Scientific American Suppl. No. 299

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

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The last twelve years have been marked by many very important
changes, while low prices have generally ruled. Among other causes of
fluctuations in demand and supply (and consequently in values) must be
mentioned the occurrence and the threatening of foreign wars, which
disturbed the course of commerce greatly for some years. Such causes
must be considered as extraneous to the sphere of influence possessed by
good or bad manufacturing or engineering. Mr. Cowper does not look upon
the very great expense of improved war material and implements as an
unmixed evil for this country; for it so happens that we can better meet
such outlay than any other nation, and thus our wealth gives rise to
greater power and security than our neighbors possess; while, seeing
that we are not an aggressive nation, such power tends materially at
once to the progress of this country, and to the peace of the world.
Having referred briefly to one cause of disturbance to the progress of
mechanical engineering, he named another, which at the present moment is
occupying thoughtful men to a considerable extent, namely, the arbitrary
imposition of duties and bounties for the professed object of protecting
manufactures, while in fact they constitute taxes on a nation for the
benefit of a few individuals. In some countries excessive duties have
been imposed, as against our manufactures, and it is even proposed to
increase them; while in other cases bounties are actually paid out of
the public purse to men engaged in a particular manufacture, on their
exporting to this county certain of their wares, as, for instance,
beet-root sugar.

One extremely significant lesson, resulting from high duties--which it
may be hoped will not be thrown away upon the American public--is, that
whereas our cousins on the other side of the water used to build almost
all the American "liners" of wood, they now find that, with their
excessive duties against the importation of iron and steel from England,
they cannot compete with English iron and steel ship-builders and marine
engineers. This is one of those damaging effects naturally produced
by excessive protective duties; which, while they enable American
ironmasters quickly to realize enormous fortunes, drive the American
merchants to purchase English ships, or intrust their merchandise in
English bottoms, as it is impossible to maintain protective duties at
sea.

Whatever fluctuations have occurred, it is now pretty clear that
several foreign nations have settled down to cultivate and extend their
manufactures, and we are brought face to face with the fact--which has
now been for some years growing to its present importance--that many
articles which in years gone by we thought it to be our especial
province to supply, are now produced in the very countries requiring
them. Even Spain is awakening to the advantage of producing hematite
iron from her own excellent ores, with English and Welsh coke carried
out in the same ships that bring Spanish ores to this country.

Now with regard to the possibility of any foreign nation eclipsing us in
our manufactures, he would say at once that any such successful rivalry
on their part is far worse than the effect of any duties, even if they
be prohibitive; for it means rivalry in the markets of the world, and
possibly in our own markets here at home. Therefore it behooves us
to put our house in order, and see in what way we may be enabled to
manufacture better and with greater economy. Mechanical engineering is
of such extreme importance in advancing civilization, that it is most
essential that its progress should be rapid and unimpeded.

Perhaps the very large increase in steam shipping, and the change from
sailing ships and paddle steamers to screw steamers, has been one of the
greatest improvements of recent times, and it is none the less real
or important from having been gradual, while the result to this
neighborhood has been most beneficial. This change has been due in great
measure to the introduction of very economical marine engines, chiefly
of the compound type, together with better boilers carrying a higher
pressure.

The speed and regularity of ocean steamers has also greatly improved,
and one small scientific improvement has added much to the safety of
traversing such seas as the Atlantic at a high speed--namely, the
careful and continual use of a good thermometer, to ascertain constantly
the temperature of the sea-water at the surface. For if an iceberg is
floating within a quarter of a mile--or even half a mile, if the sea is
pretty smooth--the surface water will be several degrees colder than the
rest of the sea; since the very cold fresh water, resulting from the
melting iceberg, floats on the top of the sea water for some distance.

No doubt the use of iron, and now of steel, has contributed most largely
to the increase of shipbuilding in this country. Good arrangements
of water ballast have also proved very useful; and steam cranes and
arrangements for loading and discharging cargo have greatly promoted the
use of steam colliers, enabling them to make more voyages in the year.

Closely connected with marine engineering is the great improvement in
the economy of stationary engines, which has become more fully developed
during recent years, both in reference to waterworks engines and factory
engines. In aid of stationary engines, "surface evaporator condensers"
have been found very useful, particularly where the supply of water is
very limited; and at waterworks it is now very common to pass the whole
water pumped through a surface condenser, thus giving a good vacuum
without the expenditure of any water, and with the result of only
raising the temperature of the water a very few degrees, on account of
its large volume.

Locomotives have shared to some extent in the general improvement in
machinery. The boilers are better made, and are safer at the higher
pressures now carried than they were formerly with a low pressure.
Several new valve gears of great promise have been brought forward, both
for locomotives and marine engines. Among them Joy's motion should be
again noticed. Mr. Webb says: "The engine shown at Barrow has been at
continuous work ever since the Barrow meeting, and has run 30,278 miles;
we had it in for examination on the 18th inst., and found the motion
practically as good as the day it went out of the shop, more especially
the slides, about which so many of the people who spoke at the meeting
seemed to have doubts. I do not think you could get a visiting card
between the slides and the blocks; in fact, the engine has been sent out
to work again, having had nothing whatever done to it. The first thing,
of course, that will require doing will be the tires; as far as I can
see nothing else will want doing for some time."

A very fine engineering work has now been accomplished in America in
reference to navigation, namely, the deepening of the channel at the
mouth of the Mississippi through the training of the river by jetties
and banks. In consequence, ships of large size may now go up the
river--there being plenty of deep water above the mouth--and bring down
grain cargoes, without the expense and inconvenience of transshipment,
thus reducing the freight of corn to this country. This great
improvement is the work of Captain Eads. A somewhat similar improvement
was the blowing up of about 50,000 tons of rock from the bed of the
river at the narrow pass of Hell Gate, near New York. It is to be hoped
that these good examples may spur on our friends on the Continent to
improve their harbors, so that large channel boats may cross with
comfort to the passengers, thus avoiding the excessive expense that a
tunnel would involve.

Great improvements have been made in the illumination of lighthouses
by oil lamps; a light equal to 1,300 candles has been produced by Mr.
Douglass, of the Trinity House, and now two such lights will be placed
one above the other, where required. The electric light has made such
numerous and rapid strides that it is impossible even to notice its
various applications; but on the one hand the lighting by Dr. Siemens
of four miles of dock frontage at the Albert Dock of the London and St.
Katherine Dock Company, together with the railway behind the warehouses,
and the warehouses and ships themselves, and, on the other hand, the
elegant and steady domestic light of Mr. Swan, are excellent examples
of the two extremes in this department. I believe we shall have the
pleasure of closely observing the Swan light during our visit here. The
lighthouse electric light is also a noble application of the great power
of a single electric light on the arc principle. The most powerful
electric light in the world is situated near here on the coast, between
the Tyne and the Wear. It is possible, and even probable, that one of
the great uses to which electric force will be applied eventually, will
be simple conveyance of power by means of large wires; and as a higher
percentage of power is gradually being realized, this method will become
more economical. I may mention that 60 per cent. has already been
obtained.

The invention of Messrs. Thomas & Gilchrist, by which a very large field
of ironstone is now, for the first time, made available for the purpose
of making good steel by the Bessemer process, bids fair to make very
considerable alterations in the steel-making trade, and in the hands
of Mr. E. Windsor Richards it has been made a great success, while in
Germany there are several works also using the process largely. Mild
steel is now being used to a great extent for the construction of steam
boilers as well as of ships, and in steel castings for a variety of
purposes, such as spur wheels, frames of portable engines, manhole door
frames, etc., etc. Among the uses to which steel may be put is the
manufacture of steel sleepers in place of wood. It is a very encouraging
fact that there are now, or rather there were already, at Dusseldorf, in
1880, 70,000 tons of iron or steel railway sleepers in use in Germany.
Mr. Webb, of Crewe, has exhibited a very promising arrangement of
sleepers and fastenings, to be made either of iron or steel. Steel
sleepers should also be used for tramways.

If, now, some clever ironmaster could only accomplish the task of making
a good "street pavement" of cast iron, the increased demand for pig
metal would be enormous. It has nearly been accomplished already, by
several different modes of construction; and there are very many streets
where the luxury of wood pavement, which wears very rapidly, cannot be
afforded, and where macadamizing will not stand the wear and tear of the
heavy traffic. The use of ingot steel, or very mild steel, for making
tin-plates is now an established thing, and manufacturers are now taking
this metal for making large tinned sheets up to seven by three feet.

The making of casks by machinery, cheaper and better than those made by
hand, is now an accomplished fact by Mr. Ransome's machines. There are
twelve factories already established abroad, some turning out 2,000 or
3,000 casks a week. This is a good case of English invention taking the
lead in a manufacture.

Among good mechanical appliances that have been proved to be highly
valuable to the civil engineer may be mentioned the excavating machine,
which answers well for certain soils and situations, though not for all;
and the dredger of Messrs. Bruce & Batho, for excavating from the inside
of piers in water.

In manufacturing chemistry, which, with its numerous mechanical
appliances, is much indebted to mechanical science and engineering,
great advances have been made during the last dozen or twenty years.
Aluminum has been brought into practical use to a large extent, it
being at once a very light metal and a very cleanly one. "Anthracine,"
obtained from coal tar, has been manufactured largely for the purpose of
producing the various brilliant dyes now so common.

New materials for making candles have been manufactured, in some cases
by purely mechanical means, such as boiling together for some hours, at
a pressure of several hundred pounds per square inch, neutral grease and
water, when the water takes up the base, viz., glycerine, and leaves
the grease as an acid grease. This same effect has been noticed in some
steam boilers, where the same water, without admixture of fresh, has
been used over and over again with surface condensers. Then, again,
large rotating chemical furnaces have been introduced; and improved
glass furnaces--particularly tank glass furnaces, in which the batch is
put in at one end, and the working holes are toward the other end--have
cheapened the actual production of glass, and are being worked largely
on the Continent, and to some extent in this neighborhood. Toughened
glass has made some progress for certain purposes. Besides the improved
and extended use of glass in lighthouse illumination, it has again
been pressed into our service for other purposes, through our greatly
extended knowledge of the laws of optics.

Spectrum analysis has become of practical use, and photographs of the
various Fraunhofer lines in the spectrum have been taken as permanent
records of each experiment. That such extended knowledge should have
been developed by that one little instrument, the lens, is but natural;
for the lens is at once the means by which we discover the extreme
magnitude of some portion of the infinite works of the Almighty in the
architecture of the heavens, and by which we appreciate to some extent
the extremely minute markings of a diatom that one cannot see with the
naked eye. At the same time we feel sure that there are other markings
still smaller, as every increase in the power of the microscope has
always rendered visible some markings still smaller than the last;
and in like manner has every increase in the power of the telescope
developed more worlds and suns far away from our system and beyond our
Milky Way. An approach to the infinite in minuteness and to the infinite
in magnitude and distance is thus furnished to us by one instrument
alone.

There was but one further observation that he would venture to make, and
it is this.

When one looks back upon the goodly list of clever men and benefactors
of the human race, who have lived, say, during the last hundred years,
one is sometimes tempted to wish that more of those scientific men, who
have had the most brilliant ideas, and been our greatest discoverers,
should have striven to carry out their discoveries into practice. For
instance, take Faraday's beautiful discoveries in electricity. It was,
in a manner, left to Sir Francis Ronalds, Professor Daniell, Professor
Wheatstone, Fothergill Cooke, Dr. Siemens, and others, to develop from
those discoveries the "intelligence wires," and "bands," that now
encircle the earth, and unite nations, and do so much to prevent
misunderstandings.

It is gratifying to know that the engineering profession has not been
forgotten when honors have been conferred on distinguished men; and
among others may be named Sir William Fairbairn, Sir John Rennie, Sir
Peter Fairbairn, Sir Charles Fox, Sir William Armstrong, Sir Joseph
Whitworth, Sir John Hawkshaw, Sir John Coode, Sir William Thomson, Sir
Joseph Bazalgette, Sir Charles Hartley, Sir Charles Bright, Sir James
Ramsden, Sir John Anderson, Sir George Elliot, Sir Daniel Gooch, Sir
Henry Tyler, Sir Samuel Canning, Sir Edward Reed, and Sir Frederick
Bramwell. With many noble examples before us, and with signs of an
improvement in many branches of commerce, he trusted that the latter
part of the present century will, with somewhat greater exertion of
thought and enterprise on our parts, be marked, not only by numerous
small improvements, but by many substantial inventions for the good of
mankind.

* * * * *

THE HOBOKEN DRAINAGE PROBLEM.

Our thriving neighbor, Hoboken, just across the Hudson River, has a
large and vitally important problem to solve. Of the 720 acres within
the city limits, 270 acres lie at a considerable height above the river
and constitute what are known as the knoll or uplands of Hoboken.
Between this low ridge and Palisade Ridge lie 450 acres of marsh lands
or meadows, 140 acres of which have already been built upon. The marsh
is about half a mile wide, and something like a mile and a half long,
extending southward into Jersey City. The surface is a network of matted
vegetation and roots perhaps five feet deep, and under that lies a mass
of blue clay or river silt 100 feet or more in depth. The original
tidal flow over these marsh lands has been obstructed by viaducts for
railroads and streets, leaving only two natural outlets, a sluice way at
Fifteenth street on the north, and on the south a basin constructed by
the D. L. & W. R. R., 100 feet wide, and 2,300 feet long. The average
level of the marsh land is three feet above mean low water and a foot
and a half below mean high water. In the part built upon the streets are
but two feet above mean high water.

During long easterly and northerly storms, especially at times of high
spring tides, the level of the water in the Hudson is often such as to
cover the meadows even at low tide; and on several occasions the water
at high tide has been 41/2 feet above the level of the meadows, and a foot
or more above the established grade of the streets.

The problem is to drain these marsh lands so as to make them properly
habitable and to protect them from invasion by high tides and storm
waters.

The first drainage map of the district was made about fifteen years ago;
since then over $100,000 have been expended on tidal sewers and other
devices, and several acts have been passed by the New Jersey Legislature
in furtherance of the work. An extended review of the plans proposed
and the experiments made thus far is given in a report presented to the
Board of Health and Vital Statistics, last May, by Engineers Spielmann
and Brush. Ten years ago Mr. Arthur Spielmann, on being directed by the
City Council to prepare plans and estimates for a contemplated sewer in
Ferry street to the western boundary of the city, reported adversely
to the project, believing that such a sewer would fail to answer the
purpose of its construction.

There were but two ways, he thought, of securing the end desired: First,
by raising the grade sufficient to give a good drainage; second, by
making reservoirs and forcing the drainage matter out into the river by
steam pumps. The first method he found impracticable on account of the
cost of filling in so large an area and of raising the large number of
houses already on the low ground. The second plan was recommended as
being much cheaper and entirely practicable. Substantially the same
position is taken in the report of last May, wherein it is alleged that
the superior economy of a pumping system has been sufficiently attested
by several eminent hydraulic engineers who have since investigated the
problems involved. On a small scale the efficacy of the pumping system
has been practically tested, first, in Meadow street, between Ferry and
First streets, and more recently in the southern part of the city, where
a number of property owners have kept twenty-five acres free from water
(except during storms) by means of a private pump.

The comparative economy of the pumping system is shown by estimates
in detail of the cost of constructing and operating such a system in
contrast with, the cost of raising the grade and introducing tidal
sewers. Under both systems the cost of the ordinary sewers will be
about the same. A proper system of tidal sewers, it is claimed, will
necessitate the raising of the grade of the streets on the low lands
to a height at least ten feet above mean high water. The extra cost of
raising the streets is estimated at $3,000,000. The cost of the pumping
system, with machinery and power sufficient to remove all storm water
and sewage, is put at $150,000, while the running expenses, including
interest on the first outlay, are put at $30,000 a year. The interest on
the preliminary expenditure of the first plan considered is $180,000 a
year, or six times as much as the pumping system would involve.

According to the estimates made by Engineer Kirkwood, in his report
of 1874, a total pumping capacity of 134,500,000 gallons a day will
ultimately have to be provided to meet the requirements during the
heaviest storms, besides some six or seven million gallons a day of
sewage proper, exclusive of storm waters. Not more than half that amount
of pumping will be required at first, the increase to be made gradually
as the marsh land is built upon.

* * * * *

ARTISTS' HOMES--No. 14--"BENT'S BROOK."

Our plate illustrates the residence of Mr. J. E. Boehm, A.R.A., the
sculptor. Bent's Brook is situated at Holmwood, not far south of
Dorking, on the Mid-Sussex line, and commands some fine views of
well-timbered country. The site itself is comparatively low, and the
soil being clay it was advisable to keep the building well out of the
ground, and in this way a rather unusually high elevation for such
a house was obtained. The plan is very compactly arranged, with an
ingenious approach to the well-centered hall and staircase, over
which, by a mezzanine contrivance, a good store place is secured. The
drawing-room has a belvedere bay, reached from the garden by an external
stair, under which is a covered garden seat. A balcony overlooking the
garden leads also from the drawing-room, and a billiard room is arranged
on the basement level with a separate entrance from the porch. A
tradesmen's entrance is provided elsewhere. The kitchen and offices are
on the lower floor level, and a kitchen yard is conveniently placed at
the rear. Red brick, with cut-brick dressings, is the material used
throughout for the walls, the upper parts of which are hung with
ornamental tiles. The gables are enriched with wide, massive barge
boards, and the roof is surmounted with a white wooden cupola over the
principal staircase. The terracotta panels along the entrance front,
over the principal floor windows, were designed by Mr. Boehm himself.
The work was executed by Mr. H. Batchelor, builder, of Betchworth, and
the architect of the house was Mr. R. W. Edis, F.S.A., who superintended
its erection.--_Building News_.

[Illustration: ARTISTS' HOMES No. 14 "BENT'S BROOK."]

* * * * *

ON SOME RECENT IMPROVEMENTS IN LEAD PROCESSES.

[Footnote: Lately read before the Institute of Mechanical Engineers.]

By NORMAN C. COOKSON, of Newcastle.

The author began by stating that probably in few trades have a smaller
number of changes been made during recent years, in the processes
employed, than in that of lead smelting and manufacturing. He then
briefly noted what these changes are, and went on to describe the "steam
desilverizing process," as used in the works of the writer's firm, and
in other works licensed by them, which process is the invention of
Messrs. Luce Fils et Rozan, of Marseilles. It is one which should
commend itself especially to engineers, as in it mechanical means
are employed, instead of the large amount of hand-labor used in the
Pattinson process. It consists in using two pots only, of which the
lower is placed at such a height that the bottom of it is about 12
in. to 15 in. above the floor level, while the upper is placed at a
sufficiently high level to enable the lead to be run out of it into
the lower pot. The capacity of the lower pot, in those most recently
erected, is thirty-six tons--double that of the upper one. Round each
pot is placed a platform, on which the workmen--of which there are two
only to each apparatus--stand when skimming, slicing, and charging the
pots. The upper pot is open at the top, but the lower one has a cover,
with hinged doors; and from the top of the cover a funnel is carried
to a set of condensers. At a convenient distance from the two pots is
placed a steam or hydraulic crane, so arranged that it can plumb each
pot, and also the large moulds which are placed at either side of the
lower pot. The mode of working is as follows:

The silver lead is charged into the upper pot by means of the crane.
When melted, the dross is removed, and the lead run into the lower, or
working pot, among the crystals remaining from a previous operation.

When the whole charge is thoroughly melted, it is again drossed; and in
order to keep the lead in a thoroughly uniform condition, and prevent it
setting solid on the top and the outside, a jet of steam is introduced.

To enable this steam to rise regularly in the working pot, a disk-plate
is placed above the nozzle, which acts as a baffle-plate; and uniform
distribution of the steam is the result. To quicken the formation of
crystals, and thus hasten the operation, small jets of water are allowed
to play on the surface of the lead.

This, it might be thought, would make the lead set hard on the surface;
but the violent action of the steam acts in the most effectual manner
in causing the regular formation of crystals. Owing to the ebullition
caused by this action of the steam, small quantities of lead are forced
up, and set on the upper edges and cover of the pot. From time to time
the valve controlling the thin stream of water playing on the top of the
charge is closed, and the workman, opening the doors of the cover in
rotation, breaks off this solidified lead, which falls among the rest of
the charge, and instantly becomes uniformly mixed with it.

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