9 
were often attacked and injured by the mob and their instruments 
broken. 
The hydraulic railway, or ‘‘ Chemin de Fer Glissant,” which 
was inaugurated at the Paris Exhibition, and in which Sir Edward 
Watkin takes so great an interest, is an ideal mode of travelling 
as regards swiftness of motion; the sensation resembles that of 
travelling in a sledge over ice in perfect condition, and is, in fact, 
similar in method, the carriages being mounted cn sledge plates, 
between which and the rails a thin film of water is interposed. 
The propulsion of the train is effected by horizontal columns of 
water from hydrants placed at intervals along the lines. M. Barre 
claims for his invention that the speed of 140 miles an hour can be 
obtained! Sir F. Bramwell considers the experiment highly 
interesting, but his opinion, in which the majority of our leading 
engineers coincide, is that it will hardly answer for long distances 
or for heavy commercial traffic. When we remember, however, 
that sixty years ago George Stephenson was the only engineer in 
this country who believed in the ultimate triumph of the steam 
locomotive, we shall beware of asserting that any new invention or 
suggested improvement is an impossibility. 
One of the most important factors in the Naval warfare of the 
future, is to be, we are assured, the pneumatic dynamite gur, 
which was recently tested in the novel American torpedo craft. 
the Vesuvius. Captain Zalinski’s invention displayed in its trial 
performance a capacity of throwing projecti'es beyond even the 
. claims of the contract, which stipulated that 15 shots should be 
fired in 30 minutes, whereas the actual result was, that 15 shells, 
each eight feet in length, and 15 inches in diameter, and holding 
respectiully 200lbs. of explosives, were discharged in 16 minutes 11 
seconds. The pneumatic pressure used in throwing these shells 
was 750lbs., but the air reservoirs are capable of containing a 
volume of 2,000 lbs. The range is obtained by varying the pressure 
of air behind the projectile. Although many of these guns are 
ordered by the American government, the Vesuvius is, at present, 
the only vessel where they are mounted. She is a large torpedo 
boat of 246 feet in length, and 26 feet in breadth, and carries as 
her chief armament three of these Zalinski guns, fixed parellel 
with one another, at an angle of 16 degrees above the horizon. 
The guns are capable of throwing shells containing 100, 200, or 
600lbs. of explosives, and can thus fire a broadside of over 1,500 
Ibs. of dynamite per minute. With weapons of such deadly power, 
a few shells would suffice to wreck any vessel or tort which came 
within their range, and as the Vesuvius has a freeboard of only 
5 feet, she does not herself afford a prominent target to the enemy. 
In our own country, considerable advance has been made in the 
