390 
POPULAE SCIENCE REVIEW. 
Petroleum in Canada. — It would appear from the recent statements in an 
American periodical, that Professor Silliman examined part of California in 
the summer, and found oil, equal in quality to the best in Pennsylvania, 
struggling to the surface of the earth, and running to waste for miles. In 
some places it has entirely prevented the progress of agricultural operations. 
The Mont Cenis Tunnel. — In a late number of the Revue Contemporaine 
some interesting details concerning the apparatus employed in boring through 
the Alps are given. The machine consists of a piston working horizontally 
in a cylinder, and carrying a chisel fixed upon it like a bayonet, which at 
each stroke dashes with violence against the rook to be pierced. Each time 
the chisel recoils it turns round in the hole, and as the latter is sunk deeper 
and deeper, the frame-shield, which carries not one, but nine perforators, 
advances in proportion. While the chisel is doing its work with extraor- 
dinary rapidity, a copper tube of small diameter keeps squirting water into 
the hole, by which means all the rubbish is washed out. Behind the shield 
there is a tender, which, by the aid of a pump set in motion by compressed 
air, feeds all these tubes with water. The noise caused by the simultaneous 
striking of aU the chisels against the rock is absolutely deafening, enhanced 
as it is by the echo of the tunnel. All at once the noise ceases, the shield 
recedes, and the tunnel is perceived riddled with holes varying in depth from 
eighty to ninety centimetres. These holes are now charged with cartridges, 
slow matches are inserted, and the workmen retire in haste. The explosion 
seems to shake the mountain to its foundation ; and when all is over the 
ground is covered with fragments of rock, and an advance equal to the depth 
of the holes has been obtained. 
What are Alloys ? — A curious paper, entitled “New Facts relating to Cast 
Iron and Steel,” appears in the Comptes Rendus, from the pen of M. Jullien. 
The writer concludes that metals do not combine with each other ; that iron 
does not unite with either carbon, silicon, or nitrogen ; and that a mixture of 
hydrate of lime and dry hydrated sulphate of soda presents all the characters 
of a solution, but none of those of combination. Some of M. JuUien’s views, 
though put forward as original, have a strange resemblance to those long since 
announced by Dr. Matthieson, F.K.S., in his important memoirs upon the 
nature of alloys. Liquid cast-iron, he says, is a solution of liquid carbon in 
licjuid iron ; soft steel is a solution of amorphous carbon in either amorphous 
or crystalline iron. Grey pig-iron, obtained by casting in hot moulds or 
sand, is a mixture of graphite and steel, the components, iron and carbon, 
being both in the amorphous condition. Graphite, being amorphous, according 
to M. Jullien, carbon cannot crystallize without becoming diamond ; the 
supposed crystals of graphite are really casts of other crystals. Some of M. 
J ullicn’s other conclusions are equally startling. For example : — Liquid glass is 
the solution of a neutral silicate in one of its components ; granite is liquid glass 
slowly cooled ; lava, liquid glass suddenly cooled. Bronze slowly cooled is a 
solution of crystallized tin in amorphous copper, and bronze cooled suddenly is 
a solution of amorphous tin in amorphous copper. — Vide Comp>tes Rendus, 
January 25th. 
A Nev) Form of Safety-lamp for Miners has been devised by Mr. F. Foster. 
The most important feature in the invention is that the moment the lamp is 
Opened the flame is extinguished. It is well known that many of the dreadful 
