440 
rOPULAR SCIENCE REVIEW. 
Leschol. The instrument lie uses is made out of a tube furnished with a 
circular cutter of rough diamonds.* 
Mining by Machinery . — Very little has yet been done to supersede manual 
labour in the excavation of mineral substances, but the matter is now 
beginning to receive attention. In metallic mines, Crease’s excavating 
machinery is said to be highly successful. The inventor engages that such 
machines, fitted with two augers, shall work at the rate of 500 to 700 
blows per minute, each auger independent of the other, and working at 
any angle whatever. 
Attempts have been made at various times to arrange machinery for 
getting coals, but until very recently none has stood the test of experience. 
It will be necessary to explain that in getting a seam of coal, the first 
operation is usually that called “ holing,” or “ undercutting,” which con- 
sists in making a horizontal excavation into the coal at the base of the 
seam by means of the pick. It is in this process that the chief labour of 
coal-getting consists ; and whoever has seen half-naked colliers engaged 
in this toil, kneeling, or perhaps lying on their side, must feel that it is 
very desirable to substitute machinery for such terrible work. Some years 
ago a coal-cutting machine was invented by Mr. Peace, of the Earl of 
Crawford’s Collieries, Wigan, in which an endless chain, provided with 
teeth, was made to revolve ; but it has long been disused. A machine has 
lately been invented, however, which is at present employed at the West 
Ardsley Colliery, near Leeds, and which bids fair to be very successful. 
It may be briefly described as a collier’s pick in the hands of a machine. 
The pick is made to act in any direction ; but for holing it will, of course, 
strike horizontally. The handle of the pick forms the long arm of a 
“bell-crank,” of which the shorter arm (which moves through a much 
smaller space) is actuated by the piston of a cylinder. To work the latter, 
compressed air is forced in pipes down the pit to the cylinder, and moves 
the piston just as steam would do, but with the advantage that the escape 
air assists in the ventilation of the working place. The whole machine is 
mounted on wheels, and can be run on tramways from place to place. 
PHOTOGRAPHY. 
T HE adjudicators appointed by the Council of the Photographic 
Society have awarded the prize medals for the best contributions 
in six distinct branches of photographic art, as follows 
M. Claudet, for the best portraits. 
Mr. Francis Bedford, for the best landscapes. 
Colonel the Honourable Stuart Wortley, for the best instantaneous 
pictures. 
Viscountess Hawarden, for the best amateur contribution. 
Mr. H. P. Robinson, for the best composition picture from life. 
Mr. Thurston Thompson, for the best reproduction. 
* A description of it will be found in our Continental Summary. 
