Year: 1874

sciences. A COLLECTION OF engraVlngS,
which every one can make gradually and
at trifling expense, affords an inexhaus-
tible source of not only innocent but i'm
proving recreation. The stereoscope, of
all recently invented optical instruments,
is one of the most beautiful. Microscopes
are made SO cheaply that one might be
found in every parlor, and the collection
of insects, and curious vegetable and min
eral productions for examination, would
pleasantly occupy many an idle hour.


But, if you have not microscope, a
very good one can readily be made Of a
pretty high power, and sufficient for the
examination of small objects, thus: Take
piece of lead about a sixteenth of an
inch in thickness. Makea perfectly round
hole in it, of from an eighth to quarter
of an inch in diameter. Drop in this hole
drop of perfectly pure water, and you
will have double convex lens as perfect
as can be made by art, and of high mag
nifying power.


Narrow strips of glass, such as GLACIERS
cut from panes in fitting them, may also
be melted at the end into globules, which
answer very well for examining small OBJ
objects.


One of the prettiest things in the world
is the camera-obscura. 1t may be con-
structed in various ways. Make room
perfectly dark, excepting an opening in a
blind an inch across, and you will have
an inverted picture of the external land
scape, in all its beautiful colors, on the op-
posite wall, or on a white curtain. A
more perfect picture, but on smaller
scale, is found by placing convex lens
-an old spectacle glass will answer-in
the opening, or over it on the outside and
receiving the picture on sheet of thin,
oiled paper; or with looking glass it
may be thrown down upon table, which
should be covered with white cloth. The
camera obscura is formed upon the same
principal as the eye, and the picture of
external nature is like that whicn is paint
ed upon the retina.


There are some experiments in physics
modified by the will, which are full of
wonder and amusement Here is one
which science has never been able to ex-
plain:


Let one person lie down on the floor.
Select four Others, who must stand, one
at each shoulder, and one at each thigh.
They all stoop; and placing the forefnger
OF each hand under the shoulders and
thighs, attempt to raise the person from
the floor. This can be done by particu-
lar process. AT signal given by one Sc
lected to direct the experiment, the five
persons, including the one to be lifted,
draw in their breaths together, and
breathe out the same way-three full in
spirations. followed by three expirations.
If all has been done properly at the third
expiration the person on the floor may be
lifted slowly, and with scarcely any ap-
parent effort, upon the points of the eight
fingers as high as they can reach. The
persons lifting are not conscious of raising
more than weight of two or three
pounds, while the person lifted has sem
sation of buoyancy, as if he were rising
on air cushions. If person outside
touches one of those who are lifting, with
so much as the slightest touch of the fin
ger, it appears to break the spell, and the
individual who was rising so pleasantly
into the air falls through the fingers sud-
IDENTIFY and violently TO the floor.


No scientific man has given any expla-
nation of this phenomenon. 1t does not
matter in the least how heavy the person
is who is lifted. There is no preceptible
difference between man of a hundred
weigh and one of three hundred. Nor
does the strength of those who lift appear
to make any difference They must be
earnest and follow the directions and sig
mails of the leader. 1l


A piece of pine half an inch thick,
twelve or fourteen inches in length, and
made to taper to the ends may be made
to rest each end on a wine glass Now,
If struck down with quick blow, the
stick may be broken in two without
breaking the glasses. On the same prin-
ciple man may lie on the floor or across
two chairs, with heavy rock or light
anvil upon his stomach, and allow it to
be hammered with heavy black-smith's
hammer, when it looks to the spectator
as if every blow would take his life.


These experiments are of easy explana-
ton, as they depend upon the inertia of
matter and the gradual distribution of
forces. But who can explain the action
OF the boomerang "a crooked stick which
the native Australian will throw around
horse or tree, so that it will come
back to his feet. You can make a sort
OF boomerang with pasteboard. Take
piece four or five inches square; ; cut it
so as to leave two sides an inch wide like
letter L. Lay this on book so that
one end will project over the side about
an inch. Strike it smartly with small
rod and it will go flying a short distance,
stop, hover In the air moment, and come
back to your feet.


An instantaneous and intense light has
sometimes been sprung upon party so as
to produce CONSERVATION and amusement
according to circumstances. Suppose the
room darkened for any ostensibie object
such, for example, as the exhibition of
the magic lantern. Have in small plate
few grains of equal parts of powdered
loaf-sugar and chlorate of potash mixed to-
gether. Touch the powder with a drop
OF sulphuric acid and you have light SO
intense that the eyes can scarcely bear it.


There are hundreds of beautiful expert
ments in chemistry, magnetism, and cleo
tricity, which afford fund of amusement
and food for thought. A French naturalist
said, he could spend whole life time with
pleasure and profit in examining SO much
of the earth as he could cover with his
hand. With the vast domain of science
| open to us, we can never want for amuse