SCIENCE ON THE CONTINENT. 
531 
ten thousand times more resistance to the electric fluid than the other 
portions of the rod itself, so that when such a conductor is struck it 
presents a resistance in proportion, and becomes dangerous to surrounding 
bodies. 
The following instructive experiments have been made in support of 
these deductions : — One end of a rod, representing a lightning-conductor, 
having been placed at explosive distance from the conductor of an 
electric machine in communication with a Leyden jar, the other end 
was plunged into water contained in a metallic vessel in communica- 
tion with the exterior of the jar and with the earth, the rod itself 
being isolated in order that one electric current should not neutralize 
the other without passing through the water. The machine having 
been set in action, the electricity, instead of traversing the water without 
flash or noise, presented itself on the surface in the form of a brilliant 
star, the rays of which stood out from the submerged conductor often to 
three times the length of the spark of the machine. “ In order,” says M. 
Perrot, “ to test the electric tension at various parts of the conducting- 
wire, and consequently the danger to surrounding objects from an ordinary 
lightning-conductor, I applied a metallic sphere, and found that it was 
struck at distances varying from a fourth to a third of the length of the 
spark from the machine.” 
It is impossible to overlook the practical importance of these experiments 
and deductions, which demand careful examination by electricians. 
The Sarbonne. — Some few weeks since the learned world was con- 
siderably interested, and some of its members rather scandalized, by the 
fact of a young lady being 'admitted to academical honours. The other 
day another curious incident occurred within those ancient walls, where 
the Admirable Crichton carried off so many laurels in competition with 
the most brilliant scholars of his day. A young man born deaf and dumb 
having been received as a bachelor in the literary section, the examination 
was conducted in writing, the proficiency of the candidate being thoroughly 
established. This gentleman is the second son of the Comtesse de Chas- 
tellux, daughter of the Duchess de Rantzan, and one of four brothers, 
three of whom are deaf and dumb. 
The Academy of Sciences has elected Admiral Fitzroy a corresponding 
member in the section of geography and navigation, in the place of the 
late Admiral Sir James Clark Ross. 
English Steam-Engines for the French Navy. — A considerable 
number of eminent engineers and other scientific men, French and English 
in Paris, were invited a week or two since to see a beautiful working model 
of a pair of screw engines now being manufactured for the French man- 
of-war Vienne, building at Toulon. These engines were ordered by the 
Emperor of Messrs. Jack & Co., of Liverpool, and of the same pattern 
as those supplied by that firm to many mercantile steamers, but not yet, 
as we believe, introduced into the British Navy. The two great objects in 
view in Messrs. Jack’s arrangement are direct action upon the screw shaft 
and economy of fuel. The cylinders are on the Woolf principle of high 
pressure and expansion combined. The chief peculiarity, however, is the 
arrangement of the condensers, which are on the principle known as 
VOL. II. — NO. VIII. 2 0 
