Scientific American Supplement, No. 433, April 19, 1884
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Various >> Scientific American Supplement, No. 433, April 19, 1884
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JOHN M. HUGHES.
Brooklyn, N. Y.
* * * * *
[FOR THE SCIENTIFIC AMERICAN.]
ON COMETS.
When we see a comet approaching the sun with its tail following in the
orbit of the nucleus, we have no great difficulty in believing the
common theory that a comet consists of nucleus attracted toward the sun,
while the tail is repelled; and that we see the whole of it. But as it
approaches the sun, difficulties arise that make us doubt whether the
theory be true.
Let us suppose a comet with a tail 50,000,000 miles in length, and that
it will require two days to pass round the sun. Now the tail, being
always in a line drawn through the center of the sun and center of the
nucleus, will, when it reaches the long axis of the elliptical orbit,
stand perpendicularly to the orbit of the nucleus. That is, the
extremity of the tail farthest from the sun, in addition to its onward
motion, has acquired a lateral motion that has lifted it 50,000,000
miles in the first day of its perihelion. The velocity of the extremity
has been vastly accelerated over that of the nucleus, and it has
moreover a sheer lift above the orbit of the nucleus. Now this lift is
in opposition to gravity; neither is it in consequence of any previous
momentum, for its velocity is accelerated and its previous momentum
would be a hindrance; nor is the lift in consequence of any repelling
force from the sun, for such force would be diminished in proportion to
the square of the distance, and the far end would be acted on less than
the nucleus end of the tail, whereas the velocity of the former is
increased a hundred fold over that of the latter. A polar force in the
comet would merely draw the comet into the sun. We therefore find no
force adequate for such a lift, but on the contrary all the forces are
opposed to it.
But if the first day of the perihelion overwhelms us with difficulty,
the second day will prove disastrous to the common theory. For the
extremity of the tail farthest from the sun will be required to pass
with lateral motion from its perpendicular 100,000,000 miles, so that it
may be in advance of the nucleus and again rest on its orbit. This orbit
is an impassable line, and therefore instantly arrests the prodigious
lateral velocity of the tail. That impassable orbital line is to it
as solid and inflexible as a wall of adamant. The motion so instantly
arrested would be disastrous to any tail, whether composed of gas,
meteorites, or electricity, whatever that may be.
Having shown that the common theory of comets is filled with insuperable
difficulties, I will again call attention to a theory proposed about
eighteen months ago in the SCIENTIFIC AMERICAN.
According to this theory, a comet consists of a nucleus and an
atmosphere, for the most part invisible, surrounding it on all sides to
an extent at least equal to the length of the tail. The rays of the sun
in passing through or near the nucleus are so modified as to become
visible in their further progress through the cometic atmosphere, while
all the rest remain invisible. What we call the tail is merely a radius
of the cometic atmosphere made visible, and as the comet moves through
space, only different portions of the atmosphere come in sight, in
obedience to the ordinary laws of light. There is no difficulty in
accounting for the rise and fall of the tail at perihelion, nor for the
tail preceding the nucleus afterward.
The spherical theory accounts easily for the different forms of tail
seen in different comets. The sword shaped tails, at variance with the
common theory, can be accounted for by supposing a slight difference in
density or material in the cometic atmosphere, which will deflect the
light as seen. The comet of 1823, which cannot be explained on the
common theory, is very easily explained on the spherical. That comet
showed two tails, apparently of equal length, which moved opposite to
each other, and perpendicularly to the orbit of the nucleus, and showing
no signs of repulsive force from the sun. On the spherical theory it is
only necessary to suppose such an arrangement of the nucleus as would
reflect the rays of the sun laterally; a slight modification of the
nucleus would give not only two but any number of tails pointing in
different directions.
It may be objected to the spherical theory that a tail 50,000,000 miles
long would call for a sphere 100,000,000 miles in diameter, and that
would be too vast for our solar system. But it is claimed for this
sphere that it consists of the same material as the so-called tail, and
that it has the same capability of moving among planets without manifest
disturbance to either.
The sphere at the perihelion would envelop the sun, and as a noticeable
reduction is sometimes found in its so-called tail, the cometic
atmosphere may impart to the sun at that time whatever is necessary to
its use.
That there is something in common between the sun's corona and cometary
matter was shown by the last solar eclipse observed in South Pacific
Ocean, where the spectrum of sun's corona was found to be the same as
that of a comet's tail. Are we to attribute in any degree the different
appearances of the sun's corona to the presence or absence of a comet
at its perihelion? At the eclipse of the sun seen in Upper Egypt two or
three years ago, a comet was seen close to the sun, but I have seen no
account of the appearance of the corona at that time.
FURMAN LEAMING, M.D.
Romney, Tippecanoe Co. Indiana.
* * * * *
FORMS OF IVY.
It is scarcely possible for us to bee too emphatic in our praises of the
most distinct forms of ivy, since but few other hardy climbing plants
ever give to us a tithe of their freshness and variety. A good long
stretch of wall covered with a selection of the best green-leaved kind
is always interesting, and never more so than during the winter months,
especially if at intervals the golden Japanese jasmine is planted among
them or a few plants of pyracantha or of Simmon's cotoneaster for the
sake of their coral fruitage. The large-leaved golden ivy is also very
effective here and there along a sunny wall, especially if contrasted
with the small-leaved kind--atropurpurea--which has dark purple or
bronzy foliage at this season. Of the large-leaved kinds, one of the
most distinct is canariensis, or large-leaved Irish ivy, and Raegner's
variety, with leathery, heart-shaped foliage, is also handsome. The
birdsfoot ivy (pedata) is curious, as it clings to the stones like
delicate leaf embroidery, and for shining green leafage but few equal
to the one called lucida. The two other kinds sketched are hastata and
digitata, both free growing and distinct sorts.
[Illustration: VARIOUS FORMS OF IVY. Heart-leaved Ivy (Hedera
Raegenerana). Glossy Ivy (H. lucida). Arrow-leaved Ivy (H. hastata).]
_Ivy Leaves_.--Common ivy is tolerably plentiful nearly everywhere, but
it is not common to find a good distinct series of its many varieties
even in the best gardens. Of all the different forms of ivy, I think
the large-leaved golden one of the best; certainly the best of the
variegated kinds. Raegner's variety is also very bold, its great glossy,
heart-shaped leaves most effective. Algeriensis is another fine-leaved
kind, the form dentata producing foliage even still larger when well
grown. For making low evergreen edgings on the turf, for carpeting
banks, the covering of bare walls and the old tree stumps, we have no
other evergreen shrub so fresh and variable, or so easily cultivated as
are these forms of the ivy green. Perhaps one reason why the finer kinds
of ivy are comparatively uncommon is the fact that a strong prejudice
exists against ivy in many minds. It is an erroneous notion that ivy
injures buildings against the walls of which it is planted; it never
injures a good wall, nor a sound house, but on the contrary, hides and
softens the stony bareness of the one and adds beauty and freshness to
the other.--_The Garden_.
[Illustration: VARIOUS FORMS OF IVY. Finger-leaved Ivy (H. Itata). Irish
Ivy (H. canariensis). Rira's foot Ivy (H. pedata).]
* * * * *
PROPAGATING ROSES.
In an article on this subject an English horticultural journal describes
the method pursued by a London florist. After stating that out of a case
containing 310 cuttings only five failed to root, the article proceeds:
The case or box is made of common rough deal boards. It is five feet
six inches long and one foot in depth. Within half an inch of the top a
groove is cut inside the box, into which the glass is slid, after the
manner of a sliding box lid. In the end of the third week in July the
box was placed in the kitchen garden under the shadow of a high north
wall; it was then about half filled with good turfy loam, to which had
been added a little leaf mould and a good sprinkling of sharp sand. The
soil was then pressed down very firmly (the box being nearly half full
when pressed), and then thoroughly well soaked with rain water, and
allowed to stay uncovered until the next day. The next day good stout
cuttings were taken of all the roses, both tea and hybrid perpetual,
which it was desired to add to the stock. They were then inserted
closely and firmly in the soil, just over the bottom leaf, the glasses
were slipped on and puttied down; the grooves in which the glass slid,
and even the joints in the glass, being filled with putty, so as to
exclude the air. The whole thing completed, nothing more remained to be
done but to leave the box in its cool, shady nook for five or six weeks,
when the growing points of the free starting kinds gave notice that the
glasses might be removed, a bit at a time, with safety. Nothing could be
more simple, or demand less skill, and the operation may be carried out
successfully by an amateur at any time during the season, when good firm
cuttings can be got, and when six weeks' tolerably fine weather may be
counted on. The success of the whole thing depends on having the glasses
fixed so that they may not be removed until the cuttings are rooted, and
in placing the boxes in a shady place. So treated, carnations and many
of our shrubs and herbaceous perennials may be propagated by unskilled
persons with certainty, and without much trouble.
* * * * *
A FEW OF THE BEST INULAS.
Of the fifty-six species of Inula described in scientific works,
probably not more than thirty are at present in cultivation in
this country, and those are chiefly confined to botanic gardens,
notwithstanding the fact that many of them are useful garden plants.
They are principally distributed throughout Southern Europe, although we
find them extending to Siberia and the Himalayas; indeed, it is to the
Himalayas we are indebted for the kinds that are most ornamental. Some
of the low-growing species are extremely useful for the rockery, such
as I. montana (the Mountain Inula), a fine dwarf plant with woolly
lanceolate leaves and dense heads of orange-colored flowers, resembling
in habit and general appearance some of the creeping Hieraciums. It is a
handsome and desirable plant for the decoration of old walls and similar
places, where it can be a little sheltered from rain and drip. Another
very useful species for this purpose is I. rhizocephaloides, found
plentifully in the Himalayas. It is one of the prettiest Alpine
composites we have. It seldom attains more than from one inch to two
inches in height, forming a dense rosette of short, hairy, oval leaves,
in the center of which the bright purple involucres, in the form of a
ball, are extremely interesting. It is easily cultivated, requiring,
however, a rather snug nook, where it will not be allowed to become too
dry. It is best propagated from seed. Then there is the woolly Inula (I.
candida), a pretty plant with small oval leaves, covered with a thick,
silky down, and much in the way of the white-leaved I. limonifolia, both
of which are very effective when grown in masses, which should always
be low down near the front of a rockery, or as an edging for a mixed
border. The glandular-leaved Inula (I. glandulosa), of which a good
representation is here given, is a beautiful hardy perennial. It is a
native of Georgia and the Caucasian Alps, near the Caspian Sea. It is
a rather robust-growing species, with large, bright, orange-yellow
flowers, varying from three to five inches in diameter, the narrow and
very straggly ray florets contrasting nicely with the rather prominent
disk. The leaves, although quite entire, seem notched, owing to large
black glands which form on their margins. They are lanceolate, and clasp
the stem. The plant is very variable, both as regards robustness and
size of flowers, and this may in a measure account for the confusion
existing between it and I. Oculus-Christi.
The soil most suitable for the full development of I. glandulosa is a
strong, clayey, retentive loam; it does not thrive well in the light
shallow soils in the neighborhood of London, except in shady positions.
I. Hookeri is a free-flowering perennial, with pointed lanceolate
leaves, of a delicate texture, bright green, and very finely toothed.
The flowers, which are sweet-scented, are not so large as those of I.
glandulosa, and are produced singly, the ray florets being, however,
much more numerous, rarely numbering less than thirty. It is found in
abundance in rocky places in Sikkim, where it replaces the nearly allied
I. grandiflora, a dwarfer species, with much shorter, shining leaves;
both are very desirable plants either for rockery or flower border work.
The Elecampane (I. Helenium) is an imposing, robust-growing species,
having large, broad leaves a foot or more in length. It grows from four
feet to five feet in height, and its thick, shaggy branches are crowned
with large yellow flowers. For isolating in woods this plant, is very
useful, and with the exception of Telekia cordifolia, it would be hard
to find a rival to it. It is, I believe, pretty extensively used for
planting in shrubberies, but unless they are thin and open it is seldom
seen to advantage. It is found wild or naturalized in some parts of
England. It flowers in June and July, and even into August when the
season has been favorable.
[Illustration: INULA GLANDULOSA (_flowers deep yellow_.)]
For naturalizing in woods the following will be found useful, _viz_., I.
salicina, I. Oculus-Christi, I. squarrosa, I. britannica, and many more,
the true beauty of which can only be realized in this way. With the
exception of I. rhizocepbaloides, they are all propagated by division
with the greatest ease, or by seed, which is best sown as soon as it is
ripe.--_D.K., The Garden_.
* * * * *
FRUIT GROWING.
By P.H. FOSTER.
In the first place, if you contemplate appropriating a portion of your
land for the raising of fruits, you should have the orchard so situated
that no large animals can run at large on the grounds. Prepare your soil
in the most thorough manner; underdrain, if necessary, to carry off
surplus water; dig deep, large holes; fill in the bottom with debris;
in the very bottom put a few leaves, clam and oyster shells, etc., then
sods; above and below the roots put a good garden or field soil; do not
give the trees fresh manure at the time of setting, but the following
fall manure highly with any kind on top of the ground; dig it in the
following spring; keep the soil frequently worked during the summer,
and, if convenient, mulch with hay, straw, or leaves.
Now you are on the road to progress, provided you have made no mistake
in the selection of your trees. The purposes for which you intend your
fruit is highly important. You should well consider at the outset if
for family or market use. This is a business which requires a long look
ahead, for it is said, "He who plants pears looks ahead for his heirs."
Caution should be used in procuring your stock; little should be planted
that is not fairly tested on the Island, purchased of parties who can be
fully relied upon to give you what you want. Do not buy your stock of
parties who carry labels in their pockets to make to order what you want
out of the same bundle of trees.
Now, having your trees set out in a proper manner, of such varieties
as you desire, the next important step is to bring the trees into
usefulness. My plan is to use bone--fine bone--very freely about every
three years. Another important matter is that of trimming. "Fire
purifies," and the knife regulates the grand balance or equilibrium
between roots and tops. In most cases the top outgrows the roots, the
consequence of which is an ultimate weakness of the tree. It is thrown
into excessive fruiting, disease, and premature decay. To avoid this
result, use the knife when required. Thin out the inside branches when
small, and if the tree does not make a satisfactory growth, cut back
half way to the ground.
We will suppose that you have got your trees growing nicely, and they
have begun to bear fruit. There are other important steps to be taken,
which will be of little cost to you. Provide a wind-break for the
orchard. Evergreens answer the purpose, being a protection against the
wind. Having this matter attended to, there are other enemies with which
we must contend. I refer to the apple and peach tree borers. The former
will live in the tree for three years, if unmolested; the latter, one
year only. They are very easily destroyed by looking over the trees and
taking them out with a knife; or maybe prevented from touching the trees
by wrapping a piece of felt paper, 8 inches wide, around the tree near
the ground, the bottom being covered with dirt and the top tied tightly
above. The pear is not generally disturbed by these insects--only the
apple, peach, and quince. We have another insect very destructive to the
plum, peach, cherry, and apple--the _curcutio_, or plum weavel. This
season for the first time in twenty years we have gathered a small
crop of that very desirable plum, the Purple Favorite. We simply threw
air-slaked lime over the trees nearly every morning for from four to six
weeks, from the time the tree was out of bloom. Peach trees should be
treated in the same manner. Another method of fighting this insect is to
spread a sheet under the tree, and with a blow jar off the little Turk
and secure him on the sheet. But I consider the lime procedure the less
trouble and more effective. The tent caterpillar, which is easily seen,
should be destroyed at once. We have yet another insect to contend with
which infests the apple and pear, commonly called the Coddling Moth,
and the larva, the apple-worm (_Garpocapsa pomonella_). The loss by the
ravaaes of this insect alone to the fruit growers of the United States
fan hardly be estimated, as in many cases the whole crop is rendered
worthless. Such a vast destruction of two of the most valuable fruits
the world produces should stimulate scientists in this age of progress
to discover an effectual remedy against such a gigantic evil.
I have never yet discovered nor tried an effectual remedy against this
insect. The nearest I have approached his extermination is in the
following manner: After it has entered the fruit and accomplished its
damage, the time arrives when it has to leave the fruit and hide itself
in a quiet, secure position to undergo the transition from the larva to
the pupa state, which requires, in the early part of the season, eight
or ten days; after this time the miller is hatched and is again ready to
besiege the fruit with its sting. The insect, being two-brooded in this
climate at least, if not disturbed, has an aggregating force to do
mischief the second time. The progeny for the succeeding year have alone
to depend on the security of this second generation of larvae. As they
may often be found in bark of apple trees during winter, my plan of
destruction is, about the first of July to take woolen rags long enough
to wrap around the trees, and say four inches wide. Each week I look
over the trees, and destroy the worms secreted under the rags and
wherever I find them until the fruit is off the trees. I have all the
green fruit, of every kind, carefully picked up as soon as it falls,
thereby destroying many of the curculio as well as the apple-worms.
One word upon the grape--the insect part of the question. The
_Phylloxera vastatrix_, or grape-vine louse, is already at work on Long
Island. It is found very difficult to raise many of our fine, new grapes
with us in consequence of the depredations of this very minute insect,
it being almost too small to be seen by the naked eye. There has lately
been discovered a remedy which is entirely chemical and as yet but
little disseminated. Very soon, no doubt, a discovery will be made that
will stay the progress of this destructive enemy.
We should plant aplenty of cherry and small fruit trees to yield feed
for birds. In return they will assist us in our efforts to preserve a
bountiful supply of this health producing element.
* * * * *
COARSE FOOD FOR PIGS.
A recent subscriber wants advice how to feed pigs of 25 to 35 pounds
weight, that are to be kept over winter and fitted for sale at about six
months old--whether coarse food will not help them as much in winter as
in summer. How roots and pumpkins will answer in lieu of grass, and what
can be fed when this green food is gone? He has had poor success in
growing young pigs on corn alone. He has a reasonably warm pen for
winter.
The question of food is constantly recurring, and this is one of the
best evidences of the advancement of the country in the feeder's
art. When people are making no inquiry as to improved methods in any
direction, no progress can be made. There has been more progress made
in the philosophy of feeding during the last thirty years than in the
century and a half previous.
In pig feeding in the dairy districts, young pigs generally grow up in
a very healthy condition, owing to the refuse milk of the dairy, which
furnishes the principal food of young pigs. Skim-milk contains all the
elements for growing the muscles and bones of young pigs. This gave them
a good, rangy frame, and, when desired, could be fed into 400 or 500
pounds weight. But the fault attending this feeding was, that it was too
scanty to produce such rapid growth as is desired. It took too long to
develop them for the best profit. It had not then been discovered by the
farmer that it costs less to put the first hundred pounds on the pig
than the second, and less for the second than the third, etc.; that it
was much cheaper to produce 200 pounds of pork in six months than in
nine and twelve months. When it became evident that profit required more
rapid feeding, then they began to ply them continually with the most
concentrated food--corn meal or clear corn. If this was fed in summer,
on pasture, no harm was observed, for the grass gave bulk in the
stomach, and the pigs were were healthy and made good progress. But if
the young pigs were fed in pen in winter upon corn meal or clear corn,
the result was quite different; this concentrated food produced feverish
symptoms, and the pigs would lose their appetite for a few days,
drinking only water, which, after a while, would relieve the stomach,
and the pigs would eat vigorously again. Now, had they been fed a few
quarts of turnips, carrots, beets, or pumpkins, to give bulk to the
stomach, and separate the concentrated food, no harm would have come.
This gives the gastric juice a free circulation through the contents of
the stomach, the food is properly digested and applied to the needs of
the body instead of causing fever by remaining in the stomach.--_Live
Stock Journal_.
* * * * *
METE KINGI.
Our engraving is a portrait of a familiar character in New Zealand,
chief Mete Kingi, who recently died at the age of one hundred years.
He was a fine specimen of the Maori race, the native New Zealanders, a
branch of the Malayo-Polynesian family. The New Zealanders surpassed
all other people in the art of tattooing, to which their chiefs gave
especial attention. Mete Kingi, as our picture shows, was no exception.
Tattooing on the face they termed _moko_. The men tattoo their faces,
hips, and thighs; the women their upper lips; for this purpose charcoal
made from kauri gum is chiefly used. It has the blue color when pricked
into the skin, growing lighter in shade in the course of years. The
subject of our illustration embraced Christianity, and was much
respected. Our engraving is from the _Illustrated Australian News_.
[Illustration: THE LATE MAORI CHIEF METE KINGI.]
* * * * *
LAKE TAHOE.
Some very interesting information by Prof. John Le Conte, is given in
the _Overland Monthly_, being the result of some physical observations
made by the author at Lake Tahoe, in 1873. Lake Tahoe, also called Lake
Bigler, is situated at an altitude of 6,247 feet in the Sierra Nevada
Mountains, partly in California, partly in Nevada. The lake has a length
of 22 and a width of 12 miles. As regards its origin, the author regards
it as a "plication hollow," or a trough produced by the formation of two
mountain ridges, afterward modified by glacial agency. The depth of the
lake is remarkable; the observations taken at ten stations along the
length of the lake gave the following depths in feet: 900, 1,385, 1,495,
1,500, 1,506, 1,540, 1,504, 1,600, 1,640, 1645. This depth exceeds that
of the Swiss lakes proper--Lake Geneva, for example, has a maximum depth
of 1,096 feet--but is considerably less than that of Lakes Maggiore and
Como, on the Italian side of the Alps. A series of observations of the
temperature of the water were taken between the 11th and 18th of August.
The average corrected results are as follows:
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