We give herewith an illustration of a compact engine, designed by
Messrs. Merryweather & Sons, of London, particularly for mining work,
and already supplied to the Burma ruby mines, the Salamanca tin mines,
and several mining companies in Brazil and other parts of South
America. It is an arrangement of the Valiant steam pumping engine with
a flywheel arranged to take a belt, and is so constructed that the
pump can be readily thrown out of gear and the engine used to drive
light machinery. The smaller size weighs only 7 cwt., including
boiler, engine and pump complete, and can be run on its own wheels, or
these can be detached and the machine carried by eight or ten men on
shoulder poles passed through rings fitted on top of the boiler. Thus
it can be easily transported up country, and has for this reason been
found most useful for prospecting. For alluvial mining it will throw a
powerful jet at 100 lb. to 120 lb. pressure, or by means of a belt
will drive an experimental quartz crusher or stamp mill. The power
developed is six horses, and the boiler will burn wood or other
inferior fuel when coal is not obtainable. The pump will deliver 100
gallons per minute, on a short length of hose or piping, and will
force water through three or four miles of piping on the level, or, on
a short length, 35 gallons per minute against a head of 210 feet. The
pump is made entirely of gun metal, with rubber valves, and has large
suction and delivery branches. Air vessels are fitted, and the motion
work is simple and strong. The boiler is Merryweather's water tube
type, and raises steam rapidly, while the fittings include feed pump,
injector, safety valve, steam blast and an arrangement for feeding the
boiler from the main pump in case of necessity.
[Illustration: MERRYWEATHER'S PUMPING ENGINE.]
We are indebted to The London Engineer for the engraving and
description.
* * * * *
Some romances and exaggerations of which the Pitch Lake, at
Trinidad, has been the subject, are corrected by Mr. Albert Cronise,
of Rochester, N.Y. Its area, height and distance from the sea have
been overestimated, and a volcanic action has been ascribed to it
which does not really exist. It is one mile from the landing place, is
138 feet above the sea level, is irregular, approximately round, and
has an area of 109 acres. Its surface is a few feet higher than the
ground immediately around it, having been lifted up by the pressure
from below. The material of the lake is solid to a depth of several
feet, except in a few spots in the center, where it remains soft, but
usually not hot or boiling. But as the condition of the softest part
varies, it may be that it boils sometimes. The surface of the lake is
marked by fissures two or three feet wide and slightly depressed
spots, all of which are filled with rainwater. In going about one has
to pick his way among the larger puddles and jump many of the smaller
connecting streams. Each of the hundreds of irregular portions
separated by this network of fissures is said to have a slow revolving
motion upon a horizontal axis at right angles to a line from the
center of the lake, the surface moving toward the circumference. This
motion is supposed to be caused by the great daily change in
temperature, often amounting to 80°, and an unequal upward motion of
the mass below, increasing toward the center of the lake. A few
patches of shallow earth lying on the pitch, and covered with bushes
and small trees, are scattered over the surface of the lake.
* * * * *
The Gardeners' Chronicle announces that Mr. Fetisoff, an amateur
horticulturist at Voronezh, Russia, has achieved what was believed to
be impossible, the production of jet black roses. No details of the
process have been received.
* * * * *
Recent Books.
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ELECTRO-METALLURGY. Electric Smelting and Refining: The Extraction
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EXPERIMENTAL SCIENCE. By George M. Hopkins. This book treats on the
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arithmetical problems comprise all of the mathamatics of the book.
Many new experiments are here described for the first time. It is the
most thoroughly illustrated work over published on Experimental
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EXPLOSIVES. Lectures on Explosives. A course of Lectures prepared
especially as a Manual and Guide in the Laboratory of the United
States Artillery School. By Willoughby Walke, First Lieut. Fifth
United States Artillery. Second edition. Revised and enlarged. 8vo,
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FEEDS AND FEEDING. A Handbook for the Student and Stockman. By W.A.
Henry. 8vo, cloth. 657 pages. 1898 $2.00
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