Scientific American Supplement, No. 803, May 23, 1891 written by Various
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Various >> Scientific American Supplement, No. 803, May 23, 1891
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9 [Illustration]
SCIENTIFIC AMERICAN SUPPLEMENT NO. 803
NEW YORK, May 23, 1891
Scientific American Supplement. Vol. XXXI., No. 803.
Scientific American established 1845
Scientific American Supplement, $5 a year.
Scientific American and Supplement, $7 a year.
* * * * *
TABLE OF CONTENTS.
I. ASTRONOMY.--The Great Equatorial of the Paris Observatory.--
The new telescope recently put in use in Paris.--Description of
the instrument and of its effects.--3 illustrations
II. CHEMISTRY.--An Apparatus for Heating Substances in Glass
Tubes under Pressure.--By H. PEMBERTON, Jr.--A simple apparatus
for effecting this purpose, avoiding risk of personal injury.--
2 illustrations
Table of Atomic Weights.--A revised table of atomic weights,
giving the results of the last determinations, and designed for
every-day use
Testing Cement.--A laboratory process for testing Portland cement
III. CIVIL ENGINEERING.--The Compressed Air System of Paris.
--An elaborate review of this great installation for the transmission
of power.--The new compressed air station, with full details
of performances of apparatus, etc.--10 illustrations
IV. ENTOMOLOGY.--Report on Insects.--Continuation of this report
on noxious insects.--Their habits and how to cope with them.
--18 illustrations
V. FLORICULTURE.--Lily of the Valley.--Practical notes on the
cultivation of this popular flower.--How to raise it and force the
growth
VI. MATHEMATICS.--The Conic Sections.--By Prof. C.W.
MACCORD.--Examination of the four conic sections with a general
definition applicable to all.--6 illustrations
VII. MECHANICAL ENGINEERING.--The Builders of the Steam
Engine--The Founders of Modern Industries and Nations.--By Dr.
R.H. THURSTON.--Prof. Thurston's address before the Centennial
Celebration of the American Patent System at Washington,
D.C.--The early history of the steam engine and its present position
in the world
VIII. MISCELLANEOUS.--The Breeds of Dogs.--Popular description
of the different breeds of dogs most affected by amateurs.--6
illustrations
IX. NAVAL ENGINEERING.--Modern Armor.--By F.R. BRAINARD.--The
development of modern ship armor, from laminated
sandwiched and compound types to the present solid armor.--9
illustrations
X. PISCICULTURE.--Restocking the Seine with Fish.--The introduction
of 40,000 fry of California trout and salmon, designed to restock
the Seine, depopulated of fish by explosions of dynamite
used in breaking up the ice.--1 illustration
XI. RAILWAY ENGINEERING.--Improved Hand Car.--A novelty
in the construction of hand cars, avoiding the production of a
dead center.--1 illustration
XII. TECHNOLOGY.--The Tanning Materials of Europe.--The natural
tanning materials and pathological or abnormal growth tanning
materials described and classified, with relative power
* * * * *
THE GREAT EQUATORIAL OF THE PARIS OBSERVATORY.
The great instrument which has just completed the installation of our
national observatory is constructed upon the same principle as the
elbowed equatorial, 11 in. in diameter, established in 1882, according
to the ingenious arrangement devised as long ago as 1872, by Mr.
Loewy, assistant director of the Paris Observatory.
We shall here recall the fact that the elbowed equatorial consists of
two parts joined at right angles. One of these is directed according
to the axis of the world, and is capable of revolving around its own
axis, and the other, which is at right angles to it, is capable of
describing around the first a plane representing the celestial
equator. At the apex of the right angle there is a plane mirror of
silvered glass inclined at an angle of 45 deg. with respect to the
optical axis, and which sends toward the ocular the image coming from
the objective and already reflected by another and similar plane
mirror. The objective and this second mirror (which is inclined at an
angle of 45 deg.) are placed at the extremity of the external part of
the tube, and form part of a cube, movable around the axis of the
instrument at right angles with the axis of the world. The diagram in
Fig. 3 will allow the course of a luminous ray coming from space to be
easily understood. The image of the star, A, toward which the
instrument is directed, traverses the objective, B C, is reflected
first from the mirror, B D, and next from the central mirror, E F, and
finally reaches O, at the ocular where the observer is stationed.
This new equatorial differs from the first model by its much larger
dimensions and its extremely remarkable mechanical improvements. The
optical part, which is admirably elaborated, consists of a large
astronomical objective 24 in. in diameter, and of a photographic
objective of the same aperture, capable of being substituted, one for
the other, according to the nature of the work that it is desired to
accomplish by the aid of this colossal telescope, the total length of
which is 59 ft. The two plane mirrors which complete the optical
system have, respectively, diameters of 34 in. and 29 in. These two
magnificent objectives and the two mirrors were constructed by the
Brothers Henry, whose double reputation as astronomers and opticians
is so universally established. The mechanical part is the successful
work of Mr. Gautier, who has looked after every detail with the
greatest care, and has thus realized a true _chef d'oeuvre_. The
colossal instrument, the total weight of which is 26,400 lb., is
maneuvered by hand with the greatest ease. A clockwork movement, due
to the same able manufacturer, is capable, besides, of moving the
instrument with all the precision desirable, and of permitting it to
follow the stars in their travel across the heavens. A star appearing
in the horizon can thus be observed from its rising to its setting.
The astronomer, his eye at the ocular, is always conveniently seated
at the same place, observing the distant worlds, rendered immovable,
so to speak, in the field of the instrument. For stars which, like the
moon and the planets, have a course different from the diurnal motion,
it is possible to modify the running of the clockwork, so that they
can thus be as easily followed as in the preceding case. Fig. 1 gives
a general view of the new installation, for which it became necessary
to build a special edifice 65 ft. in height on the ground south of the
observatory bordering on the Arago Boulevard. A large movable
structure serves for covering the external part of the instrument.
This structure rests on rails, upon which it slides toward the south
when it is desired to make observations. It will be seen from the
figure how the principal axis of the instrument rests upon the two
masonry pillars, one of which is 49 ft. and the other 13 ft. in
height.
[Illustration: FIG 1.--THE GREAT EQUATORIAL OF THE PARIS OBSERVATORY.]
The total cost of the pavilion, rolling structure, and instrument
(including the two objectives) will amount to about $80,000 after the
new equatorial has been provided with the scientific apparatus that
necessarily have to accompany it for the various and numerous
applications to which the use of it will give rise.
[Illustration: FIG 2.--OCULAR OF THE GREAT EQUATORIAL.]
Fig. 2 shows us the room in the observatory in which the astronomer,
seated in his chair, is completely protected against the inclemencies
of the weather. Here, with his eye applied to the ocular, he can,
without changing position (owing to all the handles that act at his
will upon the many transmissions necessary for the maneuvering),
direct his instrument unaided toward every point of the heavens with
wonderful sureness and precision. The observer has before him on the
same plane two divided circles, one of which gives the right
ascensions and the other the declinations, and which he consults at
each observation for the exact orientation of the equatorial.
[Illustration: FIG. 3.--DIAGRAM SHOWING THE COURSE OF A LUMINOUS RAY
IN THE GREAT EQUATORIAL.]
All the readings are done by the aid of electric lamps of very small
dimensions, supplied by accumulators, and which are lighted at will.
Each of these lamps is of one candle power; two of them are designed
for the reading of the two circles of right ascension and of
declination; a third serves for the reading of the position circle of
the micrometer; two others are employed for the reading of the drums
fixed upon the micrometric screws; four others serve for rendering the
spider threads of the reticule brilliant upon a black ground; and
still another serves for illuminating the field of the instrument
where the same threads remain black upon a luminous ground. The
currents that supply these lamps are brought over two different
circuits, in which are interposed rheostats that permit of graduating
the intensity of the light at will.
Since the installation of the first model of an elbowed equatorial of
11 in. aperture, in 1882, at the Paris Observatory, the numerous and
indisputable advantages of this sort of instrument have led a certain
number of observatories to have similar, but larger, instruments
constructed. In France, the observatories of Alger, Besancon, and
Lyons have telescopes of this kind, the objectives of which have
diameters of from 12 in. to 13 in., and which have been used for
several years past in equatorial observations of all kinds. The Vienna
Observatory has for the last two years been using an instrument of
this kind whose objective has an aperture of 15 inches. Another
equatorial of the same kind, of 16 in. aperture, is now in course of
construction for the Nice Observatory, where it will be especially
employed as a seeker of exceptional power--a role to which this kind
of instrument lends itself admirably. The optical part of all these
instruments was furnished by the Messrs. Henry, and the mechanical
part by Mr. Gautier.
The largest elbowed equatorial is, therefore, that of the Paris
Observatory. Its optical power, moreover, corresponds perfectly to its
huge dimensions. The experimental observations which have already been
made with it fully justify the hopes that we had a right to found upon
the professional skill of the eminent artists to whom we owe this
colossal instrument. The images of the stars were given with the
greatest sharpness, and it was possible to study the details of the
surface of the moon and other planets, and several star clusters, in
all their peculiarities, in the most remarkable manner.
When it shall become possible to make use of this equatorial for
celestial photography, there is no doubt that we shall obtain the most
important results. As regards the moon, in particular, the
photographing of which has already made so great progress, its direct
image at the focus of the large 24 in. photographic objective will
have a diameter of 11 in., and, being magnified, will be capable of
giving images of more than 3 ft. in diameter.--_La Nature_.
* * * * *
LILY OF THE VALLEY.
There is no flower more truly and universally popular than the lily of
the valley. What can be more delicious and refreshing than the scent
of its fragrant flowers? What other plant can equal in spring the
attractiveness of its pillars of pure white bells half hidden in their
beautiful foliage? There are few gardens without a bed of lily of the
valley, but too often the place chosen for it is some dark corner
where nothing else would be expected to grow, but it is supposed as a
matter of course that "it will do for a lily bed." The consequence is
that although these lilies are very easy things to cultivate, as
indeed they ought to be, seeing that they grow wild in the woods of
this and other countries, yet one hears so often from those who take
only a slight interest in practical gardening, "I have a lily bed, but
I scarcely ever get any lilies." Wild lilies are hardly worth the
trouble of gathering, they are so thin and poor; it is interesting to
find a plant so beautiful and precious in the garden growing wild in
the woods, but beyond that the flowers themselves are worth but very
little. This at once tells us an evident fact about the lily of the
valley, viz., that it does require cultivation. It is not a thing to
be left alone in a dark and dreary corner to take care of itself
anyhow year after year. People who treat it so deserve to be
disappointed when in May they go to the lily bed and find plenty of
leaves, but no flowers, or, if any, a few poor, weak attempts at
producing blossoms, which ought to be so beautiful and fragrant.
One great advantage of this lovely spring flower is that it can be so
readily and easily forced. Gardeners in large places usually spend
several pounds in the purchase of crowns and clumps of the lily of the
valley, which they either import direct from foreign nurserymen or
else procure from their own dealer in such things, who imports his
lilies in large quantities from abroad. But we may well ask, Have
foreign gardeners found out some great secret in the cultivation of
this plant? Or is their climate more suitable for it? Or their soil
adapted to growing it and getting it into splendid condition for
forcing? It is impossible that the conditions for growing large and
fine heads of this lily can be in any way better in Berlin or
elsewhere than they are in our own land, unless greater heat in summer
than we experience in England is necessary for ripening the growths in
autumn.
There is another question certainly as to varieties; one variety may
be superior to another, but surely if so it is only on the principle
of the survival of the fittest, that is to say, by carefully working
on the finest forms only and propagating from them, a strong and
vigorous stock may be the result, and this stock may be dignified with
a special name. For my own part what I want is to have a great
abundance of lily of the valley from February till the out-door season
is over. To do this with imported clumps would, of course, be most
costly, and far beyond what any person ought to spend on mere flowers.
Though it must be remembered that it is an immense advantage to the
parish priest to be able to take bright and sweet flowers to the
bedside of the sick, or to gratify the weary spirit of a confirmed
invalid, confined through all the lovely spring time to the narrow
limits of a dull room, with the fragrant flowers of the lily of the
valley. I determined, therefore, that I would have an abundance of
early lilies, and that they should not be costly, but simply produced
at about the same expense as any other flowers, and I have been very
successful in accomplishing this by very simple means. First of all,
it is necessary to have the means of forcing, that is to say the
required heat, which in my case is obtained from an early vinery. I
have seen lilies forced by pushing the clumps in under the material
for making a hot bed for early cucumbers, the clumps being drawn out,
of course, as soon as the flowers had made a good start. They have
then to be carefully and very gradually exposed to full light, but
often, although fine heads of bloom may be produced in this way, the
leaves will be few and poor.
My method is simply this: In the kitchen garden there is the old
original bed of lilies of the valley in a corner certainly, but not a
dark corner. This is the reservoir, as were, from whence the regular
supply of heads for special cultivation is taken. This large bed is
not neglected and left alone to take care of itself, but carefully
manured with leaf mould and peat moss manure from the stable every
year. Especially the vacant places made by taking out the heads for
cultivation are thus filled up.
Then under the east wall another piece of ground is laid out and
divided into four plots. When I first began to prepare for forcing I
waited four years, and had one plot planted with divided heads each
year. Clumps are taken up from the reserve bed and then shaken out and
the heads separated, each with its little bunch of fibrous roots. They
are then carefully planted in one of the plots about 4 in. or 5 in.
apart, the ground having previously been made as light and rich as
possible with plenty of leaf mould. I think the best time for doing
this is in autumn, after the leaves have turned yellow and have rotted
away; but frequently the operation has been delayed till spring,
without much difference in the result.
Asparagus is usually transplanted in spring, and there is a wonderful
affinity between the two plants, which, of course, belong to the same
order. It was a long time to wait--four years--but I felt there was no
use in being in too great a hurry, and every year the plants
manifestly improved, and the buds swelled up nicely and looked more
plump each winter when the leaves were gone. It must be remembered
also that a nice crop of flowers could be gathered each year. When the
fourth year came, the first plot was divided up into squares about 2
ft. each way, and taken up before any hard frost or snow had made
their appearance, and put away on the floor of an unused stable. From
the stable they are removed as required in the squares to the vinery,
where they grow beautifully, not sending up merely fine heads of bloom
without a vestige of leaf, but growing as they would in spring out of
doors with a mass of foliage, among which one has to search for the
spikes of flower, so precious for all sorts of purposes at that early
season of the year.
The spikes produced in this way do not equal in thickness and
substance of petal the flowers which come from more carefully prepared
clumps imported from Berlin, but they are fine and strong, and above
all most abundant. I can not only supply the house and small vases for
the church, but also send away boxes of the flowers to friends at a
distance, besides the many gifts which can be made to those who are
ill or invalids. Few gifts at such a time are more acceptable than a
fragrant nosegay of lily of the valley. In order to keep the supply of
prepared roots ready year after year, a plot of ground has only to be
planted each autumn, so that in the rotation of years it may be ready
for forcing when its turn shall come.
As the season advances, as every one knows who has attempted to force
the lily of the valley, much less time is taken in bringing the
flowers to perfection under precisely the same circumstances as those
in which the first sods are forced. In February or earlier the buds
are more unwilling to start; there seems to be a natural repugnance
against being so soon forced out of the winter's sleep and rest. But
when the flowers do come, they are nearly as fine and their leaves are
quite as abundant in this way of forcing as from the pieces introduced
much later into heat. It would be easy to preserve the squares after
all the flowers are gathered, but I found that they would not, like
strawberries, kindly furnish forth another crop later on in the year,
and, therefore, mine are flung away; and I have often pitied the
tender leaves in the frost and snow after their short sojourn in the
hot climate of the vinery. But the reserve bed will always supply an
ample quantity of fresh heads, and it is best to take the new plants
for preparation in the kitchen garden from this reserve bed.
This very simple method of forcing lilies of the valley is within the
reach of any one who has even a small garden and a warm house, and
these two things are becoming more and more common among us every
day.--_A Gloucestershire Parson, in The Garden_.
* * * * *
[Continued from SUPPLEMENT, No. 802, page 12820.]
REPORT ON INSECTS.
THE ONION MAGGOT.
_Phorbia ceparum_ (Meig.)
Early in June a somewhat hairy fly, Fig. 9, may be seen flying about,
and depositing its eggs on the leaves of the young onion plants, near
the roots, Fig. 10.
[Illustration: FIG. 9.]
Dr. Fitch describes this fly as follows: "It has a considerable
resemblance to the common house fly, though when the two are placed
side by side, this is observed as being more slender in its form. The
two sexes are readily distinguished from each other by the eyes, which
in the males are close together, and so large as to occupy almost the
whole surface of the head, while in the females they are widely
separated from each other. These flies are of an ash gray color, with
the head silvery, and a rusty black stripe between the eyes, forked at
its hind end. And this species is particularly distinguished by having
a row of black spots along the middle of the abdomen or hind body,
which sometimes run into each other, and then forming a continuous
stripe.
"This row of spots is quite distinct in the male, but in the female is
very faint, or is often wholly imperceptible. This fly measured 0.22
to 0.25 inch in length, the females being usually rather larger than
the males." The eggs are white, smooth, somewhat oval in outline, and
about one twenty-fifth of an inch in length. Usually not more than
half a dozen are laid on a single plant, and the young maggot burrows
downward within the sheath, leaving a streak of pale green to indicate
its path, and making its way into the root, devours all except the
outer skin.
[Illustration: FIG. 10.]
The maggots reach their full growth in about two weeks, when they are
about one-third of an inch long, white and glossy, tapering from the
posterior end to the head, which is armed with a pair of black,
hook-like jaws. The opposite end is cut off obliquely and has eight
tooth-like projections around the edge, and a pair of small brown
tubercles near the middle. Fig. 11 shows the eggs, larva, and pupa,
natural size and enlarged.
[Illustration: FIG. 11.]
They usually leave the onions and transform to pupae within the ground.
The form of the pupa does not differ very much from the maggot, but
the skin has hardened and changed to a chestnut brown color, and they
remain in this stage about two weeks in the summer, when the perfect
flies emerge. There are successive broods during the season, and the
winter is passed in the pupa stage.
The following remedies have been suggested:
Scattering dry, unleached wood ashes over the plants as soon as they
are up, while they are wet with dew, and continuing this as often as
once a week through the month of June, is said to prevent the deposit
of eggs on the plants.
Planting the onions in a new place as remote as possible from where
they were grown the previous year has been found useful, as the flies
are not supposed to migrate very far.
Pulverized gas lime scattered along between the rows has been useful
in keeping the flies away.
Watering with liquid from pig pens collected in a tank provided for
the purpose, was found by Miss Ormerod to be a better preventive than
the gas lime.
When the onions have been attacked and show it by wilting and changing
color, they should either be taken up with a trowel and burned, or
else a little diluted carbolic acid, or kerosene oil, should be
dropped on the infested plants to run down them and destroy the
maggots in the roots and in the soil around them.
Instead of sowing onion seed in rows, they should be grown in hills,
so that the maggots, which are footless, cannot make their way from
one hill to another.
THE CABBAGE BUTTERFLY.
_Pieris rapae_ (Linn.)
In the New England States there are three broods of this insect in a
year, according to Mr. Scudder, the butterflies being on the wing in
May, July, and September; but as the time of the emergence varies, we
see them on the wing continuously through the season.
[Illustration: FIG. 12.]
The expanded wings, Fig. 12, male, measure about two inches, are white
above, with the base dusky. Both sexes have the apex black and a black
spot a little beyond the middle, and the female, Fig. 13, has another
spot below this. The under side of the fore wings is white, yellowish
toward the apex, and with two black spots in both sexes corresponding
to those on the upper side of the female. A little beyond the middle
of the costa, on the hind wings, is an irregular black spot on the
upper surface, while the under surface is pale lemon yellow without
marks, but sprinkled more or less with dark atoms. The body is black
above and white beneath.
[Illustration: FIG. 13.]
The caterpillars of this insect feed on the leaves of cabbage,
cauliflower, turnip, mignonette, and some other plants.
The female lays her eggs on the under side of the leaves of the food
plants, generally, but sometimes on the upper sides or even on the
leaf stalks. They are sugar loaf shaped, flattened at the base, and
with the apex cut off square at the top, pale lemon yellow in color,
about one twenty-fifth of an inch long and one fourth as wide, and
have twelve longitudinal ribs with fine cross lines between them.
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