108 
AMERICAN AGRICULTURIST. 
[March, 
ranged the strings, which may be easily done by putting 
a short cord or a wire around the dish, and attaching the 
Fig. 3. Fig. 4. 
other cords to that; fill the cup with water, twist the 
strings together as in figure 4; hold up the cup and watch 
what takes place. As the cup revolves by the untwisting 
of the strings, the water, following the law of centrifugal 
force, will try to get as far from the center as possible; 
it will at first become hollow on the surface, and so soon 
as the motion is swift enough will be thrown over the 
rims to such a distance that may make it pleasanter to 
hang up the cup than to hold it. 
This tendency of water to fly off from 
bodies in motion is made use of in 
factories and bleacheries where they 
have large quantities of cloth and 
yarn to be dried; the wet materials 
are placed in a cylinder of wire 
gauze, which is made to revolve from 
1,000 to 2,000 revolutions in a minute. 
In a very short time the water is all 
thrown out by centrifugal force, and 
the material is taken out quite dry. 
In a similar manner much of our 
HONEY IS EXTRACTED PROM COMBS. 
The best bee hives now have mov¬ 
able frames in which the bees build 
their combs. When the bees have 
filled their cells with honey, the 
frames of comb are taken out of the 
hive, and the caps of the cells being 
first cut away, are placed in an “ ex¬ 
tractor,” where they are rapidly 
whirled; the honey is thrown out by 
centrifugal force, and the combs are 
returned to the hive for the bees to 
fill again. The same principle is 
made use of in draining molasses 
from sugar. An express or freight 
train moving with great speed 
ON THE CURVES OP A RAILROAD 
has a tendency to fly off by centrifu¬ 
gal force, and you will notice that an 
accident from that cause is guarded 
against by placing the outer rail on such curves some inches 
higher than the inner one. The statement that a pail or 
other vessel filled with water may be placed upside down 
without any of the water run¬ 
ning out, seems at first quite 
improbable. It can easily be 
done, provided it does not 
remain in that position too 
long. As a pail would be too 
large for a boy to manage, 
you can do better with a tin 
kettle, or better still, with an 
old fruit can. It will, be an 
easy matter to fasten a bail to 
a fruit can and a stout cord 
to that. Then, by care, the 
can quite full of water may be 
swung around so that the mouth will be directly down¬ 
wards, as seen in figure 5, and not a drop will fall out. 
Success with this interesting experiment consists in 
Fig. 5. 
PROPERLY STARTING AND STOPPING. 
You should first swing it back and forth like a pendu¬ 
lum, increasing the oscillations until by a skillful move¬ 
ment you can get a rotary motion. In this, the centri¬ 
fugal force has such a tendency to carry the water off in a 
straight line that it overcomes the attraction of gravita¬ 
tion. I have seen the action of centrifugal force on 
liquids illustrated very prettily with a glass globe, in 
which a small quantity of water was placed, and colored 
dark-blue to make it more readily seen. This was at¬ 
tached to gearing, which would cause it to revolve rapid¬ 
ly, and it was very interesting to watch the movements 
of the water in the attempt to obey the centrifugal force 
and fly off, it of course being stopped by the glass. It 
gathered in a narrow band as 
far from the center as pos¬ 
sible, and so long as the 
globe was in motion staid as 
a narrow band (fig. 6) against 
the glass. Some one has 
made a rather amusing cal¬ 
culation, which shows that if 
the earth revolved only 17 
times faster than it does now, 
the centrifugal force would 
be sufficient to overcome the 
attraction of gravitation ; if 
it went around on its axis in 
a little less than an hour and 
a half, instead of taking 24 
hours, all movable things 
would fly off by centrifugal 
force, the water included; the seas would become dry, 
and the imagination can hardly picture the consequences. 
But it is hardly worth while to consider how things 
would be if they were not as they are. Such calculations 
do but little good. I doubt if it will make one happier 
or better to know that had the builders of the tower of 
Babel only carried their structure to the hight of 24,000 
not—comes out as clear as daylight to your own delight. 
The same principle of optics (as this branch of science 
which treats of light and eye-sight is called) is shown in 
various other ways; one of the most common methods 
consists in taking a card, with a cage drawn on one side 
and a bird on the other, and strings attached as shown in 
figure 3 The trick being to put the bird in the cage. 
Again, a horse is put on one side of the card in a gallop¬ 
ing attitude, figure 4, and the rider on the other, figure 5, 
when by whirling, as in the other cases, the two objects 
appear together as one picture, figure 6, because, as the 
juggler would say, “ the hand is quicker than the eye.” 
Fig. 1.— THE BRISTOL-BOARD PATTERN. 
Fig. 2.— THE WHIRLING PUZZLE FINISHED AND BEING WHIRLED. 
miles, the stones, or bricks, at the top would have all 
gone flying off by centrifugal force. The Doctor. 
A Whirling 1 l*uzzle. 
Perhaps you have done it many a time; if not, try it. 
Take a dry pine stick, and light one end of it; let it burn 
for a few minutes, blow out the flame, and a live coal 
will remain. Now hold this stick by the cool end, and 
move the other rapidly around in a circle; a bright 
ring of light is produced. This is due to the fact that 
the impression of the object upon the eye is not in¬ 
stantaneous, but- remains for one-third of a second. 
During the short time of a third of a second the coal has 
passed through a considerable space, and therefore the 
impressions in all its different positions are received and 
become blended into a line of light. This duration of 
the impression which an object makes has made many 
tricks, etc., possible, some of which are very puzzling 
until understood. Figure 1 represents a piece of Bristol 
board, upon which two rows of peculiar looking figures 
are worked in yarn. The pasteboard is afterwards folded 
lengthwise through the middle, so that the lines come 
upon the center of each side, facing outward. A string 
is then attached at the middle of each end, and with a 
binding to secure the two halves the puzzle is complete. 
When seen for the first time the Thaumatrope is an ob 
ject entirely without meaning. It may be handed to a 
guest, with the request to read the inscription, as it was 
to the writer. The more it is turned this way and that 
way, the more puzzled and bewildered one becomes, until 
Fig. 4— THE HORSE. 
the strings at the ends are caught up and the thing is set 
in a whirl, when the reading—motto, request, or what 
As such puzzles are both curious and instructive, theyare 
worthy of a little time in construction from the young¬ 
sters. It is notone of those things that only the ingenious 
can make, but is within the reach of any one who can 
find a piece of pasteboard and the picture of a horse, a 
boy to put on it, and a couple of short pieces of string. 
The more elaborate design, given in figures 1 and 2, is 
for the older of the girls, which they can easily make. 
Our I*iizzle-IBox. 
SCATTERED SQUARE. 
(Find the first word [and initials] scattered in the first 
line of the following verse; the second word in the 
second line; the third word in the third line, and the 
fourth word in the fourth line.) 
We love to play where brooklets run, 
And violets open to the sun; 
We love along the lanes to stray, 
And cull the flowers by the way. 
METAGRAM. 
From a word of six letters, make all the words neces¬ 
sary to fill the following blanks. (Example .—Fill the fol¬ 
lowing blanks from a word of five letters. Father—me eat 
my—-and then go to-. The word is bread or debar, 
from which you may get bade, bread and bed with which 
to fill the blanks.) -1— -the other evening 
I saw-run across the floor. He had a piece of- 
in his mouth. I could do nothing but-at him ; but- 
chased him down to the-on the-of the house. We 
are considered a pretty-of folks, but it was a dark 
night, not a-to be seen ; and although-“ put on 
-” and ran at a pretty good-, the-escaped. 
CHARADE. 
My first is rather personal, 
Yourself it may be reckoned, 
And thousands of my whole ’twould take 
fiver to count my second. A, 8. 
CROSS-WORD. 
My first is in number but not in one, 
My next is in planet but not in sun, 
My third is in mischief but not in play, 
My fourth is in morning but not in day, 
My fifth is in order but not in rule, 
My sixth is in student but not in school, 
My seventh is in sofa but not in bed. 
My eighth is in scarlet but not in red, 
My ninth is in shriek but not in yell, 
My tenth is in prison but not in cell. 
My eleventh is in onion but not in beet, 
My twelfth is in mutton but not in meat, _ 
My thirteenth is in wisdom but not in mind: 
My whole is advice of an excellent kind. 
