440 Miscellaneous Intelligence, 
ble, owing to the enormous superincumbent mountain mass, to operate at 
more than two places. The mountain rises to the height of one thousand 
to fifteen hundred metres (3280 to 5000 feet, nearly) above the level of 
=33 miles). They could not think of setting up boilers in the tum 
itself, since it was plain there would be se 
distance. The colum 
of the hydraulic ram is 25 metres high by 60 centimetres in diameter, 
the compression of air in the reservoir of the ram at the moment of fall is 
six atmospheres—at this instant a valve yielding at five atmospheres 
and a part of the compressed air escapes into immense boiler-like reser 
voirs. Five or six of these apparatus are needed for the regular p' 
of the work in the tunnel. The inventor of this remarkable apparatus, 
Mr. Tommelier, is director of the works. It is impossible to conovive 47 
thing be i rer 
ing better adapted for a mountainous country where sme which 
as 
ye t the 
ore quickly 
tis nel if 20 Cos 
