106 
POPULAE SCIENCE EEVIEW. 
frozen mass. McClellan Mountain is one of tlie highest eastern spurs of 
the snowy range ; it has the form of a horse-shoe, with a hold escarpment 
of feldspathic rock near 2,000 feet high, which in some places is nearly 
perpendicular. The Stevens Mine is situated in the southwestern bed of 
the great horse-shoe ; it opens from the northwestern. A tunnel is driven 
into the mountain on the lode, where the rock is almost perpendicular. 
Nothing unusual occurred until a distance of some 80 or 90 feet was 
made ; and then the frozen territory was reached, and it has continued 
for over two hundred feet. There are no indications of a thaw summer 
or winter ; the whole frozen territory is surrounded by hard massive rock, 
and the lode itself is as hard and solid as the rock. The miners being 
unable to excavate the frozen material by pick or drill to get out the ore 
(for it is a rich lode, running argentiferous galena from 500 to 1,200 ounces to 
the ton), found the only way was to kindle a large wood tire at night against 
the back end of the tunnel and thus thaw the frozen material, and in the 
morning take out the disintegrated ore. This has been the mode of mining 
for more than two years. The tunnel is over two hundred feet deep, and 
there is no diminution of the frost ; it seems to be rather increasing. 
The immense Extent of American Oil Districts. — According to a recent 
statement in the u Scientific American,” it seems that a late report on the 
Great Butler Oil District, covering the entire production of the country 
south and west of Pittsburgh, gives at present 596 producing wells and 81 
wells now drilling. There are 1,076 engineers employed. The working 
capital invested is $1,859,000. The daily production of oil in this district 
is 15,548 barrels, which indicates a large decrease within the past month. 
Mineralogical Communications , by Herr G. vom Bath. — These communi- 
cations consist, according to the u Chemical News,” of a contribution to our 
knowledge of the crystallisation and twin formations of tridymite ; descrip- 
tion of a remarkable crystal of calcareous spar from Lake Superior, apropos 
of which the author points out that a monograph of the modifications of 
calcareous spar would be a boon to mineralogists ; a peculiar specimen of 
rutil and iron-glance grown together ; remarkable crystals of artificial 
metallic copper ; the discovery of hypersthene in a trachytic rock, Rocher du 
Capucin , near the baths of Mont Dore in Auvergne ; and foresight, a new 
mineral of the zeolite family, from the granite 
consists of — 
veins of Elba. Foresight 
Silica . 
. 49*96 
Alumina . . 
. 27-40 
Lime . 
. 5-47 
Magnesia .... 
. 0-40 
Potash ..... 
. 0-77 
Soda 
. 1-38 
Water 
. 15-07 
100-45 
It is most nearly connected with desmin. 
Lectures on Crystallography at the Chemical Society. — We may state that 
a considerable number of F.C.S. and others have joined the lectures by 
Professor Maskelyne, at Burlington House. 
