18(57.J 
AMAN AC^lilcmi^TUKIST, 
373 
About IVrpetiial ^lotion. 
Men have spent fortunes trj-ing to Invent a machine 
that would run of itself, without winding up or any other 
help when it had once been started. Probably some are 
now trying to put wheels and springs and levers togeth¬ 
er, so that they will make their own i>ower, and some- 
leely will be likely to succeed when he can take hold of 
his boot straps and lift himself over a fence. If this 
seems too discouraging to hopeful but inexperienced in¬ 
ventors, we will say tliey may e.xpect to make a “ per- 
l>etual motion ’ machine, wheu they llrst discover some¬ 
thing which is not already in motion, or when they learn 
how to keep anything from peri)etual motion. “ Why, 
everything keeps still if nobody moves it,” says a young 
friend whoso tongue is always ready to move. What will 
you show us to prove it ? Take tliat stone lying by 
the roadside. It has lain there, you say, ever since you 
can remember; it has not moved a single inch. We 
know it looks so, but when we are seeking to know the 
exact truth, we have sometimes to use other instruments 
ns well as our eyes. First, we will take the microscope. 
-\11 over the rough surface we discover tliat small parti¬ 
cles of that Slone are missing. They have left marks in 
the places which they once occupied, but they have gone 
on their travels. Some have mounted into the air and 
gone flying through space as dust; some have escaped in 
the drops of water which fell from the clouds, and car¬ 
ried them down to the ground, where hungry roots of 
grass and other plants were waiting to draw them in and 
send them circulating through their veins. If the stone 
had been accurately measured many years ago, an exact 
measure of it now would show that many particles ou the 
outside had moved or been carried away. Another exam¬ 
ination many years hence would show more to be miss¬ 
ing; so we must conclude that thev are now in motion, 
very slowly perhaps, but yet moving. We will apply 
another test. During a hot day hold the thermometer 
against the stone ; the mercury rises in the tube ; the 
stone is heated more than the air around it. Now we 
know that heat makes stone as well as other things ex¬ 
pand. The little j)articles of which it is made separate 
slightly—they move when heat is applied from the sun, 
or anything else. When the air around the stone grows 
cooler, then the heat will pass out, the stone will con¬ 
tract, its particles will move up closer together. Now, 
as the temperature of the air is continually changing 
from hour to hour, the stone keeps moving, and its par¬ 
ticles are never wholly at rest; there is perpetual motion 
in it. Shall we examine some other object ? Do so 
for yourself, until we have space to say something more 
about this subject in the A(fricultitrbt. 
Rats. 
Gnaw, gnaw,—nibble, nibble,—day and night, in sheds, 
cellars and garrets! Surely there are no creatures so 
greedy as rats; bread, cheese and meat, or books, pa¬ 
pers and clothes carefully packed away—nothing comes 
ami^s. Even the hard wood of boxes, floors and doors 
is not safe from their sharp teeth. This gnawing pro- 
I)ensity is therefore very troublesome to us, but perhaps 
if we could change mouths with the rats we should be 
quite as greedy ; for in truth, this propensity is not only 
excusable in a rat but actually necessary to his existence. 
And this is tnie of many other animals besides ruts and 
mice, namely: rabbits, squirrels, and all the “gnawers,” 
or “ rodents,” as they are called scientifically. 
Instead of chewing on side teeth as we do, the gnawers 
use four little front teeth with bevelled edges—that is, 
with one side sharper than the other, like a chisel, and so 
they file or nibble their food. 
The teeth of most animals, once grown, remain of a 
certain size ; but the teeth of rats and other rodents con¬ 
tinue to grow like our finger nails, so that constant gnaw¬ 
ing is necessary to keep them down to the right length. 
We cannot, therefore, blame a rut for sjioiling our papers 
and wood, since his comfort, and even life, depends upon 
it. We are always sorry enough to lose a tooth, but to a 
rat such a loss is a far more serious misfortune, for the 
opposite tooth, having nothing to file against, grows 
longer until it bars the mouth. If both upper or under 
teeth were lost, the poor creature could not eat, and in 
a very shoft time would certainly die of starvation. 
A M'^oiiUerlnl Piinip. 
The heart of an animal is a miniature force-pump, hav¬ 
ing supply and discharge pipes, and complete sets of 
valves. It has a wojgd of work to do during a lifetime of 
seventy years. Each minute the human heart beats about 
seventy times, at each beat receiving and discharging two 
and one half ounces of blood. Thus, it must distribute 
175 ounces per minute, C5G pounds per hour, 7Jt tons per 
day; aud in 70 j'ears about 200,000 tons. No pump ever 
constructed by man has continued to work so steadily, 
without derangement, and without repairs—though that 
is saying too much ; for, by its wonderful mechanism, it 
repairs its own wear, until the end of life. 
ITse Plain 
Little boys sometimes put on their fathers’ boots or 
their big brothers’ clothes, and act as though that had 
made them larger aud more important; but nobody is 
deceived, and they are only laughed at. Young writers 
and speakers should remember this wheu clothing their 
thoughts with language. Never try to find large or high 
sounding words. They are not natural, they will be 
awkwardly used, will often show miss-fits, and expose the 
author to ridicule. An ambitious young student, in writ¬ 
ing his composition, thus attempted to describe a veiy 
dark night; “ tenebrious gloom obscured the darkening 
shade.” The teacher, ou reading it, remarked, “ tliis be¬ 
ing translated into plain English, means ‘ dark darkness 
darkened the darkening dark ;’ that is, I suppose, it was 
very dark.” A young lady thus expressed the idea of a 
fine sunrise ; “ the royal king of day, clad in glorious 
golden panoply of dazzling eft'ulgcnce, flooded tlie earth 
with gorgeous brightness.” “ It is easier to swallow a 
dictionary than to digest it,” remarked the teacher, ou 
reading that outburst. In all writing, strive to express 
the thought most clearly. Nobody cares to unwrap a 
dozen or more coverings to get at a small parcel of candy. 
If you have a pleasant idea, out with it in as few and 
l>laiu words as possible, and not oblige the reader to strip 
off a pile of waste word wrai)pcrs. Use the language in 
which you think and converse; that will be entirely nat¬ 
ural. In time you may learn to make it elegant. Strive 
for excellent thoughts, aud to express them cleaiiy ; they 
will be valuable even in the homeliest words, just 
as a beautiful face is attractive in the plainest garb 
rVew Puzzles to l»e Auswered. 
No. 284. 
No. 2S0. JUnstraled ts a ?t yc(ttilfe (Considerable stud? to solve it 
No. 281. Illustrated Rebus .—order of nobility is 
here represented ? 
No. 282. .—With two hands, no finger or thumb, 
I speak plainly, yet 
have no tongue; my 
face is attractive, 
mucli looked at, yet 
has neither mouth, 
nose, or eyes. I go 
almost constantly, 
having neither feet 
nor wings, but never 
advance a step with¬ 
out company. 
No. 283. What way No. 283. 
of cooking bivalves is shown in the above engraving ? 
No. 284. How does the foot in the engraving below 
represent that its owner is determined on success ? 
Answers to Prol>leius and Puzzles. 
Tlie following are answers to the puzzles, etc., in the 
September number, page 833. 
No. 275. Fiejure Puzzle.— 
(FS').. .No. 270. Double Puzzle. 
—A cat may be found con¬ 
cealed over the bird’s nest. 
She has the old bird in her 
mouth. The rebus is “ Cat¬ 
acombs." The combs in the 
beehives, on the fowls, mak¬ 
ing the fence, and the cur¬ 
ry-comb ou the ground, ful¬ 
ly supply the latter part of 
the word_No. 277. Enig¬ 
ma. —A. Shoe, (jmde7'stand- 
fnp is a well-spring of life.)_No. 278. Studij in Horse¬ 
manship.—Toxw the picture sidewise and the boys will 
evidently be thrown... No. 279. Illustrated Rebus .—As 
twigs are bent, trees are inclined... No. 273. Arithmeti¬ 
cal Ptoblem .—(August number, page 279.) 45.35 yds. 
Xlie Cafacoiiil»s. 
In the September Agiicultui'ist, page 333, it was stated 
that the word formed in the puzzle picture was of histor¬ 
ical interest, and our young readers were requested to 
find out wliat they could about the “ Catacombs.” As 
many of them may have no books at hand containing the 
information, we give the following brief sketch. They 
were rooms cut under ground in the rocks for the recep¬ 
tion of bodies of the dead. The first Catacombs were 
probably made in Egypt. In that country it was custom¬ 
ary to embalm the dead,and the “mummies,” as the em¬ 
balmed remains were called, were then placed in the Cat¬ 
acombs. An entire chain of mountains in tlie neighbor¬ 
hood of Thebes, is mined by these chambers for the dead. 
Those belonging to the royal families and wealthy classes 
were splendidly decorated with costly paintings. Valua¬ 
ble ornaments of gold aud silver were also used to adoin 
the mummies, but these have been despoiled long since 
by hostile invaders. Many of the paintings yet remain, 
their colors as bright as when first put on. These paint¬ 
ings represent scenes in the daily lives of the Ancient 
Egyptians, and give a complete histoiy of their manners 
and customs. It is estimated that not less than 400,000 
mummies were entombed in the Catacombs of Egypt, 
which gives some idea of their vast extent. 1 he most 
interesting Catacombs are those of Rome, which are also 
immensely large, running under ground for miles. In 
the times of persecution, the early Christians found 
refuse in their intricate windings, and lived and wor¬ 
shipped unmolested by the enemies of Christ. On this 
account these plaees arc held in great reverence by the 
Catholic population of Rome. The Catacombs of Naples 
are of still greater extent than those of Rome. At Paris, 
a lar<m part of the city had been undermined in quarrying 
stone for building purposes, leaving extended galleries 
and rooms. They were not used for burial places until 
17&4 when the remains taken from a cemetery were de¬ 
posited there. Frequent additions have been made Rom 
other burial grounds, until it is computed by good author¬ 
ities that the boucs of at least 3,000,000 people rest there? 
