and 
physicist for the last twenty-five years. 
The repulsion of a metal plate or ring by an 
electromagnet or coil carrying an alternating 
current was discovered independently by Dr. J. A. 
Fleming and by Prof. Elihu Thomson. In 1887 
Dr. Fleming invented and described in the Elec- 
trician of March 25, 1887, an alternating current 
galvanometer, in which a copper disk suspended 
in the interior of a coil carrying an alternating 
current was repelled and deflected. On June 10, 
1887, Prof. Elihu) Thomson published in the 
Electrician a lecture on novel phenomena of alter- , 
nating currents, in which he described the repul- 
sion of copper disks and rings by an alternating 
electromagnet. Prof. Thomson’s apparatus was 
exhibited at the Paris Exhibition in 1889, and the 
experiments shown by Prof. Fleming to the Royal 
Society of Arts in a lecture in May, 1890, and 
also at a Royal Society soirée in the same year, 
1 M. Baratta, I terremoti d'Italia, 1901, pp. 829-33; A. Ricco, Boll. Soc. 
Sis. Ital., vol. xvi., 1912, pp. 9-38. 
WO: 2324, VOL. 93] 
NATURE 
273 
as well as at a Friday evening discourse at the 
Royal Institution in March, 1891. 
Dr. Fleming expounded the whole matter with 
numerous striking illustrations. Heavy copper 
rings were made to float in the air, or were shot 
up into the air with great velocity. This repulsion 
is due to the repulsion between the currents in 
the magnet coil and the eddy curents set up by the 
alternating field in the plate or ring. 
The principle was applied by Prof. Elihu Thom- 
son in the invention of an alternating current 
electric motor, and it has been developed in the 
well-known compensated repulsion motor of 
Winter and Eichberg. It is also applied in several 
forms of rotating and recording electric meter. 
The phenomena known as “electromagnetic re- 
pulsion”’ are therefore perfectly familiar to elec- 
| trical engineers, and except in the ingenious 
application to the support of a model railway car- 
riage there is nothing new. Press reporters and 
_ others who have been astonished by the exhibi- 
tion of this force are merely learning afresh facts 
which were publicly exhibited and described by 
| Profs. Fleming and Elihu Thomson nearly a 
quarter of a century ago. Careful experiments 
and quantitative measurements will, however, be 
necessary before any valid opinion can be formed 
whether. the principle admits of economical appli- 
cation in the propulsion of real railway trains. 
Nevertheless M, Bachelet deserves credit for his 
highly ingenious application of this well-known 
principle of electromagnetic repulsion. 
NOTES. 
Lorp Lamineton, G.C.M.G., G.C.I.E., has con- 
sented to be president of the Research Defence 
Society, in succession to the late Sir David Gill, 
| ROC TBs, Kak S- 
On the recommendation of the council and of the 
' special committee on the Hayden award, the Academy 
| of Natural Sciences of Philadelphia has this year 
conferred the memorial gold medal on Dr. Henry 
| Fairfield Osborn, in recognition of his distinguished 
work in vertebrate palzontology. 
Ar the annual meeting of the Irish Forestry Society 
on April 23, it was stated by Prof. Campbell that the 
department hoped to secure 15,000 acres tor State 
forestry in Ireland. A grant had been obtained from 
the Development Commissioners of 31,430l., spread 
over fifty-two years, for a scheme of forestry in Cork, 
and the department is applying for a further grant of 
45,0001. It is thus evident that State forestry in 
Ireland has broken ground in earnest, and this makes 
it all the more remarkable that State forestry in 
England and Scotlarfd should still be waiting to start. 
THE sixtieth general mecting of the Institution of 
Mining Engineers will be held in London, on Thurs- 
day, June 4, in the rooms of the Geological 
Society, under the presidency of Sir William E. 
Garforth. The following papers will be read, or 
taken as read :—Sinking and equipment of Blackhall 
Colliery for the Horden Collieries, Ltd., J. J. Prest 
