Amador ledger., 1907-05-31


and Artificial Indigo. Sound Proof
Bricks. ks.-Locomotives Without Fire.
Solid Coffee Extract.
The talking siren of DR.. Marage of
Paris, designed to measure the hear
ing. has series of moIds or mouth
pieces. each of which gives the sound
Of one or tie voWels when a current
of air is forced through it, the intens-
ity of the sound varying with the air
pressure. A sensitive manometer
cages the pressure and indicates the
condition of the ear. A pressure of
one millimeter gives a sound that can
be perceived by normal hearing, and
other pressures show different stages
of deafness, patient who hears only
when 200 millimeters is reached re-
quiring an ear trumpet. The acoustic
sense is stated at LAO for 40 miIli-
meters of pressure, 1-60 tor 60 miIli-
meters, and so on, this scale furnish
ing very accurate Indication of the
hearing power. The siren is useful
not only for diagnosis but as a means
of curing the trouble, systematic
course of sounding The apparatus III
the ear serving as a very efficient
massage. This nearly always effects
improvement, sometimes completely
restoring the nurmal hearing, and
has even taught deaf -mutes to hear.
The latest estimate of the erosion of
Niagara Falls-based on determination
of the crest in 1842, 1875, 1856, 1850
and 19O5-gives a mean wear of 5. 3
feet per year for the Horseshoe Fall
and o. to 0.5 foot for the American
Fall. 1he Horseshoe Fall has re-
treated 25o0 feet since it parted from
the American Fall, the separation
having probably occurred five centur-
les ago. Much of the water is now
diverted through the Erie, Welland
and Chicago Drainage canals, as we'll
as for power generation, and this
must affect future erosion.
Taking the electrical conductivity
of annealed copper as 100, that of
anneaIed silver is los, while that OF
pure water-which does not occur in
nature-has been found to be only
one mIIlionth (00O0O01), and that of
glass less than -billionth (O.QOO-
OOOOO1).
M ost novel of the improvements in
the new arc lamp of Tito Carbone; a
German engineer, is an electromaghet
for blowing the arc. This causes the
arc to take and keep hemispherical
shape, assuring regular wear of the
carbons, and the result is a greatly
increased illuminating power. Small
carbons are used-about third of an
inch in diameter with a direct cur
rent. A lamp using 10 amperes at ITO
volts, with a clear glass globe, was
tested by Prof. Wedding of Berlin,
and was estimated to have luminous
intensity in vertical direction OF
4. 4.0U0 candle power. An important
in addition to the great
power is that the oblique position OF
the carbons causes the arc and the
crater to project most OF the light
downward.
In novel method of toughening
lately brought out, the metal treated
is placed in closed retort with a
small quantity of mercury, the retort
is subjected to pressure, and as it is
heated to point below melting tenn
perature a current of electricity is
passed through the metal. Besides
increased toughness, greater resistance
is given to corrosion by sea-wateI and
other agents. Ihe hardening is
especially adapted for iron and steel,
but is claimed to be useful tor other
metals.
Synthetic indigo, which has been
gaining the market during the last
ten yeaIs, is pure lndigotine, while
natural indigo consists of this sub
stance with impurities that have been
supposed to be either inert or harm
full. Certain dyers, however, have
claimed better results for the natural
indigo. 70 settle the question, Cyril
Bergtheli, acting for Hungarian plant
ers has made tests with both dyes on
large scale and under Identical con-
ditions. He finds that the natural
indigo really does give darker
shade, with a richness or "bloom"
that is Invariably absent from goods
dyed with synthetic indigo.
The largest steam turbine yet under
taken is the one of 81 900 horsepower
that is being built at Mannheim for
the Krupp Iron Works in Kheinhau-
sen.
Various methods of making sound
proof building bricks or plates are
noticed by German authorities. The
chief constituent is caIcined gypsum,
aud it appears that in the simplest
process the mass is filled with fine
pores by adding small proportion of
such substances as the bicarbonates
of the alkalies, the chemical action