Scientific American Supplement, No. 586, March 26, 1887 by Various
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Various >> Scientific American Supplement, No. 586, March 26, 1887
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[Illustration: FIGS. 9 TO 16.--VARIOUS PYROTECHNIC DEVICES.]
[Illustration: FIGS. 17.--ILLUMINATING ROCKET.]
A _tarred fascine_ consists of a small fagot of dry wood, 20 inches in
length by 4 in diameter, covered with the same composition as the preceding
(Fig. 11). Fascines thus prepared burn for about half an hour. They are
placed upright in supports, and these latter are located at intervals of
twenty yards.
The _Lamarre compositions_ are all formed of a combustible substance, such
as boiled oil,[1] of a substance that burns, such as chlorate of potash,
and of various coloring salts.
[Footnote 1: For preparation see page 9304 of SUPPLEMENT.]
The _white composition_ used for charging fire balls and 11/2 inch flambeaux
is formed of 500 parts of powdered chlorate of potash, 1,500 of nitrate of
baryta, 120 of light wood charcoal, and 250 of boiled oil. Another white
composition, used for charging 3/4 inch flambeaux, consists of 1,000 parts of
chlorate of potash, 1,000 of nitrate of baryta, and 175 of boiled oil.
The _red composition_ used for making red flambeaux and percussion signals
consists of 1,800 parts of chlorate of potash, 300 of oxalate of strontia,
300 of carbonate of strontia, 48 of whitewood charcoal, 240 of boiled oil,
6 of oil, and 14 of gum lac.
A red or white _Lamarre flambeau_ consists of a sheet rubber tube filled
with one of the above-named compositions. The lower extremity of this tube
is closed with a cork. When the charging has been effected, the flambeau is
primed by inserting a quickmatch in the composition. This is simply lighted
with a match or a live coal. The composition of the Lamarre quickmatch will
be given hereafter.
A Lamarre flambeau 11/2 inch in diameter and 3 inches in length will burn for
about thirty-five minutes. One of the same length, and 3/4 inch in diameter,
lasts but a quarter of an hour.
A _fire ball_ consists of an open work sack internally strengthened with a
sheet iron shell, and fitted with the Lamarre white composition. After the
charging has been done, the sphere is wound with string, which is made to
adhere by means of tar, and canvas is then wrapped around the whole.
Projectiles of this kind, which have diameters of 6, 8, 11, and 13 inches,
are shot from mortars.
The _illuminating grenade_ (Fig. 13) consists of a sphere of vulcanized
rubber, two inches in diameter, charged with the Lamarre white composition.
The sphere contains an aperture to allow of the insertion of a fuse. The
priming is effected by means of a tin tube filled with a composition
consisting of three parts of priming powder, two of sulphur, and one of
saltpeter. These grenades are thrown either by hand or with a sling, and
they may likewise be shot from mortars. Each of these projectiles
illuminates a circle thirty feet in diameter for a space of time that
varies, according to the wind, from sixty to eighty seconds.
The _percussion signal_ (Fig. 14) consists of a cylinder of zinc, one inch
in diameter and one and a quarter inch in length, filled with Lamarre red
composition. It is provided with a wooden handle, and the fuse consists of
a capsule which is exploded by striking it against some rough object. This
signal burns for nearly a minute.
_Belgian illuminating balls and cylinders_ are canvas bags filled with
certain compositions. The cylinders, five inches in diameter and seven in
length, are charged with a mixture of six parts of sulphur, two of priming
powder, one of antimony, and two of beeswax cut up into thin slices. They
are primed with a quickmatch. The balls, one and a half inch in diameter,
are charged with a composition consisting of twelve parts of saltpeter,
eight of sulphur, four of priming powder, two of sawdust, two of beeswax,
and two of tallow. They are thrown by hand. They burn for six minutes.
_Illuminating kegs_ (Fig. 15) consist of powder kegs filled with shavings
covered with pitch. An aperture two or three inches in diameter is made in
each head, and then a large number of holes, half an inch in diameter, and
arranged quincuncially, are bored in the staves and heads. All these
apertures are filled with port-fires.
The _illuminating rocket_ (Fig. 17) consists of a sheet iron cartridge,
_a_, containing a composition designed to give it motion, of a cylinder,
_b_, of sheet iron, capped with a cone of the same material and containing
illuminating stars of Lamarre composition and an explosive for expelling
them, and, finally, of a directing stick, _c_. Priming is effected by means
of a bunch of quickmatches inclosed in a cardboard tube placed in contact
with the propelling composition. This latter is the same as that used in
signal rockets. As in the case of the latter, a space is left in the axis
of the cartridges. These rockets are fired from a trough placed at an
inclination of fifty or sixty degrees. Those of three inches illuminate the
earth for a distance of 900 yards. They may be used to advantage in the
operation of signaling.
A _parachute fire_ is a device designed to be ejected from a pot at the end
of the rocket's travel, and to emit a bright light during its slow descent.
It consists of a small cylindrical cardboard box (Fig. 16) filled with
common star paste or Lamarre stars, and attached to a parachute, _e_, by
means of a small brass chain, _d_.
To make this parachute, we cut a circle ten feet in diameter out of a piece
of calico, and divide its circumference into ten or twelve equal parts. At
each point of division we attach a piece of fine hempen cord about three
feet in length, and connect these cords with each other, as well as with
the suspension chain, by ligatures that are protected against the fire by
means of balls of sized paper.
In rockets designed to receive these parachutes, a small cavity is reserved
at the extremity of the cartridge for the reception of 225 grains of
powder. To fill the pot, the chain, _d_, is rolled spirally around the box,
_c_, and the latter is covered with the parachute, _e_, which has been
folded in plaits, and then folded lengthwise alternately in one direction
and the other.
The _parachute port-fire_ consists of a cardboard tube of from quarter to
half an inch in diameter, and from four to five inches in length, closed at
one extremity and filled with star paste. This is connected by a brass wire
with a cotton parachute eight inches in diameter. A rocket pot is capable
of holding twenty of these port-fires.
Parachute fires and port-fires are used to advantage in the operation of
signaling.--_La Nature_.
* * * * *
IMPROVEMENT IN LAYING OUT FRAMES OF VESSELS--THE FRAME TRACER.
By GUSTAVE SONNENBURG.
To avoid the long and time-consuming laying out of a boat by ordinates and
abscissas, I have constructed a handy apparatus, by which it is possible
without much trouble to obtain the sections of a vessel graphically and
sufficiently accurate. The description of its construction is given with
reference to the accompanying cut. A is a wooden rod of rectangular
section, to which are adapted two brackets, a_{1} a_{2}, lined with India
rubber or leather; a_{1} is fixed to the wood, a_{2} is of metal, and, like
the movable block of a slide gauge, moves along A. In the same plane is a
second rod, perpendicular to A, and attached thereto, which is perforated
by a number of holes. A revolving pin, C, is adapted to pass through these
holes, to which a socket, D, is pivoted, C acting as its axis. To prevent
this pin from falling out, it is secured by a nut behind the rod. Through
the socket, D, runs a rod, E, which carries the guide point, s_{1}, and
pencil, s_{2}. Over s_{1} a rubber band is stretched, to prevent injury to
the varnish of the boat. Back of and to A and B a drawing board is
attached, over which a sheet of paper is stretched.
[Illustration: THE FRAME TRACER.]
The method of obtaining a section line is as follows: The rod, A, is placed
across the gunwale and perpendicular to the axis of the boat, and its
anterior vertical face is adjusted to each frame of the boat which it is
desired to reproduce. By means of the brackets, a_{1} and a_{2}, A is fixed
in place. The bolt, C, is now placed in the perforations already alluded
to, which are recognized as most available for producing the constructional
diagram. At the same time the position of the pencil point, s_{2}, must be
chosen for obtaining the best results.
Next the operator moves along the side of the boat the sharpened end,
s_{1}, of the rod, E, and thus for the curve from keel to gunwale, s_{2}
describes a construction line. It is at once evident that a_{2}, for
example, corresponds to the point, a_{1}. The apparatus is now removed and
placed on the working floor. If, reversing things, the point, s_{1}, is
carried around the construction curve, the point, s_{2}, will inscribe the
desired section in its natural dimensions. This operation is best conducted
after one has chosen and described all the construction curves of the
boat. Next, the different section lines are determined, one by one, by the
reversed method above described. The result is a half section of the boat;
the other symmetrical half is easily obtained.
If the whole process is repeated for the other side of the boat, tracing
paper being used instead of drawing paper, the boat may be tested for
symmetry of building, a good control for the value of the ship. For
measuring boats, as for clubs and regattas, for seamen, and often for the
so-called _Spranzen_ (copying) of English models, my apparatus, I doubt
not, will be very useful.--_Neuste Erfindungen und Erfahrungen_.
* * * * *
TAR FOR FIRING RETORTS.
The attention of gas engineers has been forcibly directed to the use of tar
as a fuel for the firing of retorts, now that this once high-priced
material is suffering, like everything else (but, perhaps, to a more marked
extent), by what is called "depression in trade." In fact, it has in many
places reached so low a commercial value that it is profitable to burn it
as a fuel. Happily, this is not the case at Nottingham; and our interest in
tar as a fuel is more experimental, in view of what may happen if a further
fall in tar products sets in. I have abandoned the use of steam injection
for our experimental tar fires in favor of another system. The steam
injectors produce excellent heats, but are rather intermittent in their
action, and the steam they require is a serious item, and not always
available.
[Illustration]
Tar being a _pseudo_ liquid fuel, in arranging for its combustion one has
to provide for the 20 to 25 per cent. of solid carbon which it contains,
and which is deposited in the furnace as a kind of coke or breeze on the
distillation of the volatile portions, which are much more easily consumed
than the tar coke.
THE TAR FIRE
I have adopted is one that can be readily adapted to an ordinary coke
furnace, and be as readily removed, leaving the furnace as before. The
diagram conveys some idea of the method adopted. An iron frame, d, standing
on legs on the floor just in front of the furnace door, carries three fire
tiles on iron bearers. The top one, a, is not moved, and serves to shield
the upper face of the tile, b, from the fierce heat radiated from the
furnace, and also causes the air that rushes into the furnace between the
tiles, a and b, to travel over the upper face of the tile, b, on which the
tar flows, thereby keeping it cool, and preventing the tar from bursting
into flame until it reaches the edge of the tile, b, over the whole edge of
which it is made to run fairly well by a distributing arrangement. A rapid
combustion takes place here, but some unconsumed tar falls on to the bed
below. About one-third of the grate area is filled up by a fire tile, and
on this the tar coke falls. The tile, c, is moved away from time to time,
and the tar coke that accumulates in front of it is pushed back on to the
fire bars, e, at the back of the furnace, to be there consumed. Air is thus
admitted, by three narrow slot-like openings, to the front of the furnace
between the tiles, a, b, and c, and under c and through the fire bars, e.
The air openings below are about three times the area of the openings in
the front of the furnace; but as the openings between the fire bars and the
tiles are always more or less covered by tar coke, it is impossible to say
what the effective openings are. This disposition answers admirably, and
requires little attention. Three minutes per hour per fire seems to be the
average, and the labor is of a very light kind, consisting of clearing the
passages between the tiles, and occasionally pushing back the coke on to
the fire bars. These latter are not interfered with, and will not require
cleaning unless any bricks in the furnace have been melted, when a bed of
slag will be found on them.
THE AMOUNT OF DRAUGHT
required for these fires is very small, and less than with coke firing. I
find that 0.08 in. vacuum is sufficient with tar fires, and 0.25 in. for
coke fires. The fires would require less attention with more draught and
larger tar supply, as the apertures do not so easily close with a sharp
draught, and the tar is better carried forward into the furnace. A regular
feed of tar is required, and considerable difficulty seems to have been
experienced in obtaining this. So long as we employed ordinary forms of
taps or valves, so long (even with filtration) did we experience
difficulties with the flow of viscous tar. But on the construction of
valves specially designed for the regulation of its flow, the difficulty
immediately disappeared, and there is no longer the slightest trouble on
this account. The labor connected with the feeding of furnaces with coke
and cleaning fires from clinker is of a very arduous and heavy nature.
Eight coke fires are normally considered to be work for one man. A lad
could work sixteen of these tar fires.
COMPOSITION OF FURNACE GASES.
Considerable attention has been paid to the composition of the furnace
gases from the tar fires. The slightest deficiency in the air supply, of
course, results in the immediate production of smoke, so that the damper
must be set to provide always a sufficient air supply. Under these
circumstances of damper, the following analyses of combustion gases from
tar fires have been obtained:
No Smoke.
CO_{2}. O. CO.
11.7 5.0 Not determined.
13.3 3.7 "
10.8 5.4 "
14.8 2.5 "
13.5 3.0 "
12.4 5.6 "
12.4 4.6 "
13.1 5.9 "
15.3 1.0 "
10.8 4.0 "
14.0 2.8 "
______ ______
Average 12.9 3.9
(11 analyses) ______ ______
11.5 Not determined.
14.3 "
14.6 "
Damper adjusted so that a slight smoke was observable in the combustion
gases.
CO_{2}. O. CO.
17.30 None. Not determined.
16.60 " "
16.50 0.1 "
15.80 0.1 "
16.20 1.8 0.7
_______ _____ _____
Average 16.48 0.4 0.7
--_Gas Engineer_.
* * * * *
A NEW MERCURY PUMP.
The mercury pumps now in use, whether those of Geissler, Alvergniat,
Toepler, or Sprengel, although possessed of considerable advantages, have
also serious defects. For instance, Geissler's pump requires a considerable
number of taps, that of Alvergniat and Toepler is very fragile in
consequence of its complicated system of tubes connected together, and that
of Sprengel is only suitable for certain purposes.
The new mercury pump constructed by Messrs. Greisser and Friedrichs, at
Stutzerbach, is remarkable for simplicity of construction and for the ease
with which it is manipulated, and also because it enables us to arrive at a
perfect vacuum.
The characteristic of this pump is, according to _La Lumiere Electrique_, a
tap of peculiar construction. It has two tubes placed obliquely in respect
to its axis, which, when we turn this tap 90 or 180 degrees, are brought
opposite one of the three openings in the body of the tap.
Thus the striae that are formed between the hollowed-out parts of the tap do
not affect its tightness; and, besides, the turns of the tap have for their
principal positions 90 and 180 degrees, instead of 45 and 90 degrees, as in
Geissler's pump.
The working of the apparatus, which only requires the manipulation of a
single tap, is very simple. When the mercury is raised, the tap is turned
in such a manner that the surplus of the liquid can pass into the enlarged
appendage, a, placed above the tap, and communication is then cut off by
turning the tap to 90 degrees.
The mercury reservoir having descended, the bulb empties itself, and then
the tap is turned on again, in order to establish communication with the
exhausting tube. The tap is then closed, the mercury ascends again, and
this action keeps on repeating.
[Illustration]
* * * * *
NO ELECTRICITY FROM THE CONDENSATION OF VAPOR.--It has been maintained by
Palmieri and others that the condensation of vapor results in the
production of an electrical charge. Herr S. Kalischer has renewed his
investigations upon this point, and believes that he has proved that no
electricity results from such condensation. Atmospheric vapor was condensed
upon a vessel coated with tin foil, filled with ice, carefully insulated,
and connected with a very sensitive electrometer. No evidence could be
obtained of electricity.--_Ann. der Physik und Chemie_.
* * * * *
THE ELECTRO-MAGNETIC TELEPHONE TRANSMITTER.
An interesting contribution was made by M. Mercadier in a recent number of
the _Comptes Rendus de l'Academie Francaise_. On the ground of some novel
and some already accepted experimental evidence, M. Mercadier holds that
the mechanism by virtue of which the telephonic diaphragms execute their
movements is analogous to, if not identical with, that by which solid
bodies of any form, a wall for instance, transmit to one of their surfaces
all the vibratory movements of any kind which are produced in the air in
contact with the other surface. It is a phenomenon or resonance. Movements
corresponding to particular sounds may be superposed in slender diaphragms,
but this superposition must necessarily be disturbing under all but
exceptional circumstances. In proof of this view, it is cited that
diaphragms much too rigid, or charged with irregularly distributed masses
over the surface, or pierced with holes, or otherwise evidently unfitted
for the purpose, are available for transmission. They will likewise serve
when feathers, wool, wood, metals, mica, and other substances to the
thickness of four inches are placed between the diaphragm and the source of
vibratory movement. The magnetic field does not alter these relations in
any way. The real diaphragm may be removed altogether. It is sufficient to
replace it by a few grains of iron filings thrown on the pole covered with
a piece of pasteboard or paper. Such a telephone works distinctly although
feebly; but any slender flexible disk, metallic or not, spread over across
the opening of the cover of the instrument, with one or two tenths of a
gramme (three grains) of iron filings, will yield results of increased and
even ordinary intensity. This is the iron filing telephone, which is
reversible; for a given magnetic field there is a certain weight of iron
filings for maximum intensity. It appears thus that the advantage of the
iron diaphragm over iron filings reduces itself to presenting in a certain
volume a much more considerable number of magnetic molecules to the action
of the field. The iron diaphragm increases the telephonic intensity, but it
is by no means indispensable.
* * * * *
ON ELECTRO-DISSOLUTION, AND ITS USE AS REGARDS ANALYSIS.
By H.N. WARREN, Research Analyst.
On the same principle that electro-dissolution is used for the estimation
of combined carbon in steel, etc., I have lately varied the experiment by
introducing, instead of steel, iron containing a certain percentage of
boron, and, having connected the respective boride with the positive pole
of a powerful battery, and to the negative a plate of platinum, using as a
solvent dilute sulphuric acid, I observed, after the lapse of about twelve
hours, the iron had entirely passed into solution, and a considerable
amount of brownish precipitate had collected at the bottom of the vessel,
intercepted by flakes of graphite and carbon; the precipitate, having been
collected on a filter paper, washed, and dried, on examination proved to be
amorphous boron, containing graphite and other impurities, which had become
chemically introduced during the preparation of the boron compound. The
boron was next introduced into a small clay crucible, and intensely heated
in a current of hydrogen gas, for the purpose of rendering it more dense
and destroying its pyrophoric properties, and was lastly introduced into a
combustion tubing, heated to bright redness, and a stream of dry carbonic
anhydride passed over it, in order to separate the carbon, finally pure
boron being obtained.
In like manner silicon-eisen, containing 9 per cent. of silicon, was
treated, but not giving so satisfactory a result. A small quantity only of
silicon separates in the uncombined form, the greater quantity separating
in the form of silica, SiO_{2}, the amorphous silicon so obtained
apparently being more prone to oxidation than the boron so obtained.
Ferrous sulphide was next similarly treated, and gave, after the lapse of a
few hours, a copious blackish precipitation of sulphur, and possessing
properties similar to the sulphur obtained by dissolving sulphides such as
cupric sulphide in dilute nitric acid, in all other respects resembling
common sulphur.
Phosphides of iron, zinc, etc., were next introduced, and gave, besides
carbon and other impurities, a residue containing a large percentage of
phosphorus, which differed from ordinary phosphorus with respect to its
insolubility in carbon disulphide, and which resembled the reaction in the
case with silicon-eisen rather than that of the boron compound, insomuch
that a large quantity of the phosphorus had passed into solution.
A rod of impure copper, containing arsenic, iron, zinc, and other
impurities, was next substituted, using hydrochloric acid as a solvent in
place of sulphuric acid. In the course of a day the copper had entirely
dissolved and precipitated itself on the negative electrode, the impurities
remaining in solution. The copper, after having been washed, dried, and
weighed, gave identical results with regard to percentage with a careful
gravimetric estimation. I have lately used this method, and obtained
excellent results with respect to the analysis of commercial copper,
especially in the estimation of small quantities of arsenic, thus enabling
the experimenter to perform his investigation on a much larger quantity
than when precipitation is resorted to, at the same time avoiding the
precipitated copper carrying down with it the arsenic. I have in this
manner detected arsenic in commercial copper when all other methods have
totally failed. I have also found the above method especially applicable
with respect to the analysis of brass.
With respect to ammoniacal dissolution, which I will briefly mention, a rod
composed of an alloy of copper and silver was experimented upon, the copper
becoming entirely dissolved and precipitating itself on the platinum
electrode, the whole of the silver remaining suspended to the positive
electrode in an aborescent form. Arsenide of zinc was similarly treated,
the arsenic becoming precipitated in like manner on the platinum electrode.
Various other alloys, being experimented upon, gave similar results.
I may also, in the last instance, mention that I have found the above
methods of electro-dissolution peculiarly adapted for the preparation of
unstable compounds such as stannic nitrate, potassic ferrate, ferric
acetate, which are decomposed on the application of heat, and in some
instances have succeeded by the following means of crystallizing the
resulting compound obtained.--_Chem. News_.
* * * * *
A NEWLY DISCOVERED SUBSTANCE IN URINE.
Dr. Leo's researches on sugar in urine are interesting, and tend to correct
the commonly accepted views on the subject. Professor Scheibler, a chemist
well known for his researches on sugar, has observed that the determination
of the quantity of that substance contained in a liquid gives different
results, according as it is done by Trommer's method or with the
polariscope. As sugar nowadays is exclusively dealt with according to the
degree of polarization, this fact is of enormous value in trade. Scheibler
has isolated a substance that is more powerful in that respect than grape
sugar. Dr. Leo's researches yield analogous results, though in a different
field. He has examined a great quantity of diabetic urine after three
different methods, namely, Trommer's (alkaline solution of copper); by
fermentation; and with the polarization apparatus. In many cases the
results agreed, while in others there was a considerable difference.
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