u,.:- • - Clpdigital.org

46 THE COAL TRADE BULLETIN.
Meridith Bros 510
Thomas McBride 502
William Ackersan 500
Buchanan Bros 500
William Vicary 500
176 Small mines producing less than 500
tons each 38,754
Total 4S,717,853
NEW FIRE-DAMP DETECTOR.
A new device for detecting fire damp in mines
has just been invented by two young chemists,
junior teachers in the Technical College in this
city, writes Consul General John P. Bray, Sydney,
Australia.
The new detector is a simple and portable bit
of apparatus, designed for the purpose of detecting
and indicating the presence of fire damp
and other dangerous gases in coal and other
mines. Its warning is given either by a loudsounding
alarm bell, or by the flashing into view
of a red glow light. The makers of this simple
contrivance have based their procedure upon
Graham's law of the diffusion of gases, viz, "all
gases tend to diffuse into one another at a definite
rate, which varies in an inverse ratio to
the square root of the density of the gases."
Taking also Ansell's fire-damp detector as an
additional starting point, the inventors have succeeded
in procuring an efficient instrument which
an inspector or miner may carry in his hand and
test with ease and certainty the air in any heading
or at any working face.
The apparatus consists of merely a piece of
glass tubing bent into U shape, with the lower
curve flattened. One leg of the U has an ordinary
"shell" funnel at its upper end, and the
open mouth of this is covered by a thin disk
of plaster of Paris, mixed thin, so that in drying
it remains porous. The other leg is crowned
by a small reservoir containing additional mercury,
W'ith a little glass tap to allow the metal
to be run into the bent tube below as and when
required. Through each lower leg there is passed
a fine platinum wire, that of the funnel-crowned
one being about half an inch below the level of
the other, and immersed in mercury, which fills
the bend of the U up to this level. Each wire
is connected to the poles of an ordinary battery
cell, and thence effective connection is made with
either alarm bell or colored light.
What happens when' the detector is brought
into the presence of an admixture of gas and air
is simply this: The foreign gas permeates the
plaster of Paris seal and depresses the mercury
column below. This naturally causes the mer­
cury in the other leg of the U to rise and its
rise brings it into contact with the platinum
wire just above it. This slight contact is sufficient
to complete the circuit, and set either bell
or danger light to work. So sensitive is the apparatus
that, as shown by tests during the recent
exhibition, it can be adjusted to give warning
of the presence of such a small proportion
as 2 per cent., or even less, of an undesirable
gas.
JUNE ANTHRACITE SHIPMENT.
The shipments of anthracite coal over the vari­
ous' roads for June, as compared with 1910, were:
1911. 1910.
Philadelphia & Reading 1.135,749 911,713
Lehigh Valley 1,214,852 1,002,193
Central R. R. of N. J 876,579 716,548
Delaware, Lacka. & Western 906,722 894,121
Delaware & Hudson 604,055 605,120
Pennsylvania 481,004 455,923
Erie 783,083 574,109
Ontario & Western 213,313 238,396
Total 6,215,357 5,398,123
The shipments by months for the year, as compared
with 1910, were:
1911. 1910.
January 5,904,117 5,306,618
February 5,070.948 5,031,784
March 5,996,894 5,174,166
April 5,804,915 6,224,396
May 6,317,352 5,679,661
June 6,215,357 5,398,123
July 4,202,059
August 4,996,044
September 4,967,516
October 5,622,095
November 6,071,746
December 6,231,578
Total 35,309.583 64.905,786
Howard Neely has been appointed receiver for
the Pitcairn Coal Co., of Pitcairn, on petition of
Mrs. Annie Thomas, F. L. Miller, Robert D. Mc-
Daniel, Mrs. Christina McDaniel and J. A. Wilson,
stockholders. The receiver was ordered to
wind up the business of the company at once,
pay the creditors and distribute the balance to
the stockholders. The receiver also was authorized
to compel Anson E. Bonford, president of
the company, to turn over the proceeds received
from the unauthorized sale of certain lands belonging
to the company.