Staunton spectator. [volume] (Staunton, Va.) 1849-1896, 1885-02-18
SCIENTIFIC MISCELLANY.
For the SPECTATOR. I

For the SPECTATOR.
A MICROSCOPES 'sFIELD.''-GIeat as are
the wonders the microscope reveals, it will
not-as is sometimes supposed fly
magnifed to the size of an elephant, nor a
flea of horse-like proportions, for the reason
that under high power only very small
part of either of those creatures can be seen
at one time. The size Of the field Of view
covered by ordinary lenses has been COM
puted as follows: With a power Of 25 d.
ameters, about one-fourth of an inch; with
so diameters, one eighth of an inch, with
100 diameters, one sixteenth of an inch; with
500 diameters, one-eightieth of an inch; and
with 1000 diameters, one one-hundred-
fiftieth of an inch, space ordinarily invisi-
BILE to the naked eye. Even the smallest
creature shown to our unaided vision, there
fore, cannot be seen entire when magni6ed
1000 diameters.
AN INTERESTING CELESTIAL VISITOR
Encke's comet, which travels around the
sun in about three and nalf years without
going beyond the boundaries of the solar
system, and which has the honor of being
the first known comet of short period, is
chiefly remarkable on account of the retar-
dation of its motion. This has amounted to
about four days since 1919, and is supposed
by some astronomers to prove the existence
of resisting medium in space. The date
of the comets perihelion passage this year
is March 7th, and its return was first OBJ
served Dec. 18Th. 1t is visible only with a
telescope.
A POWERFUL APPARATUs.-The largest
electrical influence machine in the world
has just been made for 1t1ss physical iaDcra-
tory tory at South Kensington. Its discs are
seven feet in diameter, of plate-glass three
eighths Of an inch thick, and weigh $50
pounds each. Tested under unfavolable
conditions, the machine has given constant
stream of sparks fourteen inches long.
THE EAR s CAPAClTY.-It has been found
by DR.. Lawson TAFT that, as a rule, the ear
in women can perceive higher notes-that
tions per second-than the ear in men. The
highest limit of and ability for the human
ear is somewhere between Al 1000 and AZ, 900
vibrations. The ears of most persons seem
to be unequally sensitive to acute sounds,
the right ear usually hearing higher note
than the left. TO show the ears range, it
may be added that very low notes of about
fifteen vibrations per second may be per-
ceived, but when the vibrations become a
little slower they cease to produce the eff
feet of continuous sound, and each gives
separate impression upon the ear.
EARLY BIRDs.-Prof. Huxley has remark
ed that while birds now constitute we'll
defined group, nobody mistaking the forms
included therein, we find the case to be diff
ferent when We turn to the geologi-
cal record. Fossil forms are found that
present definitions do not embrace, indicat-
ing wider range of structure, and the exis-
tence of types intermediate between birds
and reptiles.
A pressure of forty to 1870 atmospheres,
exerted during period of fifteen years, has
been found by Quincke to be incapable of
forcing perceptible quantity of carbonic
acid or hydrogen gas through a glass wall
one-sixteenth of an inch thick.
On keeping fatty oils several hours at a
temperature of four degrees below zero,
Sierra Carpi has obtained solids of remark
ably different degrees of hardness A mi
mute cylinder of iron was only forced into
solidifed olive oil by pressure of 1,7OO
grams, while cotton oil required but 90
grams.
The artificial heat of London has been
estimated to be sufficient to raise the tenn
perature of an air stratum 100 feet thick
over the entire city p degrees every hour.
INEQUALITIES OF SEA LEvEL.-A study
and comparison of the ocean temperature
records of the Challenger exploring expedi-
ton have shown DR.. James Croll that the
surface of the Atlantic must be lower at the
equator than farther north, the maximum
height of the North Atlantic being reached
between the fortieth and fiftieth degrees of
latitude. This difference is due to the diff
ference in the specific gravity of the water.
In the latitude of Havana the Atlantic's
surface must be two and one-f fourth feet
higher than at the equator, and in that of
Chesapeake Bay the difference is foot
greater.
large amount Of oil exists in the stormy
petrol, and when fat, according to Brun-
nick, the Inhabitants of the Farce Islands
use it as lamp, obtaining their light from
wick drawn through the birds body.
A collection Of skulls from the southern
hemisphere has been studied in England,
the most notable conclusion reached being
that some of the races of South Africa,
Australia and the southernmost part of
South America are remarkable for the
smallness of their heads.
The oldest geographical society has been
generally regarded as that of Paris, but &C
cording to DR.. Ruge that honor belongs to
the Cosmographic Society of Nuremberg
1t was established about 174O while the
Paris society was not founded until 1921
A Swiss geographer estimates that the
worlds geographical societies now contain
3e, 900 members.
r~1s c1, .4n~,, ,4r