Amador ledger. (Jackson, Amador County, Calif.) 1875-19??, 1907-06-28

chiefly an ornament, as the ordinary
instrument requires troublesome cal
culations to show anything like true
time, and it can be consulted only
during hours of sunshine. The photo
heliometer shown at the late soiree of
the London Royal Society is an i'm
proved un-dial giving direct time
readings with sufficient precision for
regulating common clocks and
watches. 1t consists essentially of q
ball-and socket stand for adjustments
in latitude and level, an hour circle
which can slide round to follow the
apparent motion of the sun, and a
year circle on which are engraved the
months. Greenwich mean time is
indicated when the hour circle is
moved so that the spot of light COM
ing through an upper screen falls on
the central line. The year circle is
turned to indicate the current day
and month, and a cam or curved
plate on its under side automatically
applies the necessary corrections.
Practical joking with even mild
shocks of electricity is not to be com
mended. Some workmen in a Shelf
field machine shop recently connected
live wire to a metal door knob, and
requested that certain chosen fellow
workmen open the door. One man
was killed instantly. The current
was not powerful, but the post
norton showed that the victim had
rare and unsupported disease known
as lymphatism, which made him
liable to sudden death from a slight
shock of any kind.
Copper is stated to be so hardened
as to take cutting edge by adding
to it, while in molten state, about
two per cent of potassium ferro-
cyanide. The color is not affected.
The reason for the change Is not clear,
but it Is supposed to result from the
introduction of iron and possibly
carbon.
The teeth of a nation are a much
neglected asset, and the British
Dental Association has been consider
ing means for improvement as a
national affair. Investigations have
indicated that not more than three
per cent of all children of school age
have sound teeth. How great is the
influence of this in retarding develop
ment and producing weak and i'm
properly nourished bodies cannot
easily be estimated, but it is doubt
less true that much dyspepsia and
illness have resulted from poor teeth.
In the South African war the in
ability of the soldiers to masticate
ordinary food caused enormous waste
of supplies, while defective teeth ex
part of army recruits. 10 bring
about reform it seems necessary to
make attention to the teeth of school
pupils public matter, and con-
sentative estimate is that Great Bri-
tain's outlay for this purpose should
be at least Sc, 900, 0G0 year
The curious thinness of some skulls
of Egyptian mummles of the fourth
10 the nineteenth dynasties has been
studied by DIR. q. Elliot Smith, pro-
lessor of anatomy at Cairo, and he
suggests that the cause may have been
the wearing of heavy wigs. 1t occurs
in both male and female skulls. 1t
is found only in mummies of wealthy
people, and the upper classes of the
period to which the phenomenon be-
longs are known to have followed the
| fashion of wearing enormous wigs.
Intermittent pressure, such as that of
the water jars carried by modern
fellaheen women, does not seem to
affect the blood supply sufficiently to
cause the bone atrophy.
The special camera of DR.. j. K.
Milne is designed to record automati-
calIy the readings of the scale of any
instrument. On using any apparatus
having a scale and vernier, the Oh
server registers a reading by simply
pressing a bulb, which causes the
camera to make a photograph on q
small section of its sensitive plate,
which is then moved along automati
calIy, and can be made to receive
seventy records.
A distance meter for vehicles OF
ships was used by the Romans in the
time of Caesar, and late German
writer notes that Vltruvius, IN curl.
GUS chapter on architecture, referred
to it as an ancient device. 1t was
necessary that the chariot wheel
should have a circumference of 12E
feet or 1-4O0 of a Roman mile Il, 00(
feet). A second wheel geared to this
one was driven at the same rate
showing an advance of 121a feet fol
each revolution and at each turn o.