" means its
evaporating power, and in that sense is proper. If its evaporative
power be sufficient to perform a given amount of work, it is proper
to estimate that work in horse power. Water can not be pumped out of a
pipe from which atmospheric air is excluded. A pipe driven into a soil
impervious to air, can never yield water unless the water is forced up
by hydraulic power, as in the artesian system.

A. P. Y., of N. Y.--You will find descriptions of iron enamelling
processes, on pages 297 and 408, Vol. XII. of this journal. It can be
done in colors. See Ure's "Dictionary of Arts and Manufactures."

H. C., of Pa.--We do not think increasing the size of the journals of
your car axles from 21/2 inches to 6 inches diameter, would make them
run lighter.

H. H. A., of N. Y.--The lining up of a beam engine, in a vessel, is
a process for which no definite mode of procedure is exclusively
applicable. It is an operation to which common sense and judgment must
be brought, and for which each engineer must be a law unto himself.

J. S., of Va.--The use of horizontal propellers to force balloons up
or down is not a new suggestion. It has been tried, but, we believe,
without much practical success.

J. T .S., of N. Y.--You will find further information on the subject
of transmitting power by compressed air, in our editorial columns of
last week.

* * * * *

APPLICATIONS FOR EXTENSION OF PATENTS.

HARVESTERS.--William T. B. Read, Chicago, Ill., has petitioned for an
extension of the above patent. Day of hearing, May 17, 1871.

MODE OF FASTENING SHEET METAL ON ROOFS, ETC.--Asa Johnson, Brooklyn,
N. Y., has petitioned for an extension of the above patent. Day of
hearing, May 3, 1871.

METHOD OF PRINTING IN COLORS.--Rosalie Croome, Brooklyn, N. Y., has
petitioned for an extension of the above patent. Day of hearing, May
3, 1871.

MACHINERY FOR COMPRESSING GASEOUS BODIES.--William A. Royce, Newburgh,
N. Y., has petitioned for an extension of the above patent. Day of
hearing, May 10, 1871.

PLOWS.--John S. Hall, Pittsburgh, Pa., has petitioned for an extension
of the above patent. Day of hearing, May 17, 1871.

CARRIAGE WHEELS.--James D. Sarven, New Haven, Conn., has petitioned
for an extension of the above patent. Day of hearing May 24, 1871.

* * * * *

NEW PATENT LAW OF 1870.

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