Amador ledger., 1909-10-15

land is the origin of the so-called dene-
holes that are so numerous in that To-
calty. They we're sunk in the chalk at
some prehistoric time, and usually con-
sist of narrow shaft Is or 100 feet
deep ending in a chamber 80 to so feet
in diameter, and l6 or l8 feet high, or a
series of two or three or more chambers.
They occur in groups. about 60 pits at
Hangman's Wood, Essex. being con-
tanned in the space of few acres A
late inquirer, Rev. J. w. Hayes, has
investigated the character of the chalk
deposits, and the ancient and modern
uses of chalk, and he offers an ex-
PLANTATION of the pits quite different
from the theories that have been most
favored. His view is that the dene
holes were simply quaries of chalk.
The export of the material began in pre-.
Roman times, and it was natural to
make the pits in groups where the strata
supplied solid blocks and the location
was convenient Buckets, or baskets
were used for raising the material taken
out. 1t has been widely believed that
the pits were made for granariees or
places Of refuge or both, but strong
evidence against these ideas is the fact
that many worked out pits contain water
from later excavations.
After four years of vain effort to pro-
duce an epidemic among rats, M. de
Kruvff, of the agricultural bureau at
Buitenzorg, lava, hit upon new plan
Pouring half teaspoonful of carbon di
sulphde into each occupied rat hole, he
lighted the vapor, and the poisonous
gases from the explosion almost instant
" killed all rats. In .,43 holes subse-
quently opened, l3l dead rats were
found, two holes containing 10 rats each.
A typical lunar landscape has been
initiated in a curious way by Paul
Fuchs, German experimental. Iron
ore Stag from smelling furnace was
run off at 100 deg. c., and cooled with
water applied in various ways. Craters,
mountains and plains were produced &C
cording to the conditions of the Stag and
the cooling.
Deaf-mutes are seldom absolutely
unable to hear any sound, and by
measuring their perception and properly
cultivating their powers, many of them
may be given a very useful degree OF
hearing AS the voice cannot be varied
at will in quality, pitch and intensity,
Dr. Marage, the French specialist, has
developed a more accurate acoumeter,
or measure of addition. Five sirens
coupled together give the fundamental
vibrations of the five vowels, and this
apparatus gives sounds of constant
quality that have a known pitch vary
ing with the speed of the motor and a
known intensity changing with the pres
sure of the air traversing the machine.
With the ear at distance of 20 inches,
the intensity of sound is raised by in
creasing the air-pressure until the vi
brations are perceived. The normal ear
hears sound produced under a pressure
Of millmete and if the pressure must
be raised to 60 millimeters to make the
sound heard the sharpness of hearing
is put down at l-60 and so on. If there
is no hearing at 200 millimeters, the
test is continued with a tube from the
siren to the ear. The perception varies
for the different sounds, and record is
made in five divisions showing the SEN
sitiveness of the hearing for each of the
vowels. The ears capacity being
known, it is trained by the simple and
exact vibrations of the vowel siren. In
suitable cases, hearing develops rapidly,
and results are reached in two months
that would require several years, with
great exertion and fatigue, to attain by
voice teaching.
In novel French water sterilizer, the
water is led through spiral tubes sur
rounding a mercury vapor lamp, which
itself is in the form of a long glass
tube, illuminated by the passage of an
electric current through the contained
mercury-vapor This light is rich in
violet and ultraviolet rays. The bacteria
Of the water are killed by exposure to
these rays, and any solid impurities may
be removed by passing through an or
binary filter on its way to a steriized
container
In the wood-preserving process of
Capt Malenkovie, an Austrian, solu-
tions of salts of zinc or other metals
are mixed with huoride of sodium and
forced into the wood, which is then
! baatAd IN 100 doc Z The inSOluble