An example of a modern traction engine may be found attached to one or more heavy cars adapted for street work, and on which may be found apparatus for making the mixed materials of which the roadbed is to be constructed, and all of which is moved along as the road or street surface is completed. When these fine roads become the possession of a country light traction engines for passenger traffic will be found largely supplanting the horse and the steam railroad engines.
Brakes, railway and electric, have already been referred to in the proper chapters. In the latest system of railroading greater attention has been paid to the lives and limbs of those employed as workmen on the trains, especially to those of brakemen. And if corporations have been slow to adopt such merciful devices, legislatures have stepped in to help the matter. One great source of accidents in this respect has been due to the necessity of the brakemen entering between the cars while they are in motion to couple them by hand. This is now being abolished by automatic couplers, by which, when the locking means have been withdrawn from connection or thrown up, they will be so held until the cars meet again, when the locking parts on the respective cars will be automatically thrown and locked, as easily and on the same principle as the hand of one man may clasp the hand of another.
The comfort of passengers and the safety of freight have also been greatly increased by the invention of Buffers on railroad cars and trains to prevent sudden and violent concussion. Fluid pressure car buffers, in which a constant supply of fluid under pressure is provided by a pump or train pipe connected to the engine is one of a great variety.
Another notable improvement in this line is the splendid vestibule trains, in which the cars are connected to one another by enclosed passages and which at their meeting ends are provided with yieldingly supported door-like frames engaging one another by frictional contact, usually, whereby the shock and rocking of cars are prevented in starting and stopping, and their oscillation reduced to a minimum.
As collisions and accidents cannot always be prevented, car frames are now built in which the frames are trussed, and made of rolled steel plates, angles, and channels, whereby a car body of great resistance to telescoping or crushing is obtained.
CHAPTER XXIX.
SHIPS AND SHIP-BUILDING.
“Far as the breeze can bear, the billows foam,
Survey our empire, and behold our home.”
“Ships are but boards,” soliloquised the crafty Shylock, and were this still true, yet this present period has seen wonderful changes in construction.
The high castellated bows and sterns and long prows of The Great Harry, of the seventeenth century, and its successors in the eighteenth, with some moderation of cumbersome matter, gave way to lighter, speedier forms, first appearing in the quick-gliding Yankee clippers, during the first decade of the nineteenth century.
Eminent naval architects have regarded the proportions of Noah’s ark, 300 cubits long, 50 cubits broad and 30 cubits high, in which the length was six times the breadth, and the depth three-fifths of the breadth, as the best combination of the elements of strength, capacity and stability.
Even that most modern mercantile vessel known as the “whale-back” with its nearly flat bottom, vertical sides, arched top or deck, skegged or spoon-shaped at bow and stern, straight deck lines, the upper deck cabins and steering gear raised on hollow turrets, with machinery and cargo in the main hull, has not departed much from the safe rule of proportions of its ancient prototype.
But in other respects the ideas of Noah and of the Phœnicians, the best of ancient ship-builders, as well as the Northmen, the Dutch, the French, and the English, the best ship-builders of later centuries, were decidedly improved upon by the Americans, who, as above intimated, were revolutionizing the art and building the finest vessels in the early part of the century, and these rivalled in speed the steam vessels for some years after steamships were ploughing the rivers and the ocean.
Discarding the lofty decks fore and aft and ponderous topsides, the principal characteristics of the American “clippers” were their fine sharp lines, built long and low, broad of beam before the centre, sharp above the water, and deep aft. A typical vessel of this sort was the clipper ship Great Republic, built by Donald McKay of Boston during the first half of the century. She was 325 feet long, 53 feet wide, 37 feet deep, with a capacity of about 4000 tons. She had four masts, each provided with a lightning rod. A single suit of her sails consisted of 15,563 yards of canvas. Her keel rose for 60 feet forward, gradually curved into the arc of a circle as it blended with the stern. Vessels of her type ran seventeen and eighteen miles an hour at a time when steam vessels were making only twelve or fourteen miles an hour, the latter speed being one which it was predicted by naval engineers could not with safety be exceeded with ocean steamships.
These vessels directed the attention of ship-builders to two prominent features, the shape of the bow and the length of the vessel. For the old convex form of bow and stern, the principal of an elongated wedge was substituted, the wedge slightly hollowed on its face, by which the waters were more easily parted and thrown aside.
A departure was early made in the matter of strengthening the “ribs of oak” to better meet the strains from the rough seas. In 1810 Sir Robert Seppings, surveyor of the English navy, devised and introduced the system of diagonal bracing. This was an arrangement of timbers crossing the ribs on the inside of the ship at angles of about 45°, and braced by diagonals and struts.
Of course the great and leading event of the nineteenth century in the matter of inventions relating to ships was the introduction of steam as the motive power. Of this we have treated in the chapter on steam engineering. The giant, steam, demanded and received the obeisance of every art before devoting his inexhaustible strength to their service. Systems of wood-working and metal manufacture must be revolutionised to give him room to work, and to withstand the strokes of his mighty arm. Lord Dundas at the beginning of the century had an iron boat built for the Forth and Clyde Canal, which was propelled by steam.
But the departure from the adage that “ships are but boards” did not take place, however, until about 1829-30, when the substitution of iron for wood in the construction of vessels had passed beyond the experimental stage. In those years the firm of John Laird of Birkenhead began the building of practical iron vessels, and he was followed soon by Sir William Fairbairn at Manchester, and Randolph, Elder & Co., and the Fairfield Works on the Clyde.
The advantage of iron over wood in strength, and in power to withstand tremendous shocks, was early illustrated in the Great Britain built about 1844, the first large, successful, seagoing vessel constructed. Not long thereafter this same vessel lay helpless upon the coast of Ireland, driven there by a great storm, and beaten by the tremendous waves of the Atlantic with a force that would have in a few hours or days broken up and pulverised a “ship of boards,” and yet the Great Britain lay there several weeks, was finally brought off, and again restored to successful service.
Wood and iron both have their peculiar advantages and disadvantages. Wood is not only lighter, but easily procured and worked, and cheaper, in many small and private ship-yards where an iron frame and parts would be difficult and expensive to produce. It is thought that as to the fouling of ships’ bottoms a wooden hull covered with copper fouls less, and consequently impedes the speed less; that the damage done by shocks or the penetration of shot is not so great or difficult to repair, and that the danger of variation of the compass by reason of local attraction of the metal is less.
But the advantages of iron and steel far outnumber those of wood. Its strength, its adaptability for all sizes and forms and lines, its increased cheapness, its resistance to shot penetration, its durability, and now its easy procurement, constitute qualities which have established iron ship-building as a great new and modern art. In this modern revolution in iron-clad ships, their adaptation to naval warfare was due to the genius of John Ericsson, and dates practically from the celebrated battle between the iron-clads the Merrimac and the Monitor in Hampton Roads on the Virginia coast in the Civil war in America in April, 1862.
Although the tendency at first in building iron and steel vessels, especially for the navy, was towards an entire metal structure, later experience resulted in a more composite style, using wood in some parts, where found best adapted by its capacity of lightness, non-absorption of heat and less electrical conductivity, etc., and at the same time protecting such interior portions by an iron shell or frame-work.
One great improvement in ship-building, whether in wood or metal, thought of and practised to some extent in former times, but after all a child of this century, is the building of the hull and hold in compartments, water-tight, and sometimes fire-proof, so that in case of a leakage or a fire in one or more compartments, the fire or water may be confined there and the extension of the danger to the entire ship prevented.
In the matter of Marine Propulsion, when the steam engine was made a practical and useful servant by Watt, and men began to think of driving boats and ships with it, the problem was how to adapt it to use with propelling means already known. Paddle-wheels and other wheels to move boats in place of oars had been suggested, and to some extent used from time to time, since the days of the Romans; and they were among the first devices used in steam vessels. Their whirl may still be heard on many waters. Learned men saw no reason why the screw of Archimedes should not be used for the same purpose, and the idea was occasionally advocated by French and English philosophers from at least 1680, by Franklin and Watt less than a century later, and finally, in 1794, Lyttleton of England obtained a patent for his “aquatic propeller,” consisting of threads formed on a cylinder and revolving in a frame at the head, stern, or side of a vessel.
Other means had been also suggested prior to 1800, and by the same set of philosophers, and experimentally used by practical builders, such as steam-pumps for receiving the water forward, or amidships, and forcing it out astern, thus creating a propulsive movement. The latter part of the eighteenth century teemed with these suggestions and experiments, but it remained for the nineteenth to see their embodiment and adaptation to successful commercial use.
The earliest, most successful demonstrations of screw propellers and paddle wheels in steam vessels in the century were the construction and use of a boat with twin screws by Col. John Stevens of Hoboken, N. J., in 1804 and the paddle-wheel steamboat trial of Fulton on the Hudson in 1807.
But it was left to John Ericsson, that great Swedish inventor, going to England in 1826 with his brain full of ideas as to steam and solar engines, to first perfect the screw-propeller. He there patented in 1836 his celebrated propeller, consisting of several blades or segments of a screw, and based on such correct principles of twist that they were at once adopted and applied to steam vessels.
In 1837-1839 the knowledge of his inventions had preceded him to America, where his propeller was at once introduced and used in the vessels Frances B. Ogden and the Robert E. Stockton (the latter built by the Lairds of Birkenhead and launched in 1837). In 1839 or 1840 Ericsson went to America, and in 1841 he was engaged in the construction of the U.S. ship of war Princeton, the first naval screw warship built having propelling machinery under the water line and out of reach of shot.
The idea that steamships could not be safely run at a greater speed than ten or twelve miles an hour was now abandoned.
Twice Ericsson revolutionised the naval construction of the world by his inventions in America: first by the introduction of his screw-propeller in the Princeton; and second, by building the iron-clad Monitor.
Since Ericsson’s day other inventors have made themselves also famous by giving new twists to the tail of this famous fish and new forms to its iron-ribbed body.
Pneumatic Propellers operated by the expulsion of air or gas against the surrounding body of water, and chain-propellers, consisting of a revolving chain provided with paddles or floats, have also been invented and tested, with more or less successful results.
A great warship as she lies in some one of the vast modern ship-yards of the world, resting securely on her long steel backbone, from which great ribs of steel rise and curve on either side and far overhead, like a monstrous skeleton of some huge animal that the sea alone can produce, clothed with a skin, also of steel; her huge interior, lined at bottom with an armoured deck that stretches across the entire breadth of the vessel, and built upon this deck, capacious steel compartments enclosing the engines and boilers, the coal, the magazines, the electric plant for supplying power to various motors for lighting the ship and for furnishing the current to powerful search-lights; having compartments for the sick, the apothecary shop, and the surgeon’s hospital, the men’s and the officers’ quarters; above these the conning tower and the armoured pilot-house, then the great guns interspersed among these various parts, looking like the sunken eyes, or protruding like the bony prominences of some awful sea monster, is a structure that gives one an idea of the immense departure which has occurred during the last half century, not only from the wooden walls of the navies of all the past, but from all its mechanical arts.
What a great ocean liner contains and what the contributions are to modern ship-building from other modern arts is set forth in the following extract from McClure’s Magazine for September, 1900, in describing the Deutschland. “The Deutschland, for instance has a complete refrigerating plant, four hospitals, a safety deposit vault for the immense quantities of gold and silver which pass between the banks of Europe and America, eight kitchens, a complete post-office with German and American clerks, thirty electrical motors, thirty-six pumps, most of them of American and English make, no fewer than seventy-two steam engines, a complete drug store, a complete fire department, with pumps, hose and other fire-fighting machinery, a library, 2600 electric lights, two barber shops, room for an orchestra and brass band, a telegraph system, a telephone system, a complete printing establishment, a photographic dark room, a cigar store, an electric fire-alarm system, and a special refrigerator for flowers.”
We have seen, in treating of safes and locks, how burglars keep pace with the latest inventions to protect property by the use of dynamite and nitro-glycerine explosions. The reverse of this practice prevails when those policemen of the seas, the torpedo boats, guard the treasures of the shore. It is there the defenders are armed with the irresistible explosives. These explosives are either planted in harbours and discharged by electricity from the shore, or carried by very swift armoured boats, or by boats capable of being submerged, directed, and propelled by mechanisms contained there and controlled from the shore, or from another vessel; or by boats containing all instrumentalities, crew, and commander, and capable of submerging and raising itself, and of attacking and exploding the torpedo when and where desired. The latter are now considered as the most formidable and efficient class of destroyers.
No matter how staunch, sound and grand in dimensions man may build his ships, old Neptune can still toss them. But Franklin, a century and a half ago, called attention to his experiments of oiling his locks when in a tempestuous mood, and thus rendering the temper of the Old Man of the Sea as placid as a summer pond. Ships that had become unmanageable were thus enabled, by spreading oil on the waves from the windward side, to be brought under control, and dangerous surfs subdued, so that boats could land. Franklin’s idea of pouring oil on the troubled waters has been revived during the last quarter of the century and various means for doing it vigorously patented. The means have varied in many instances, but chiefly consist of bags and other receptacles to hold and distribute the oil upon the surrounding water with economy and uniformity.
At the close of the century the world was still waiting for the successful Air-ship.
A few successful experiments in balloon navigation by the aid of small engines of different forms have been made since 1855. Some believe that Count Zeppelin, an officer of the German army has solved the great problem, especially since the ascent of his ship made on July 2, 1900, at Lake Constance.
It has been asserted that no vessel has yet been made to successfully fly unless made on the balloon principle, and Count Zeppelin’s boat is on that principle. According to the description of Eugen Wolf, an aeronaut who took part in the ascent referred to and who published an account of the same in the November number of McClure’s, 1900, it is not composed of one balloon, but of a row of them, and these are not exposed when inflated to every breeze that blows, but enclosed and combined in an enormous cylindrical shell, 420 feet in length, about 38 feet in diameter, with a volume of 14,780 cubic yards and with ends pointed like a cigar. This shell is a framework made up of aluminium trellis work, and divided into seventeen compartments, each having its own gas bag. The frame is further strengthened and the balloons stayed by a network of aluminium wire, and the entire frame covered with a soft ramie fibre. Over this is placed a water-tight covering of pegamoid, and the lower part covered with light silk. An air space of two feet is left between the cover and the balloons. Beneath the balloons extends a walking bridge 226 feet long, and from this bridge is suspended two aluminium cars, at front and rear of the centre, adapted to hold all the operative machinery and the operator and other passengers.
The balloons, provided with proper valves, served to lift the structure; large four-winged screws, one on each side of the ship, their shafts mounted on a light framework extending from the body of the ship, and driven backward and forward by two light benzine engines, one on each car, constituted the propelling force. Dirigibility (steering) was provided for by an apparatus consisting of a double pair of rudders, one pair forward and one aft, reaching out like great fins, and controlled by light metal cords from the cars. A ballast of water was carried in a compartment under each car. To give the ship an upward or a downward movement the plane on which the ship rests was provided with a weight adapted to slip back and forth on a cable underneath the balloon shell. When the weight was far aft the tip of the ship was upward and the movement was upward, when at the forward end the movement was downward, and when at the centre the ship was poised and travelled in a horizontal plane. The trip was made over the lake on a quiet evening. A distance of three and three-quarter miles, at a height of 1300 feet, was made in seventeen minutes. Evolutions from a straight course were accomplished. The ship was lowered to the lake, on which it settled easily and rode smoothly.
The other great plan of air navigation receiving the attention of scientists and aeronauts is the aeroplane system. Although the cohesive force of the air is so exceedingly small that it cannot be relied upon as a sufficient resisting medium through which propulsion may be accomplished alone by a counter-resisting agent like propeller blades, yet it is known what weight the air has and it has been ascertained what expanse of a thin plane is necessary without other means to support the weight of a man in the air.
To this idea must be added the means of flight, of starting and maintaining a stable flight and of directing its course. Careful observation of the manner of the flight of large heavy birds, especially in starting, has led to some successful experiments. They do not rise at once, but require an initiative force for soaring which they obtain by running on the ground before spreading their wings. The action of the wings in folding and unfolding for maintaining the flight and controlling its direction, is then to be noted.
It is along these lines that inventions in this system are now working. An initiative mechanism to start the ship along the earth or water, to raise it at an angle, to spread planes of sufficient extent to support the weight of the machine and its operators on the body of the air column, light engines to give the wing-planes an opening and closing action, rudders to steer by, means for maintaining equilibrium, and means when landing to float upon the water or roll upon the land, these are the principal problems that navigators of the great seas above us are now at work upon.
CHAPTER XXX.
ILLUMINATING GAS.
“How wonderful that sunbeams absorbed by vegetation in the primordial ages of the earth and buried in its depths as vegetable fossils through immeasurable eras of time, until system upon system of slowly formed rocks have been piled above, should come forth at last, at the disenchanting touch of science, and turn the light of civilised man into day.”—Prof. E. L. Youmans.
“The invention of artificial light has extended the available term of human life, by giving the night to man’s use; it has, by the social intercourse it encourages, polished his manners and refined his tastes, and perhaps as much as anything else, has aided his intellectual progress.”—Draper.
If one desires to know what the condition of cities, towns and peoples was before the nineteenth century had lightened and enlightened them, let him step into some poor country town in some out-of-the-way region (and such may yet be found) at night, pick his way along rough pavements, and no pavements, by the light of a smoky lamp placed here and there at corners, and of weeping lamps and limp candles in the windows of shops and houses, and meet people armed with tin lanterns throwing a dubious light across the pathways. Let him be prepared to be assailed by the odours of undrained gutters, ditches, and roads called streets, and escape, if he can, stumbling and falling into them. Let him take care also that he avoid in the darkness the drippings from the overhanging eaves or windows, and falling upon the slippery steps of the dim doorway he may be about to enter. Within, let him overlook, if he can, in the hospitable reception, the dim and smoky atmosphere, and observe that the brightest and best as well as the most cheerful illuminant flashes from the wide open fireplace. Occasionally a glowing grate might be met. The eighteenth century did have its glowing grates, and its still more glowing furnaces of coal in which the ore was melted and by the light of which the castings were made.
It is very strange that year after year for successive generations men saw the hard black coal break under the influence of heat and burst into flames which lit up every corner, without learning, beyond sundry accidents and experiments, that this gast, or geest, or spirit, or vapour, or gas, as it was variously called, could be led away from its source, ignited at a distance, and made to give light and heat at other places than just where it was generated.
Thus Dr. Clayton, Dean of Kildare, Ireland, in 1688 distilled gas from coal and lit and burned it, and told his learned friend, the Hon. Robert Boyle, about it, who announced it with interest to the Royal Society, and again it finds mention in the Philosophical Transactions fifty years later. Then, in 1726, Dr. Hales told how many cubic inches of gas a certain number of grains of coal would produce. Then Bishop Watson in 1750 passed some gas through water and carried it in pipes from one place to another; and then Lord Dundonald in 1786 built some ovens, distilled coal and tar, burned the gas, and got a patent. In the same year, Dr. Rickel of Würzburg lighted his laboratory with gas made by the dry distillation of bones; but all these were experiments. Finally, William Murdock, the owner of large workshops at Redruth, in Cornwall, a practical man and mechanic, and a keen observer, using soft coal to a large extent in his shops, tried with success in 1792 to collect the escaping gas and with it lit up the shops. Whether he continued steadily to so use the gas or only at intervals, at any rate it seems to have been experimental and failed to attract attention. It appears that he repeated the experiment at the celebrated steam engine works of Boulton and Watt at Soho, near Birmingham, in 1798, and again illuminated the works in 1802, on occasion of a peace jubilee.
In the meantime, in 1801, Le Bon, a Frenchman at Paris, had succeeded in making illuminating gas from wood, lit his house therewith, and proposed to light the whole city of Paris.
Thus it may be said that illuminating gas and the new century were born together—the former preceding the latter a little and lighting the way.
Then in 1803 the English periodicals began to take the matter up and discuss the whole subject. One magazine objected to its use in houses on the ground that the curtains and furniture would be ruined by the saturation produced by the oxygen and hydrogen, and that the curtains would have to be wrung out the next morning after the illumination. There doubtless was good cause for objection to the smoky, unpleasant smelling light then produced.
In America in 1806 David Melville of Newport, Rhode Island, lighted with gas his own house and the street in front of it. In 1813 he took out a patent and lighted several factories. In 1817 his process was applied to Beaver Tail Lighthouse on the Atlantic coast—the first use of illuminating gas in lighthouses. Coal oil and electricity have since been found better illuminants for this purpose.
Murdoch, Winser, Clegg and others continued to illuminate the public works and buildings of England. Westminster Bridge and the Houses of Parliament were lighted in 1813, and the streets of London in 1815. Paris was lighted in 1820, and the largest American cities from 1816 to 1825. But it required the work of the chemists as well as the mechanics to produce the best gas. The rod of Science had touched the rock again and from the earth had sprung another servant with power to serve mankind, and waited the skilled brain and hand to direct its course.
Produced almost entirely from bituminous coal, it was found to be composed chiefly of carbon, oxygen and hydrogen; but various other gases were mixed therewith. To determine the proper proportions of these gases, to know which should be increased or wholly or partly eliminated, required the careful labours of patient chemists. They taught also how the gas should be distilled, condensed, cleaned, scrubbed, confined in retorts, and its flow measured and controlled.
Fortunately the latter part of the eighteenth century and the early part of the nineteenth had produced chemists whose investigations and discoveries paved the way for success in this revolution in the world of light. Priestley had discovered oxygen. Dalton had divided matter into atoms, and shown that in its every form, whether solid, liquid, or gaseous, these atoms had their own independent, characteristic, unalterable weight, and that gases diffused themselves in certain proportions.
Berthollet, Graham, and a host of others in England, France, and Germany, advanced the art. The highest skilled mechanics, like Clegg of England, supplied the apparatus. He it was who invented a gas purifier, liquid gas meter, and other useful contrivances.
As the character of the gas as an illuminator depends on the quantity of hydro-carbon, or olefiant elements it contains, great efforts were made to invent processes and means of carbureting it.
The manufacture of gas was revolutionised by the invention of water gas. The main principle of this process is the mixture of hydrogen with the vapour of some hydro-carbon: Hydrogen burns with very little light and the purpose of the hydro-carbon is to increase the brilliancy of the flame. The hydrogen gas is so obtained by the decomposition of water, effected by passing steam through highly heated coals.
Patents began to be taken out in this line in England in 1823-24; by Donovan in 1830; Geo. Lowe in 1832, and White in 1847. But in England water gas could not compete with coal gas in cheapness. On the contrary, in America, especially after the petroleum wells were opened up, and nature supplied the hydro-carbon in roaring wells and fountains, water gas came to the front.
The leading invention there in this line was that of T. S. C. Lowe of Morristown, Pennsylvania, in 1873. In Lowe’s process anthracite coal might be used, which was raised in a suitable retort to a great heat, then superheated steam admitted over this hot bed and decomposed into hydrogen and carbonic oxide; then a small stream of naphtha or crude petroleum was thrown upon the surface of the burning coal, and from these decompositions and mixtures a rich olefiant product and other light-giving gases were produced.
The Franklin Institute of Philadelphia in 1886 awarded Lowe, or his representatives, a grand medal of honour, his being the invention exhibited that year which in their opinion contributed most to the welfare of mankind.
A number of inventors have followed in the direction set by Lowe. The largest part of gas manufacture, which has become so extensive, embodies the basic idea of the Lowe process.
The competition set up by the electricians, especially in the production of the beautiful incandescent light for indoor illumination, has spurred inventors of gas processes to renewed efforts—much to the benefit of that great multitude who sit in darkness until corporations furnish them with light.
It was found by Siemens, the great German inventor of modern gas regenerative furnace systems, that the quality of the gas was much improved, and a greater intensity of light obtained, by heating the gases and air before combustion—a plan particularly adapted in lighting large spaces.
To describe in detail the large number of inventions relating to the manufacture of gas would require a huge volume—the generators, carburetors, retorts, mixers, purifiers, metres, scrubbers, holders, condensers, governors, indicators, registers, chargers, pressure regulators, etc., etc.
It was a great convenience outside of towns and cities, where gas mains could not be laid, to have domestic plants and portable gas apparatus, worked on the same principles, but in miniature form, adapted to a single house, but the exercise of great ingenuity was required to render such adaptation successful.
In the use of liquid illuminants, which need a wick to feed them, the Argand burner—that arrangement of concentric tubes between which the wick is confined—although invented by Argand in 1784, yet has occupied a vast field of usefulness in connection with the lamps of the nineteenth century.
A dangerous but very extensively used illuminating liquid before coal oil was discovered was camphene, distilled from turpentine. It gave a good light but was not a safe domestic companion.
Great attention has recently been paid to the production of acetylene gas, produced by the reaction between calcium carbide and water. The making of the calcium carbide by the decomposition of mixed pulverised lime and coal by the use of a powerful electric battery, is a preliminary step in the production of this gas, and was a subsequent discovery.
The electric light, acetylene, magnesium, and other modern sources of light, although they may be more brilliant and intense than coal gas, cannot compete in cheapness of production with the latter. Thus far illuminating coal gas is still the queen of artificial lights.
After gas was fairly started in lighting streets and buildings its adaptation to lamps followed; and among the most noted of gas lamps is that of Von Welsbach, who combined a bunsen gas flame and a glass chimney with a “mantle” located therein. This mantle is a gauze-like structure made of refractory quartz, or of certain oxides, which when heated by the gas flame produce an incandescent glow of intense brilliancy, with a reduced consumption of gas.
CHAPTER XXXI.
BRICK, POTTERY, GLASS, PLASTICS.
When the nineteenth century dawned, men were making brick in the same way for the most part that they were fifty centuries before. It is recorded in the eleventh chapter of Genesis that when “the whole earth was of one language and one speech, it came to pass as they journeyed from the east that they found a plain in the land of Shinar; and they dwelt there, and they said to one another, Go to, let us make brick and burn them thoroughly, And they had brick for stone, and slime had they for mortar.” Then commenced the building of Babel. Who taught the trade to the brick-makers of Shinar?
The journey from the east continued, and with it went brick making to Greece and Rome, across the continent of Europe, across the English channel, until the brick work of Cæsar, stamped by the trade mark of his legions, was found on the banks of the Thames, and through the fields of Caerleon and York.
Alfred the Great encouraged the trade, and the manufacture flourished finely under Henry VIII., Elizabeth and Charles I.
As to Pottery:—Could we only know who among the peoples of the earth first discovered, used, or invented fire, we might know who were the first makers of baked earthenware. Doubtless the art of pottery arose before men learned to bake the plastic clay, in that groping time when men, kneading the soft clay with their fingers, or imprinting their footsteps in the yielding surface and learning that the sun’s heat stiffened and dried those forms into durability, applied the discovery to the making of crude vessels, as children unto this day make dishes from the tenacious mud. But the artificial burning of the vessels was no doubt a later imitation of Nature.
Alongside the rudest and earliest chipped stone implements have been found the hollow clay dish for holding fire, or food, or water. “As the fragment of a speech or song, a waking or a sleeping vision, the dream of a vanished hand, a draught of water from a familiar spring, the almost perished fragrance of a pressed flower call back the singer, the loved and lost, the loved and won, the home of childhood, or the parting hour, so in the same manner there linger in this crowning decade of the crowning century bits of ancient ingenuity which recall to a whole people the fragrance and beauty of its past.” Prof. O. T. Mason. The same gifted writer, adds: “Who has not read, with almost breaking heart, the story of Palissy, the Huguenot potter? But what have our witnesses to say of that long line of humble creatures that conjured out of prophetic clay, without wheels or furnace, forms and decorations of imperishable beauty, which are now being copied in glorified material in the best factories of the world? In ceramic as well as textile art the first inventors were women. They quarried the clay, manipulated it, constructed and decorated the ware, burned it in a rude furnace and wore it out in a hundred uses.”
From the early dawn of human history to its present noonday civilisation the progress of man may be traced in his pottery. Before printing was an art, he inscribed on it his literature. Poets and painters have adorned it; and in its manufacture have been embodied through all ages the choicest discoveries of the chemist, the inventor and the mechanic.
It would be pleasant to trace the history of pottery from at least the time of Homer, who draws a metaphor from the potter seated before his wheel and twirling it with both hands, as he shapes the plastic clay upon it; to dwell upon the clay tablets and many-coloured vases, covered with Egyptian scenes and history; to re-excite wonder over the arts of China, in her porcelain, the production of its delicacy and bright colours wrapped in such mystery, and stagnant for so many ages, but revived and rejuvenated in Japan; to recall to mind the styles and composition of the Phœnician vases with mythological legends burned immortally therein; the splendid work of the Greek potteries; to lift the Samian enwreathed bowl, “filled with Samian wine”; to look upon the Roman pottery, statues and statuettes of Rome’s earlier and better days; the celebrated Faience (enamelled pottery) at its home in Faenza, Italy, and from the hands of its master, Luca della Robia; to trace the history of the rare Italian majolica; to tread with light steps the bright tiles of the Saracens; to rehearse the story of Bernard Palissy, the father of the beautiful French enamelled ware; to bring to view the splendid old ware of Nuremberg, the raised white figures on the deep blue plaques of Florence, the honest Delft ware of Holland; and finally to relate the revolution in the production of pottery throughout all Europe caused by the discoveries and inventions of Wedgwood of England in the eighteenth century. All this would be interesting, but we must hasten on to the equally splendid and more practical works of the busy nineteenth century, in which many toilsome methods of the past have been superseded by labour-saving contrivances.
The application of machinery to the manufacture of brick began to receive attention during the latter part of the eighteenth century, after Watt had harnessed steam, and a few patents were issued in England and America at that time for such machinery of that character, but little was practically done.
The operations in brickmaking, to the accomplishment of which by machines the inventors of the nineteenth century have devoted great talent, relate:
First, to the preparation of the clay.—In ancient Egypt, in places where water abounded, it appears that the clay was lifted from the bottoms of ponds and lakes on the end of poles, was formed into bricks, then sun-dried, modernly called adobes. The clay for making these required a stiffening material. For this straw was used, mixed with the clay; and stubble was also used in the different courses. Hence the old metaphor of worthlessness of “bricks without straw,” but of course in burning, and in modern processes of pressing unburnt bricks, straw is no longer used. Sand should abound in the clay in a certain proportion, or be mixed therewith, otherwise the clay, whether burned or unburned, will crumble. Stones, gravel and sticks must be removed, otherwise the contraction of the clay and expansion of the stones on burning, produce a weak and crumbling structure.
Brick clay generally is coloured by the oxide of iron, and in proportion as this abounds the burned brick is of a lighter or a deeper red. It may be desired to add colouring matter or mix different forms of clay, or add sand or other ingredients. Clay treated by hand was for ages kneaded as dough is kneaded, by the hand or feet, and the clay was often long subjected, sometimes for years, to exposure to the air, frost and sun to disintegrate and ripen it. As the clay must be first disintegrated, ground or pulverised, as grain is first ground to flour to make and mould the bread, so the use of a grinding mill was long ago suggested. The first machine used to do all this work goes by the humble name of pug mill.
Many ages ago the Chilians of South America hung two ponderous solid wood or stone wheels on an axis turned by a vertical shaft and operated by animal power; the wheels were made to run round on a deep basin in which ores, or stones, or grain were placed to be crushed. This Chilian mill, in principle, was adopted a century or so ago in Europe to the grinding of clay. The pug mill has assumed many different forms in this age; and separate preliminary mills, consisting of rollers of different forms for grinding, alone are often used before the mixing operation. In one modern form the pug mill consists of an inverted conical-shaped cylinder provided with a set of interior revolving blades arranged horizontally, and below this a spiral arrangement of blades on a vertical axis, by which the clay is thoroughly cut up and crushed against the surrounding walls of the mill, in the meantime softened with water or steam if desired, and mixed with sand if necessary, and when thus ground and tempered is finally pressed down through the lower opening of the cylinder and directly into suitable brick moulds beneath.
Second.—The next operation is for moulding and pressing the brick. To take the place of that ancient and still used mode of filling a mould of a certain size by the hands with a lump of soft clay, scraping off the surplus, and then dumping the mould upon a drying floor, a great variety of machines have been invented.
In some the pug mill is arranged horizontally to feed out the clay in the form of a long horizontal slab, which is cut up into proper lengths to form the bricks. Some machines are in the form of a large horizontal revolving wheel, having the moulds arranged in its top face, each mould charged with clay as the wheel presents it under the discharging spout of the grinding mill, and then the clay is pressed by pistons or plungers worked by a rocking beam, and adapted to descend and fit into the mould at stated intervals; or the moulds, carried in a circular direction, may have movable bottom plates, which may be pressed upwards successively by pistons attached to them and raised by inclines on which they travel, forcing the clay against a large circular top plate, and in the last part of the movement carrying the pressed brick through an aperture to the top of the plate, where it is met by and carried away on an endless apron.
In some machines two great wheels mesh together, one carrying the moulds in its face, and the other the presser plate plungers, working in the former, the bricks being finally forced out on to a moving belt by the action of cam followers, or by other means.
In others the moulds are passed, each beneath a gravity-descending or cam-forced plunger, the clay being thus stamped by impact into form; or in other forms the clay in the moulds may be subjected to successive pressure from the cam-operated pistons arranged horizontally and on a line with the discharging belt.
Third, the drying and burning of the brick.—The old methods were painfully slow and tedious. A long time was occupied in seasoning the clay, and then after the bricks were moulded, another long time was necessary to dry them, and a final lengthy period was employed to burn them in crude kilns. These old methods were too slow for modern wants. But they still are in vogue alongside of modern inventions, as in all ages the use of old arts and implements have continued along by the side of later inventions and discoveries.
No useful contrivances are suddenly or apparently ever entirely supplanted. The implements of the stone age are still found in use by some whose environment has deprived them of the knowledge of or desire to use better tools. The single ox pulling the crooked stick plough, or other similar ancient earth stirrer, and Ruth with her sickle and sheaves, may be found not far from the steam plough and the automatic binder.
But the use of antiquated machinery is not followed by those who lead the procession in this industrial age. Consequently other means than the slow processes of nature to dry brick and other ceramics, and the crude kilns are giving way to modern heat distributing structures.
Air and heat are driven by fans through chambers, in which the brick are openly piled on cars, the surplus heat and steam from an engine-room being often used for this purpose, and the cars so laden are slowly pushed on the tracks through heated chambers. Passages and pipes and chimneys for heat and air controlled by valves are provided, and the waste moisture drawn off through bottom drains or up chimneys, the draft of which is increased by a hot blast, or blasts of heated air are driven in one direction through a chamber while the brick are moved through in the opposite direction, or a series of drying chambers are separated from each other by iron folding-doors, the temperature increasing as cars are moved on tracks from one chamber to another.
Dr. Hoffmann of Berlin invented different forms of drying and burning chambers which attracted great attention. In his kiln the bricks are stacked in an annular chamber, and the fire made to progress from one section of the chamber to another, burning the brick as the heat advances; and as fast as one section of green brick is dried, or burned, it is withdrawn, and a green section presented. Austria introduced most successful and thorough systems of drying brick about 1870. In some great kilns fires are never allowed to cease. One kiln had been kept thus heated for fifteen years. Thus great quantities of green brick can at any time be pushed into the kiln on tracks, and when burned pushed out, and thus the process may go on continuously day and night.
To return to pottery: As before stated, Wedgwood of England revolutionised the art of pottery in the eighteenth century. He was aided by Flaxman. Before their time all earthenware pottery was what is now called “soft pottery.” That is, it was unglazed, simply baked clay; lustrous or semi-glazed and enamelled having a harder surface. Wedgwood invented the hard porcelain surface, and very many beautiful designs. To improve such earthenware and to best decorate it, are the objects around which modern inventions have mostly clustered.
The “regenerative” principle of heating above referred to employed in some kilns, and so successfully incorporated in the regenerators invented since 1850 by Siemens, Frank, Boetius, Bicheroux, Pousard and others, consisting in using the intensely hot wasted gases from laboratories or combustion chambers to heat the incoming air, and carrying the mingled products of combustion into chambers and passages to heat, dry or burn materials placed therein, has been of great service in the production of modern pottery; not only in a great saving in the amount of fuel, but in reduction in loss of pieces of ware spoiled in the firing.
The old method of burning wood, or soft coal, or charcoal at the bottom of a small old-fashioned cylindrical fire brick kiln attended to by hand, and heating the articles of pottery arranged on shelves in the chamber above, is done away with to a great extent in large manufactories for the making of stone and earthenware—although still followed in many porcelain kilns.
Inventions in the line of pottery kilns have received the aid of woman. Susan Frackelton of the United States invented a portable kiln for firing pottery and porcelain, for which she obtained a patent in 1886.
As in drying clay for brick, so in drying clay for porcelain and pottery generally, great improvements have been made in the drying of the clay, and other materials to be mixed therewith. A great step was taken to aid drying by the invention of the filter press, in which the materials, after they are mixed and while still wet, are subjected to such pressure that all surplus water is removed and all air squeezed out, by which the inclosure of air bubbles in the clay is prevented.
Despairing of excelling the China porcelain, although French investigators having alleged their discovery of such methods, modern inventors have contented themselves in inventing new methods and compositions. Charles Aoisseau, the potter of Tours, born in 1796, rediscovered and revived the art of Palissy. About 1842, Thomas Battam of England invented the method of imitating marble and other statuary by a composition of silica, alumina, soda, and traces of lime, magnesia, and iron, reducing it to liquid form and pouring it into plaster moulds, forming the figure or group. His plaster casts soon became famous. In the use of materials the aid of chemists was had in finding the proper ingredients to fuse with sand to produce the best forms of common and fine Faience.
Porcelain Moulding, and its accompanying ornamentation and the use of apparatus for moulding by compression and by exhaustion of the air has become since that time a great industry.
Porcelain Colours.—Chemists also aided in discovering what metallic ingredients could best be used when mixed with the clay and sand to produce the desired colours. As soon as a new metal was discovered, it was tested to find, among other things, what vitrifiable colour it would produce. In the production of metallic glazes, the oxides generally are employed. The colours are usually applied to ware when it is in its unglazed or biscuit form. In the biscuit or bisque form pottery is bibulous, the prepared glaze sinks into its pores and when burned forms a vitreous coating.
The application of oil colours and designs to ware before baking by the “bat” system of printing originated in the eighteenth and was perfected in the nineteenth century. It consists of impressing oil pictures on a bat of glue and then pressing the bat on to the porous unbaked clay or porcelain which transferred the colours. This was another revolution in the art.
One manner for ages of applying colours to ware is first to reduce the mixture to a liquid form, called “slip,” and then, if the Chinese method is followed, to dip the colour up on the end of a hollow bamboo rod, which end is covered with wire gauze, then by blowing through the rod the colour was sprayed or deposited on the ware. Another method is the use of a brush and comb. The brush being dipped into the coloured matter, the comb is passed over the brush in such manner as to cause the paint to spatter the object with fine drops or particles. A very recent method, by which the beautiful background and blended colours of the celebrated Rookwood pottery of Cincinnati, Ohio, have become distinguished, consists in laying the colour upon the ware in a cloud or sheet of almost imperceptible mist by the use of an air atomiser blown by the operator. By the use of this simple instrument, the laying on a single colour, or the delicate blending and shadings of two or more colours in very beautiful effects is easily produced.
This use of the atomiser commenced in 1884, and was claimed as the invention of a lady, Miss Laura Fry, who obtained a patent for thus blowing the atomised spray colouring matter on pottery in 1889; but it was held by the courts that she was anticipated by experiments of others, and by descriptions in previous patents of the spraying of paint on other objects by compressed air apparatus known as the air brush. However, this introduction of the use of the atomiser caused quite a revolution in the art of applying colours to pottery in the forming of backgrounds.
Enamelled ware is no longer confined to pottery. About 1878 Niedringhaus in the United States began to enamel sheet iron by the application of glaze and iron oxide, giving such articles a granite appearance; and since then metallic cooking vessels, bath tubs, etc., have been converted in appearance into the finest earthenware and porcelain, and far more durable, beautiful and useful than the plain metal alone for such purposes.
When we remember that for many centuries, wood and pewter, and to some extent crude earthenware, were the materials from which the dishes of the great bulk of the human family were made, as well as their table and mantel ornaments, and compare them in character and plenteousness with the table and other ware of even the poorest character of to-day, we can appreciate how much has been done in this direction to help the human family by modern inventions.
Artificial Stone.—The world as yet has not so far exhausted its supply of stone and marble as to compel a resort to artificial productions on a great scale, and yet to meet the demands of those localities wherein the natural supplies of good building stones and marble are very scarce, necessitating when used a long and expensive transportation, methods have been adopted by which, at comparatively small cost, fine imitations of the best stones and marbles have been produced, having all the durable and artistic qualities of the originals, as for the most part, they are composed of the same materials as the stone and marbles themselves.
The characteristic backgrounds, the veins and shadowings, and the soft colours of various marbles have been quite successfully imitated by treating dehydrated gypsum with various colouring solutions. Sand stones have been moulded or pressed from the same ingredients, and with either smooth or undressed faces. When necessary the mixture is coloured, to resemble precisely the original stones.
One of the improvements in the manufacture and use of modern cements and artificial stones consists in their application to the making of streets and sidewalks. Neat, smooth, hard, beautiful pavements are now taking the place everywhere of the unsatisfactory gravel, wood, and brick pavements of former days. We know that the Romans and other ancient peoples had their hydraulic cements, and the plaster on some of their walls stands to-day to attest its good quality. Modern inventors have turned their attention in recent years to the production of machines to grind, crush, mix and set the materials, and to apply them to large wall surfaces, in place of hand labour. Ready-made plaster of a fine quality is now manufactured in great quantities. It needs only the addition of a little water to reduce it to a condition for use; and a machine operated by compressed air may be had for spreading it quickly over the lath work of wood or sheet metal, slats, or over rough cement ceilings and walls.
Glass.—The Sister of Pottery is Glass. It may have been an accidental discovery, occurring when men made fire upon a sandy knoll or beach, that fire could melt and fuse sand and ashes, or sand and lime, or sand and soda or some other alkali, and with which may also have been mixed some particles of iron, or lead, or manganese, or alumina to produce that hard, lustrous, vitreous, brittle article that we call glass.
But who invented the method of blowing the viscid mass into form on the end of a hollow tube? Who invented the scissors and shears for cutting and trimming it when soft? Or the use of the diamond, or its dust, for polishing it when hard? History is silent on these points. The tablets of the most ancient days of Egypt, yet recovered, show glass blowers at work at their trade—and the names of the first and original inventors are buried in oblivion. Each age has handed down to us from many countries specimens of glass ware which will compare favourably in beauty and finish with any that can be made to-day.
Yet with the knowledge of making glass of the finest description existing for centuries, it is strange that its manufacture was not extended to supply the wants of mankind, to which its use now seems so indispensable. And yet as late as the sixteenth and seventeenth centuries glass windows were found only in the houses of the wealthy, in the churches and palaces, and glass mirrors were unknown except to the rich, as curiosities, and as aids to the scientists in the early days of telescopy. Poor people used oiled paper, isinglass, thinly shaved leather, resembling parchment, and thin sheets of soft pale crystalised stone known as talc, and soapstone.
The nineteenth century has been characterised as the scientific century of glass, and the term commercial, may well be added to that designation.
Its commercial importance and the advancement in its manufacture during the first half of the century is illustrated in the fact that the Crystal Palace of the London Industrial Exhibition of 1851, although containing nearly 900,000 square feet of glass, was furnished by a single firm, Messrs. Chance & Co. of London, without materially delaying their other orders. In addition to scientific discoveries, the manufacture of glass in England received a great impetus by the removal of onerous excise duties which had been imposed on its manufacture.
The principal improvements in the art of glass-making effected during the nineteenth century may be summarised as follows:
First, Materials.—By the investigations of chemists and practical trials it was learned what particular effect was produced by the old ingredients employed, and it was found that the colours and qualities of glass, such as clearness, strength, tenacity, purity, etc., could be greatly modified and improved by the addition to the sand of certain new ingredients. By analysis it was learned what different metallic oxides should be employed to produce different colours. This knowledge before was either preserved in secrecy, or accidentally or empirically practised, or unknown. Thus it was learned and established that lime hardens the glass and adds to its lustre; that the use of ordinary ingredients, the silicates of lime, magnesia, iron, soda and potash, in their impure form, will produce the coarser kinds of glass, such as that of which green bottles are made; that silicates of soda and lime give the common window glass and French plate; that the beautiful varieties of Bohemian glass are chiefly a silicate of potash and lime; that crystal or flint glass, so called because formerly pulverised flints were used in making it, can be made of a suitable combination of potassia plumbic silicate; that the plumbic oxide greatly increases its transparency, brilliancy, and refractive power; that paste—that form of glass from which imitations of diamonds are cut, may be produced by adding a large proportion of the oxide of lead; that by the addition of a trace of ferric oxide or uranic acid the yellow topaz can be had; that by substituting cobaltic oxide the brilliant blue sapphire is produced; that cuperic oxide will give the emerald, gold oxide the ruby, manganic oxide the royal purple, and a mixture of cobaltic and manganic oxides the rich black onyx.
Professor Faraday as early as 1824 had noticed a change in colour gradually produced in glass containing oxide of manganese by exposure to the rays of the sun. This observation induced an American gentleman, Mr. Thomas Gaffield, a merchant of Boston, to further experiment in this direction. His experiments commenced in 1863, and he subjected eighty different kinds of glass, coloured and uncoloured, and manufactured in many different countries, to this exposure of the sun’s rays. He found that not only glass having manganese as an element, but nearly every species of glass, was so affected, some in shorter and some in longer times; that this discoloration was not due to the heat rays of the sun, but to its actinic rays; and that the original colour of the glass could be reproduced by reheating the same.
Mr. Gaffield also extended his experiments to ascertain the power of different coloured glasses to transmit the actinic or chemical rays, and found that blue would transmit the most and red and orange the least.
Others proceeded on lines of investigation in ascertaining the best materials to be employed in glass-making in producing the clearest and most permanent uncoloured light; the best coloured lights for desired purposes; glasses having the best effects on the growth of plants; and the best class for refracting, dispersing and transmitting both natural lights and those great modern artificial lights, gas and electricity.
Another illustration of modern scientific investigation and success in glass-making materials is seen at the celebrated German glass works at Jena under the management of Professors Ernst Abbe and Dr. Schott, commenced in 1881. They, too, found that many substances had each its own peculiar effect in the refraction and dispersion of light, and introduced no fewer than twenty-eight new substances in glass making. Their special work was the production of glass for the finest scientific and optical purposes, and the highest grades of commercial glass. They have originated over one hundred new kinds of glass. Their lenses for telescopes and microscopes and photographic cameras, and glass and prisms, and for all chemical and other scientific work, have a worldwide reputation.
So that in materials of composition the old days in which there were substantially but two varieties of glass—the old-fashioned standard crown, and flint glass—have passed away.
Methods.—The revolution in the production of glass has been greatly aided also by new methods of treatment of the old as well as the new materials. For instance, the application of the Siemens regenerative furnace, already alluded to in referring to pottery, in place of old-fashioned kilns, and by which the amount of smoke is greatly diminished, fuel saved, and the colour of the glass improved. Pots are used containing the materials to be melted and not heated in the presence of the burning fuel, but by the heated gases in separate compartments.
Another process is that of M. de la Bastie, added to by others, of toughening glass by plunging it while hot and pasty and after it has been shaped, annealed, and reheated, into a bath of grease, whereby the rapid cooling and the grease changes its molecular condition so that it is less dense, resists breaking to a greater degree, and presents no sharp edges when broken.
Another process is that of making plate glass by the cylinder process—rolling it into large sheets.
Other processes are those for producing hollow ware by pressing in moulds; for decorating; for surface enamelling of sheet glass whereby beautiful lace patterns are transferred from the woven or netted fabric itself by using it as a stencil to distribute upon the surface the pulverised enamel, which is afterwards burned on; of producing iridescent glass in which is exhibited the lights and shadows of delicate soap bubble colours by the throwing against the surface of hydrochloric acid under pressure, or the fumes of other materials volatilised in a reheating furnace.
Then there is Dode’s process for platinising glass, by which a reflecting mirror is produced without silvering or otherwise coating its back, by first applying a thin coating of platinic choride mixed with an oil to the surface of the glass and heating the same, by which the mirror reflects from its front face. The platinum film is so thin that the pencil and hand of a draughtsman may be seen through it, the object to be copied being seen by reflection.
Again there is the process of making glass wool or silk—which is glass drawn out into such extremely fine threads that it may be used for all purposes of silk threads in the making of fabrics for decorative purposes and in some more useful purposes, such as the filtration of water and other liquids.
We have already had occasion to refer to Tilghman’s sand blast in describing pneumatic apparatus. In glass manufacture the process is used in etching on glass designs of every kind, both simple and intricate. The sand forced by steam, or by compressed air on the exposed portions of the glass on which the design rests, will cut the same deeply, or most delicately, as the hand and eye of the operator may direct.
Machines.—In addition to the new styles of furnaces, moulds and melting, and rolling mills to which we have alluded, mention may be made of annealing and cooling ovens, by which latter the glass is greatly improved by being allowed to gradually cool. A large number of instruments have been invented for special purposes, such as for making the beautiful expensive cut glass, which is flint glass ground by wheels of iron, stone, and emery into the desired designs, while water is being applied, and then polished by wheels of wood, and pumice, or rottenstone; for grinding and polishing glass for lenses; and for polishing and finishing plate glass; for applying glass lining to metal pipes, tubes, etc.; for the delicate engraving of glass by small revolving copper disks, varying in size from the diameter of a cent down to one-fifteenth of an inch, cutting the finest blade of grass, a tiny bud, the downy wing of an insect, or the faint shadow of an exquisite eyebrow.
Cameo cutting and incrustation; porcelain electroplating and moulding apparatus, and apparatus for making porcelain plates before drying and burning, may be added to the list.
It would be a much longer list to enumerate the various objects made of glass unknown or not in common use in former generations. The reader must call to mind or imagine any article which he thinks desirable to be made from or covered with this lustrous indestructible material, or any practicable form of instrument for the transmission of light, and it is quite likely he will find it already at hand in shops or instruments in factories ready for its making.
Rubber—Goodyear.
The rubber tree, whether in India with its immense trunk towering above all its fellows and wearing a lofty crown, hundreds of feet in circumference, of mixed green and yellow blossoms; or in South America, more slender and shorter but still beautiful in clustered leaves and flowers on its long, loosely pendent branches; or in Africa, still more slender and growing as a giant creeper upon the highest trees along the water courses, hiding its struggling support and festooning the whole forest with its glossy dark green leaves, sweetly scented, pure white, star-like flowers, and its orange-like fruit—yields from its veins a milk which man has converted into one of the most useful articles of the century.
The modes of treating this milky juice varies among the natives of the several countries where the trees abound. In Africa they cut or strip the bark, and as the milk oozes out the natives catch and smear it thickly over their limbs and bodies, and when it dries pull it off and cut it into blocks for transportation. In Brazil the juice is collected in clay vessels and smoked and dried in a smouldering fire of palm nuts, which gives the material its dark brown appearance. They mould the softened rubber over clay patterns in the form of shoes, jars, vases, tubes, etc., and as they are sticky they carry them separated on poles to the large towns and sea ports and sell them in this condition. It was some such articles that first attracted the attention of Europeans, who during the eighteenth century called the attention of their countrymen to them.
It was in 1736 that La Condamine described rubber to the French Academy. He afterward resided in the valley of the Amazon ten years, and then he and MM. Herissent, Macquer, and Grossat, again by their writings and experiments interested the scientific and commercial world in the matter.
In 1770 Dr. Priestley published the fact that this rubber had become notable for rubbing out pencil marks, bits of it being sold for a high price for that purpose. About 1797, some Englishman began to make water-proof varnish from it, and to take out patents for the same. This was as far as the art had advanced in caoutchouc, or rubber, in the eighteenth century.
In 1819 Mr. Mackintosh, of Glasgow, began experimenting with the oil of naphtha obtained from gas works as a solvent for India rubber; and so successfully that he made a water-proof varnish which was applied to fabrics, took out his patent in England in 1823, and thus was started the celebrated “Mackintoshes.”
In 1825 Thomas C. Wales, a merchant of Boston, conceived the idea of sending American boot and shoe lasts to Brazil for use in place of their clay models. This soon resulted in sending great quantities of rubber overshoes to Europe and America.
The importation of rubber and the manufacture of water-proof garments and articles therefrom now rapidly increased in those countries. But nothing that could be done would prevent the rubber from getting soft in summer and hard and brittle in the winter. Something was needed to render the rubber insensible to the changes of temperature.
For fifty years, ever since the manufacturers and inventors of Europe and America had learned of the water-proof character of rubber, they had been striving to find something to overcome this difficulty. Finally it became the lot of one man to supply the want. His name was Charles Goodyear.
Born with the century, in New Haven, Connecticut, and receiving but a public school education, he engaged with his father in the hardware business in Philadelphia. This proving a failure, he, in 1830, turned his attention to the improvement of rubber goods. He became almost a fanatic on the subject—going from place to place clad in rubber fabrics, talking about it to merchants, mechanics, scientists, chemists, anybody that would listen, making his experiments constantly; deeply in debt on account of his own and his father’s business failures, thrown into jail for debt for months, continuing his experiments there with philosophical, good-natured persistence; out of jail steeped to his lips in poverty; his family suffering for the necessaries of life; selling the school books of his children for material to continue his work, and taking a patent in 1835 for a rubber cement, which did not help him much. Finding that nitric acid improved the quality of the rubber by removing its adhesiveness, he introduced this process, which met with great favour, was applied generally to the manufacture of overshoes, and helped his condition. But his trials and troubles continued. Finally one Nathaniel Haywood suggested the use of sulphurous acid gas, and this was found an improvement; but still the rubber would get hard in winter, and although not so soft in summer, yet the odour was offensive. Yet by the use of this improvement he was enabled to raise more money to get Haywood a patent for it, while he became its owner. In the midst of his further troubles, and while experimenting with the sulphur mixed with rubber he found by accidental burning or partly melting of the two together on a stove, that the part in which the sulphur was embedded was hard and inelastic, and that the part least impregnated with the sulphur was proportionately softer and more elastic. At last the great secret was discovered!