Sun, Wind, and Wave.

How They May provide the power of the Future.

By ARTHUR T. DOLLING.

The Strand Magazine - June 1912

HE four elements are four mighty giants who are, as
yet, but imperfectly tamed and harnessed to do man's bidding. When one reflects
upon these stupendous forces of Nature, it seems ridiculous that, after all
these centuries, puny flesh and blood, whether of man or beast, should be put to
any muscular effort at all in the cause of commerce and industry. The combustion
of coal, laboriously drawn from the bowels of the earth by manual labour in
order to produce the dynamic force of steam, seems a clumsy expedient when
billions upon billions of units of power, inherent in the wind and the waves,
lie idle upon the surface of the earth, at our very doors. Why are these forces
not utilized for the service of industry?

The recent coal strike has set the wits of the world's inventors at work
harder than ever to solve this question. Sir William Ramsay declares there is no
necessity to mine coal at all. Use the caloric power it furnishes, but leave it
in the bosom of the earth, instead of dragging it piecemeal to the surface. In
that way earth, the first of the elements, would join hands with fire in
producing power, and a million coal-miners would be free for the purposes of
agriculture, which, although becoming more and more mechanical, will always
require human supervision.

By this plan thirty per cent. of the coal energy can be converted into useful
work, instead of a meagre fifteen per cent., which, by present methods of coal
consumption, is the best efficiency obtainable.

"There is absolutely nothing," says Sir William, "so far as I can see, to
prevent a bore-hole from being put down until the coal stratum is reached, and
concentric tubes being used to set the coal on fire (by electricity), and to
blow air down to enable the coal to burn as a preliminary operation. When
sufficient heat has been engendered, the amount of air sent down might be
restricted. Coal with plenty of air gives off carbon di-oxide
CO2. When half-burned it gives CO, or what is called
Dowson's gas, which is used for gas-engines. If steam were blown in it would
give a mixture of hydrogen and carbonic oxide, or water-gas, which also is
frequently used for gas-engines. Bring your gas-engines to the mouth of your
pit or bore-hole, and produce your power there."

The foregoing illustration (1)
will make the details of this striking scheme quite easy to understand.

This power is to be used to generate electricity, and in this form the coal
energy can be distributed over hundreds of miles with a further waste that is
almost negligible. Thus we may double the life of our coal-mines, and, in
addition, the smoke problem will have become a thing of the past.

But the power yielded by coal is finite -- science can already look ahead and
discern the limits of Britain's coal supply. Earth's oil supply is vaster, but
here the problems of production and transportation are very great. Inventors
from an early period have turned their attention to that wondrous reservoir of
heat from which we, in these islands, derive a diluted and strictly limited
quantity, but, even as it is, possibly capable of supplying all our wants.
Several inventors have devised ingenious solar engines which will boil an egg on
a winter's day. But from the cooking of an egg to the running of a factory is a
great gulf fixed. Will that gulf ever be bridged? Yes, if conditions
imperatively demand it. If necessary, lenses and instruments of leviathan size
could be constructed which would so focus the sun's rays as to produce a hundred
times more heat than any solar engine hitherto in use in this country.

Some years ago, in the garden of the Tuileries, in
Paris, there was witnessed a remarkable experiment with M. Pifri's latest
improvements in the solar generator (2).
There was set up on this occasion, in the garden near the large reservoir at
the foot of the Jeu de Paume stairs, an insolator that measured 3·5 metres in
diameter at the opening of the reflector. The steam obtained in the boiler
carried by the reflector at its focus was utilized by a small vertical motor of
thirty kilogrammetres power, which actuated a Marinoni printing press working
off an average of five hundred copies of a newspaper per hour.

Solar heat is the basis of the new Funke apparatus(3). It is used to create a
current of air by which a reciprocating engine or turbine is driven. The air is
heated by the sun in a broad channel, or flue, situated on the south side of a
hill and terminating in a tunnel and chimney. The motor is placed at the
entrance to the tunnel, and the channel may be roofed by an absorbent of heat
which will give out energy even after sunset. Several new solar engines have
lately been patented, and one - that invented by Mr. Shepherd - is now working
in Philadelphia.

A solar stove seems like going back to barbarism and
sun-baked viands, but to grill a chop or stew a partridge by the heat of the sun
is quite a different matter. The Adams apparatus now in use in India and Egypt
consists of a conical reflector made of wood and lined with common silvered
sheet glass (4). Inside
there is placed a coffin-cylinder-wise vessel enclosed by a glass cover. The
cooking vessel is raised about four inches from the bottom, and the glass cover
is five inches longer than the vessel and two inches wider, which leaves an
interval of four inches of hot air under the boiler, and one inch all round and
at the top.

The wedge under the apparatus is to keep it inclined, so that the rays of the
sun may fall perpendicularly on the boiler, glass being diathermanous to the
direct or reflected rays of the sun and non-diathermanous to obscure heat. The
rays penetrate the glass and, striking on the vessel, become transformed into
obscure heat, when they are retained by the glass. The glass cover over the
boiler is made octagonal because, in that form, common window-glass can be
used. Of course, a glass dome such as is used for covering clocks and statuettes
would be better, and equally of course a copper reflector electro-plated with
silver would be better than any reflector. Both of these articles are made
octagonal in order that cheap material may be employed. The position of the
apparatus requires to be changed about every half-hour, to face the sun in its
apparent course from east to west.

The rations of seven soldiers, consisting of meat and vegetables, were
thoroughly cooked by it in two hours in January, the coldest month of the year
in Bombay, and the men declared the food to be cooked much better than in the
ordinary manner. Several people in Deccan have tried it, and always with
success. If the steam be retained the dish is a stew or a boil; if it be allowed
to escape the food is baked. It now only remains for Lord Haldane to adapt this
contrivance for summer home use amongst the Territorials.

Mr. Frank Shuman, of Philadelphia, has recently completed and tested one of
his sun-engines, which is to be used in Egypt for pumping up water. It can lift
three thousand gallons of water every minute to a height of thirty-three feet,
when working in favourable weather at Philadelphia. In the hotter climate of
Egypt it will naturally do much more work in the same time.

The most important feature of a sun-engine is the steam-generator. In the
engine which Mr. Shuman has built for Egypt the water-"boxes " which catch the
rays of the sun to generate steam have each a space of six feet between the tops
of their two mirrors, and they are massed together over a space of five thousand
square feet. When the mirrors are included the total heat-catching area is about
ten thousand three hundred square feet.

Mr. Brossell's invention is one of at least a hundred
of the same class -- an apparatus for compressing and exhausting air by the
action of the waves (5). It
consists of a tank open at the bottom, which is placed so that the closed top
is above high-water mark and the bottom below low-water mark. The action of the
waves compresses air in the upper part of the tank and forces it through the
valve into a pipe leading to a motor. The air is drawn into the tank again
through pipe and valve. Should the valve cease to act, a valve prevents undue
compression in the exhaust-pipe, and if more air is required in the tank, a
chamber fitted with a valve, arranged on the high-pressure side of the motor,
allows the ingress of air.

A simple form of tidal engine was patented by Mr. Laird only last year. A
huge walled basin is formed on the seashore into which the tide flows over a
long mill-wheel, the power being conducted by belts to a dynamo. When the tide
ebbs - basin being full - the motion of the wheel is reversed. It is calculated
that, according to this method, enough electricity would be produced to run all
the trains on a railway having its terminus on the coast, or to work in
conjunction with another tidal wheel at the other end of the line.

The Merlini wave-mill is a float arranged on a very similar principle above a
pumping device, and actuated by the rise and fall of the waves. The piston-rod
of the pump is rigidly and directly secured to the bottom of the float, which is
guided by framework.

Another apparatus, patented by Messrs. Reynolds,
utilizes the forward and receding motion of the waves (6).
As will be seen from the illustration, the large suspended shutters are set in
motion by the action of the tide, and are attached to air-pumps which supply
compressed air for use in driving engines on the land.

Most tidal engines are, however, based on the principal of a floating mass,
slowly rising and falling with irresistible force and actuating complicated
machinery multiplying the velocity of the central axis. The force of the tide is
terrific, and there is no doubt that some way of harnessing it for the benefit
of man will shortly be found.

As to wind-engines, their name is legion, most of them being, of course,
variations and amplifications of the familiar windmill, not, however, so
familiar in England as it deserves to be. With a surface sufficiently exposed
great power is obtainable for operating a dynamo. One cannot help marvelling at
the general neglect of this source of industrial energy. They are used for
draining purposes in Holland and Norfolk and for mining in several countries. It
was Lord Kelvin who first proposed to utilize them in charging electric
accumulators. A single windmill at Faversham, of fifteen horse-power, raised, in
ten months, twenty-one million gallons of water from a depth of one hundred and
nine feet; but American windmills have far exceeded this record of usefulness.
These latter have the sails arranged in an annulus or disc, the sails consisting
of narrow slats arranged radially, each board inclined at a constant angle of
weather. In what are called centrifugal governor mills the slats are set in a
bar; by rotating the bar the slats are brought end on to the wind, the action
resembling the shutting of an umbrella. The slats are held up to the wind by a
weight, and are also connected to a centrifugal governor. If the speed of the
governor increases the balls fly out and lift the weight, and at the same time
the sails are partially furled. There are five hundred windmill patents in
America alone. If a single horse-power wind-engine were affixed to the roof of
every London house, think of the enormous saving to the hands, the legs, and
the backs of half a million housewives and domestic servants. Every family could
then keep its horse or at least its horse-power; every householder could afford
a motor; and, from an artistic standpoint, what a great gain to the eye it would
be to see London a city of windmills.

Our last example (7)
is yet another instance of an invention, due to a writer of fiction, which may
very well in time take its place in practice. It appears, indeed, to be quite as
likely as many of the inventions which have actually been tried and found
feasible. The writer and inventor is a Frenchman, Octave Beliard,and a
translation of his story appeared in our last Christmas Number, but without an
illustration such as that which we now give, and which makes its ingenuity very
much easier to understand. The following is the description:-

"We were just then rounding a spur of the mountain, and suddenly there
appeared before me the most colossal object I have ever beheld. On that side the
waves broke on the very flank of the mountain. On the shore, two Cyclopean
pillars supported a steel axle twenty feet in diameter, on which turned a
gigantic angular lever. This lever, the construction of which recalled to some
extent the framework of the Eiffel Tower, was made up of great steel beams,
united by an intricate network of cross-beams and ties. Its smaller arm,
relatively rather short, was bolted at its extremity to a great raft floating in
the sea - a raft that was ten times larger than the largest steamer afloat, and
heavily laden. The long arm of the lever, more than six hundred feet in length,
supported at its extremity an immense tank, of a sufficient capacity to hold
some three hundred tons of water.

"`You see,' said our guide, `the incoming tide, while it causes the raft to
rise, raises at the same time the smaller arm of the lever and, consequently,
lowers the extremity of the longer arm to sea-level The tank at once, of course,
fills with water. As the tide ebbs again the raft descends, dragging down the
smaller arm after it, while the long arm, little by little, rises, until the
extremity is at the height of the crater, where the tank tilts and empties its
contents. Six hours are occupied in the ascent, six in the descent. As you are
aware, there are two tides in the twenty-four hours, so that every day six
hundred tons of water, more or less, are raised to the boiler. To set up the
machine necessitated an enormous amount of labour, but ever since its erection
it has gone on working by itself, and will continue to do so indefinitely,
without any attention whatever."'