Scientific American Suppl. No. 299

V >> Various >> Scientific American Suppl. No. 299

Pages:
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10

* * * * *

STEAM FERRY BOATS OF THE PORT OF MARSEILLES.

The small steam ferry boats represented in the accompanying cut are
doing service in the port of Marseilles, and the following description
of them has been given by Mr. Flecher in the _Bulletin de la Societe des
Anciens Eleves d'Arts et Metiers_:

All those who are acquainted with the Old Port of Marseilles know the
inconvenience of communication between one shore and the other, and the
high price of ferriage by row boats. To obviate this, Captain Advient
has been struck with the happy idea of creating a cheap steam service
(fare one cent), thus supplying a genuine want in the modes of
locomotion of the city.

The building of these ferry boats, on a system providing for the use of
separate hulls, was confided to Messrs. Stapfer, De Duclos & Co., of
Marseilles, whose well-known reputation was a sufficient guarantee that
the problem would be successfully solved.

There existed difficulties of two natures: The first of these related to
the stability of boats such as this, having their engine, boiler, supply
of coal, forty passengers who might all occupy one side of the vessel, a
central superstructure, with roof; and, finally, all the weight centered
on five feet of the deck, with nothing below to counterbalance it except
the hollow hulls and two three-foot compartments, each placed toward the
central portion of the hulls and designed as fresh-water reservoirs
for the steam generator. The second difficulty was to obtain the best
utilization possible of a screw placed in the current between the hulls
and upon a shaft inclined toward the stern, that is, "stern" by analogy,
for there is no distinction of fore and aft in ferry boats.

[Illustration: STEAM FERRYBOATS OF THE PORT OF MARSEILLES.]

The conditions of the problem were finally fulfilled to the satisfaction
of all concerned, and especially to that of the public.

The hulls, navicular in form and having a flat bottom, are constructed
of one-tenth inch iron plate and 40x40 angle iron. Their dimensions
are: Length, 33 feet; breadth, 31/4 feet; and depth, 5 feet. The internal
distance between the two shells is 71/4 feet. These hulls, having
absolutely water-tight decks, are connected below by tie bars of flat
iron, and above by vertical stays 1 foot in length, which serve to
support the floor-planks of the deck and boilerplate flooring of the
engine-room. The engine-room, which is 191/2 feet long by 5 feet wide, is
constructed of varnished pitch-pine, with movable side-shutters of teak.
The roof, of thin iron plate, is provided with a ventilator to allow of
the escape of hot air.

The passengers, to the number of forty or fifty, can move about freely
from larboard to starboard, or from stem to stern, or seat themselves
on the benches running along the inside of the guard railing on the two
sides of the vessel. They are protected from rain by a roof, and from
the rays of the sun by a curtain extending along the sides.

Although the usual method of landing is fore and aft, gangways have been
provided at the sides for side-landing should it become necessary.

The general appearance of one of these boats may be likened to that of a
floating street-car. Finally, a small apartment, provided with benches,
is provided for the use of those passengers who might be taken sick, or
for office purposes, if need be.

The total weight of one of the boats is divided up as follows:

Forty passengers................ 6,200 pounds,
Engine and boiler............... 6,600 "
Ballast, water, and equipment... 9,900 "
Deck and superstructure......... 6,600 "
Hull and accessories............12,500 "
______

Total...........................41,800 "

or a displacement of about 700 cubic feet, corresponding to a maximum
draught of 3.7 feet. The mean speed is 4 knots, or 41/2 miles per hour, a
great velocity being unnecessary, owing to the small distance to cross
in a port often obstructed by the general movement of vessels taking
place therein.

The engine is from 16 to 18 horse-power. Its frame is inclined
perpendicularly to the direction of the screw-shaft, the extremity of
which is supported near the screw by a strengthened cross-stay serving
as a pillow-block. The cylinder is 8 inches in diameter, and the piston
has a stroke of 6 inches, causing the screw (which is 31/4 feet diameter)
to make 200 revolutions per minute. The screw, although it has a wide
surface of thrust, gives, nevertheless, a recoil of about 30 per cent.,
because of its location between the hulls and its oblique action on the
shaft.

The steam is furnished by a tubular boiler having an internal fireplace
and a heating surface of sixteen square meters, the draught being
effected by the exhaust of the engine. This boiler, which is tested
up to 14 pounds, is fed by a steam pump, or by a pump actuated by the
engine. The feed pumps take water successively from one or the other of
the reservoirs in the hulls. The reservoirs are filled in the morning,
and their level is ascertained by two small and ingenious Decondun
indicators, the dials of which are placed against the walls of the
engine-room.

Taken altogether, these little boats are well arranged and quite
handsome; and, since they were put into service in June, 1880, they have
proved a great convenience to the hard-working and active population for
which they were built.

* * * * *

OPENING OF A NEW ENGLISH DOCK.

In July last, Admiral the Duke of Edinburgh, with the Naval Reserve
Squadron under his command, arrived in the Firth of Forth and anchored
in Leith Roads. His Royal Highness performed the ceremony of opening the
new dock at Leith, which has been named after him. The "Edinburgh" Dock
at Leith, which was commenced in 1874, consists of a center basin 500
ft. long and 650 ft. wide, and two basins 1,000 ft. long and 200 ft.
wide, separated by a jetty having a width of 250 ft. The total amount
of masonry in the wet docks is 100,000 cubic yards. The north and south
quays are each 1,500 ft. long, and the two sides of the jetty 1,000 ft.
long each, having a total quayage in connection with the dock of 6,775
ft. The walls are 15 ft. thick at the base, narrowing in two tiers to
8 ft. The new dock will cost altogether about L300,000. Leith now
possesses five docks and a total quayage of three miles 808 yards, 1,234
yards of which is the old portion. These works have been constructed, at
a cost of nearly one million sterling, by the Leith Dock Commissioners,
whose chairman, Mr. James Currie, presented an address to the Duke of
Edinburgh, on board the flag-ship H.M.S. Hercules, giving an account of
their affairs. The other docks at Leith are named the "Old Dock," the
"Queen's Dock," the "Victoria," the "Albert," and the "Prince of Wales
Dock." The opening ceremony was arranged to consist of the steamer
Berlin, with his Royal Highness and the Dock Commissioners on board,
accompanied by Sir Donald Currie, M.P., and other gentlemen, passing
through the entrance from the Albert Dock to the new dock, across which
a blue ribbon had been stretched. At the moment when the ribbon snapped
asunder, under the bow of the Berlin, the Duke of Edinburgh, stepping
forward on the upper deck of the steamer, said, "I have now the
gratification of declaring this dock open, and calling it the Edinburgh
Dock." On this announcement being made, a signal was conveyed to a
battery of guns, posted on the sea wall of the new dock, from which a
party of the Royal Artillery fired a Royal salute. The steamer, having
gone round the new dock, was brought up at the quay at the west. His
Royal Highness the Duke of Edinburgh, with Prince Henry of Prussia, the
officers of the fleet, and the Commissioners, disembarked and proceeded
to the saloon in the new dock, where luncheon in honor of the occasion
was given by the Leith Dock Commissioners.--_Illustrated London News,
Aug. 6._

[Illustration: OPENING OF A NEW ENGLISH DOCK.]

* * * * *

IMPROVED GRAIN ELEVATOR.

The illustration shows the apparatus at work transferring a cargo of
grain from the hold of a ship by means of an elevating band fitted
with buckets. By a simple contrivance shown in the engraving by
diamond-shaped squares, the elevating band can be shortened or
lengthened at pleasure, so as to suit it to the position the grain to be
elevated occupies in the ship or barge. When the grain is elevated to
the point whence it is to be transferred to the granary, railway
truck, or other destination, the band travels horizontally on suitable
bearings, the buckets being so constructed that in traveling they retain
their load intact. The contrivance for lengthening and shortening the
bucket band is an application of the "lazytongs" device, which is well
known. The float of the elevator is shown at the left hand of the
engraving, and, as seen in the latter, there is an automatic weighing
machine, by which the material may be weighed as it is delivered, before
it goes to the bottom of the elevator, to be again transferred by its
means to the barge or granary. Simplicity, efficiency, and adaptability
to any position in which elevators of this class are desirable, are the
claims the patentees, Messrs. Behrns & Unruth, Lubeck, make for the
advantages of their apparatus.--_London Miller_.

[Illustration: IMPROVED FLOATING ELEVATOR.]

* * * * *

IMPROVED DREDGER.

We illustrate below a useful type of dredger made by Messrs. Rennie, of
Blackfriars, England. The drawing almost explains itself. The machine
consists of a double barge or pontoon, in which is erected a derrick.
This derrick works a "spoon" dredge at the end of a lever. The spoon, as
shown, is at its lowest position. It will make a forward stroke, through
about one-sixth of a revolution, and will thus become filled with
mud and be lifted above the surface of the water. The motion will be
imparted to it by the chain and pulleys seen at outer end of the derrick
jib. The jib will then be swung round over the bank on a hopper barge
and its contents delivered. The requisite power is supplied by the steam
engine at the end of the pontoon. Messrs. Rennie have made several of
these little dredgers, which are found very useful and handy in shallow
water.--_The Engineer_.

[Illustration: SINGLE BUCKET DIPPER DREDGER.]

* * * * *

RAILWAY ALARM WHISTLE.

In order to prevent a train passing a danger signal during a fog or
snowstorm without being seen by the engineer, the Southern Railway
Company of France have attached to the locomotive a steam whistle, which
is controlled by the signal. The whistle is connected with an insulated
metallic brush placed under the engine. Between the rails there is a
projecting contact bar, faced with copper, which is swept by the brush
when the train passes. This contact piece is connected with the
positive pole of a voltaic battery, the negative pole of which is in
communication with a commutator on the signal post, from which a wire
leads to the ground. When the signal is "line clear" the passage of the
brush over the fixed contact produces no result; but when the signal
marks "danger," the commutator brings the negative pole of the battery
in direct communication with the ground, and when the brush passes over
the contact the completion of the electric current causes the whistle to
be sounded, so as to alarm the driver.--_L'Ingen. Univ._

* * * * *

FURNACE FOR THE MANUFACTURE OF SULPHIDE OF CARBON.

Sulphide of carbon (CS_2) is prepared by passing the vapors of sulphur
over charcoal heated to redness. In laboratories, charcoal and roll
brimstone are employed so as to obtain as pure a product as possible;
but sulphide of carbon having now become so important a commercial
product, and being employed for so large a number of industrial
purposes, it has been found more economical to substitute coke for
charcoal and pyrites for brimstone.

The Messrs. Labois, in their system of furnace represented herewith,
have had in view the manufacture of this product under as economical
conditions as possible, by coupling over two connected fireplaces the
retort in which the pyrites is distilled, and that in which the reaction
of the sulphur and carbon takes place.

The pyrites is fed from the hopper, A, into a distributing box, B,
furnished with a valve which is maneuvered by a lever. From thence it
descends into the retort, G, where it is roasted by the heat of the
fireplace, L. The sulphur converted into a state of vapor passes through
the conduit, R, into the coke or charcoal retort, G', which is divided
into two parts by the partition, _g g'_, of refractory clay, and heated
by the fireplace, L'.

[Illustration: LABOIS'S SULPHIDE OF CARBON FURNACE.]

The conduit, R', leads the sulphide of carbon in a state of vapor to the
condensing apparatus. The uncombined sulphur which is carried along is
deposited in the first part of the retort by the arrangement of the
partition, which permits of passage only below. The registers, V and
V', permit of the introduction of the sulphur vapor and the exit of the
sulphide of carbon being regulated.

The apparatus is so easy of installation that it may be applied without
much expense to pyrites furnaces already in operation.

Wherever a manufactory of the product is to be started, the system
recommends itself by its simplicity, and by the facility with which the
operation may be watched and conducted.

* * * * *

BROUARDEL'S DRY INSCRIBING MANOMETER.

Brouardel's manometer, represented herewith, is designed for showing
graphically variations in the pressure of gas, either at the works
during the course of manufacture, or at any point whatever in the system
of piping.

For this purpose water manometers have hitherto been employed; but,
although the indications given by these are very accurate, their form
and weight are such as to render them not easily transportable; and
then, again, considerable care is necessary in putting them in place.

Mr. Brouardel's registering manometer does not give so accurate
indications, perhaps, but it possesses, as an offset, the merit of being
very portable and easily put in place; and, besides, it inscribes the
hour at which the pressure is exerted.

The apparatus consists of a metallic cylinder, A B, which carries a
circular shoulder, C, that rests on a plate, D--the latter being put in
motion by a clock which is wound up by means of a button under the base,
E, of the apparatus. The two standards, F F, carry a crosspiece which
supports a disk that closes freely the aperture of the drum, A B, in
such a manner as not to impede its rotation.

In the interior of the cylinder there is a metallic cup which is
connected with the central reservoir by an impermeable membrane, I.
These three parts form a closed chamber, into which the pressure comes
through a tube, F, provided with a cock. A spring, M, which counteracts
the pressure, is arranged between the crosspiece, G, and the bottom of
the reservoir. The latter carries also a small rod, K, which is provided
with a cord made of braided silk. This cord runs over a pulley, N, whose
axle carries at its other end a still larger pulley, O. Toward the
middle of the latter is fixed a silken cord which hangs down on each
side, after making several turns around the pulley. To the front cord
is attached a slide, Q, moving in a vertical direction, and to which is
fixed an inscribing style, R. The other extremity of the thread enters
the hollow upright, and carries a weight which is greater than the
combined weights of the slide, the membrane, and the internal reservoir.
The upright serves as a guide to this counterpoise.

In order to use the apparatus there is affixed to the cylinder, A B, a
sheet of paper divided in a vertical direction into as many parts as
the cylinder takes hours to make one revolution. The divisions running
horizontally represent centimeters of water or of mercury, according to
the strength of the spring, M, which should be so constructed as to be
in relation with the pressure. The operation of the apparatus may be
readily understood.

[Illustration: GAS INDICATOR OF MANOMETER.]

When the gas reaches the pressure chamber, the spring, M, contracts, and
consequently the counterpoise descends, and causes the cord, O, which
carries the slide and writing style, to wind around the pulley. When the
pressure diminishes, the movement takes place in an opposite direction.

The tracing is done by means of a special form of style giving indelible
curves through the medium of colored glycerine. The position of the
point is determined in such a way as to annul the friction of the pen,
and consequently to give it greater sensitiveness.

It should be remarked that the course of the rod, K, is amplified in the
tracing of the ordinates of the pressure according to the ratio of the
diameters of the pulleys, N and O.

The apparatus may be carried by hand by means of the handle, S, either
in or out of its case. To put it in operation, it is only necessary to
connect the apparatus with a gas burner (located near the place where
the variations of pressure are to be observed) by means of rubber
tubing. The apparatus may be employed under the same circumstances as
glass and U-shaped water manometers, with the further advantage that the
results are registered, and consequently can be more easily compared.

* * * * *

CENTRIFUGAL APPARATUS FOR CASTING METALS.

The apparatus represented in Figs. 1, 2, 3, and 4 is the invention of
Messrs. Taylor & Wailes, and is designed for casting metallic objects
in annular form, its arrangement being slightly varied according to the
nature of the objects to be cast. In all cases where a special form is
to be given to the outer or inner circumference of the object, or where
it is desired to exert a pressure on the circumference, such form or
pressure is obtained by the introduction of a core which may be expanded
or contracted as need may be. For this purpose an expansible, metallic
core is employed, the arrangement of which is shown in Figs. 1 and 2,
and which is so fashioned that the inner circumference of the ring to be
cast may receive the desired form. This core is formed of the pieces, g,
g', made of cast-iron or any other material which fuses with difficulty,
and which are placed in the revolving mould in such a way that after the
cooling of the pieces the parts, g, recede by the shrinkage of the piece
and thus free the core. The parts, g, of the core are in the shape of
circular segments, and are united at their external circumference by a
flange, along with which they form a shoulder piece for the casting.
As a consequence of the rapid revolution of the mould, these parts are
pressed by centrifugal force against the molten metal which is run into
the mould.

[Illustration: CENTRIFUGAL METAL MOULDING APPARATUS.]

The plan, Fig. 2, shows the arrangement of the parts, g, g', and allows
it to be seen that the pieces, g', act as wedges against the segments,
g, and push these out so as to form a perfect circle. The molten metal
cannot become oxidized in the mould, since it is shut off from contact
with the external air by the cap, C, which covers it. Oxidation may,
however, be further prevented by passing some deoxidizing or neutral gas
into the mould. For this purpose the mould is filled before the casting
is done with some such gas as illuminating gas, carbonic acid, nitrogen,
or hydrogen.

This improved process of casting may also be employed for objects which
do not possess an exactly annular section. The moulds are then arranged
eccentrically in a frame which is made to revolve rapidly during the
cooling of the metal In this way the pieces are less strongly compressed
at the places where they are nearest the center of rotation than a the
points where the radius is greater.

Figs. 3 and 4 show section and plan of an apparatus of this kind. The
sand moulds are arranged in the frame, a b which revolves about the
axle, c. In the moulds there are iron cores, h, which press the metal
during rotation and thereby produce compact pieces.

* * * * *

APPARATUS FOR THE MANUFACTURE OF WOOD PULP.

For manufacturing wood pulp Mr. Dresel employs an apparatus such as
represented in Figs. 1 and 2, consisting of an upright cylindrical
reservoir, A, supported on a frame by means of trunnions, z. This
reservoir, which is of boiler plate, is furnished with a cover, D, which
has in its center a piece of tubing, with stop-cock, C. A series of
tubes, R, whose diameter and length are proportioned to the volume of
the boiler, A, is filled with the liquid which is contained in the
boiler, so as always to be able to rapidly produce a pressure of nine
atmospheres or more by direct heating. The flanges of the tubing are
provided with a cut-off of angle iron identical with that of the tube,
D. By means of this arrangement the cocks and the flanges, E, permit of
communication between the serpentine tubing, R, and the boiler being
interrupted; while the heat developed by the fire-place, F, causes an
active circulation in both the tubing and boiler.

[Illustration: DRESEL'S WOOD PULP APPARATUS. Fig. 1]

[Illustration: DRESEL'S WOOD PULP APPARATUS. Fig. 2]

To put the apparatus in operation the cover, D, is first unscrewed, and
there is put into the boiler a certain quantity of wood, which has been
divided up by a cutting machine of special form. Then the boiler is
filled to the proper height with the liquid necessary to dissolve the
incrusting materials, the cocks, B, being closed. Afterwards there
is fixed immediately beneath the angle-iron ring of the cover, D, a
perforated iron plate upon which the contents of the boiler rest when
the latter is turned up. Then the cover is fastened down and the boiler
is put in communication with the heating apparatus. The cocks, E and B,
are opened, so that the liquid may begin its movement in the tube, a,
the boiler, A, and the tube, n. As soon as the proper temperature
is reached for converting the wood into fiber and decomposing the
incrusting matters, the heat is shut off in case the tubing, R, is not
connected with another like boiler, and, after closing the cocks, E and
B, and shut off communication between the tubing and the boiler, the
latter is turned over and the cock, C, gradually opened in order to
allow the steam to escape. When the temperature has descended to 100 deg.
in the boiler the cover, D, may be opened, after the liquid has been
allowed to flow out through the cock, C. Next, lixiviation is effected
by connecting the cock, C, with the steam pipe, P, and causing steam
under pressure to enter the boiler, A. The action of the steam on the
contents of the latter, which are now converted into cellulose, mixed
with a large quantity of dissolved matters and of liquid, effects a
complete washing and permits of the recovery of considerable quantities
of useful chemical products. Moreover, the steam purifies, decolorizes,
and completely separates the fibers, and renders them more easily
susceptible of being bleached. Finally, the perforated bottom, S (which
is formed of two parts), is removed and the boiler emptied.

In order to have the operations under control, and for the purpose of
safety, there is riveted into the boiler, A, a tube, T, containing a
thermometer: and there is fixed to the tube, a, a pressure-gauge, M, and
a safety-valve. The level of the liquid is ascertained by means of a
gauge-cock, H.

* * * * *

RECENT PROGRESS OF INDUSTRIAL SCIENCE.

The thirty-fourth annual summer meeting of the Institution of Mechanical
Engineers began on Aug. 2, at Newcastle-on-Tyne. The following is an
abstract from the address of the president, Mr. E. A. Cowper.

He began by stating that as members of the Institution of Mechanical
Engineers, on revisiting their brother members and friends here in
Newcastle, after an interval of twelve years, they came as it were to
one of their natural homes; certainly to the home of one of the greatest
engineers that England has ever produced, and the birthplace of the
locomotive, which has done more than any other improvement, of our age
to lessen the cost of materials to the men who have to use them, and
therefore to cheapen and extend production in the most wonderful manner.
He then went on to say that it seems but a few years ago since George
Stephenson, at a meeting in 1847, proposed the resolution that the
Institution of Mechanical Engineers be formed. He was strongly supported
by a large number of the mechanical engineers of the country, and the
speaker had the honor of seconding the resolution that he be first
president. The intention was that engineers from all parts of the
country should join to form a compact body capable of discussing
and judging of all mechanical subjects and appliances. In this the
institution had been eminently successful, and it numbered among its
members mechanical engineers in every large town in the country, and has
increased in strength and importance.

Pages:
1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10