Democratic Sentinel, Volume 14, Number 42, Rensselaer, Jasper County, 14 November 1890 — CHICAGO IN THE LEAD. [ARTICLE+ILLUSTRATION]

CHICAGO IN THE LEAD.

NOW CONSTRUCTING A WONDERFUL LIGHTING PLANT. A History of Illumination—The Six Eras of Light: Wood, Lamps Candles, Gas, Kerosene, and Elec riclty—Tne Electric Light, the King of Them All—The Principle Upon Which It Is Constructed— How Coal Is Turned Into an Electric Current.

HILE darkness covered the face cf the earth God said, Let there be light. Ever since the issuance of the divine command, which marked the beginning lO f time, [at least so I far as this power is ■concerned, ,light has -been regarded a s the chiefes t and

most Important of all good gifts, without which vegetable and animal life would never have had an existence. What light is wo can judge only from Its effects, its real essence remaining an impenetrable mystjerv. But this is likewise true of many other things, including life itself. Light is an incident of fire, and from the most remote ages the two have been principal among the concerns of mankind. Fire, and withit artificial light, was obtained by, the savage ancients from the effects of lightning, volcanic eruptions and spontaneous combustion. When observation and thought had developed something of the inventive talent inherent in man, he discovered that fire can be obtained as the result of friction, the principle upon which we still rely when “stricklng a match,” and had acquired the power of producing a light without the Intercession of the gods. The history of artificial illumination Is, in a certain sense, the history of the world’s progress. In the rudest times light was obtained by burning wood or other vegetable substances. After a time these gave place to oils, animal and vegetable. As light was regarded as the special gift of the divinities, lamps became early works of art, upon which great ingenuity, both as to shape and ornamentation, was expended; indeed, external form was more regarded than powers of illumination. Lamps, as devised by the ancient Hebrews, have continued in use down to our century and may still be encountered in the French portions of Canada. These are oval metallic vessels with a handle at one end and a beak at the other, through a hole in which, a wick conducts oil or grease from below, emitting a smoky light. It is difficult for us to conceive of an ago in which “tallow dips” were not employed for household illumination; indeed, it would seem that their use ought to have antedated the lamp. As a matter of fact candles are a comparatively modern invention, having been first introduced in the latter part of the thirteenth century. Originally they were made by the process of “dipping, ” with which most middle-aged country readers are familiar. Later they were cast in molds. Gapdies wore early made of wax, and latterly of sperm oil and the products of petroleum. Candles are spoken of in the English translation of the Bible; but the word should have been rendered “lamp.” Candles were a vast improvement over their immediate predecessor, the lamp, and mark the third era of Illumination. The fourth period dates from the invention of gas. The honor of this lies between Dr. Hales and the Rev. Jpnn Clayton, of 'VYakefiqld, England. In 1727 the former described a process of evolving illuminating gas from coal, while the latter accomplished it in 1739. The first

practical application of gas was effected" tn 1792 by William Murdock, who used ft for lighting his workshop, at Redruth, In Cornwall. In 1802 it was introduced In Soho foundry, near Birmingham, and In 1813 London Bridge was lighted by the then mysterious fluid. About this time, Sir Walter Scott wrote from London: “There is a madman proposing tb •tight the town with—whatdo you think? —why with smoke.” The next year its use became general in London, and in 1822 it was introduced into the United States at Boston. Natural gas, now extensively employed in this country, has been used in China, from remote ages, being convoyed through bamboo pipes from salt mines from. l K ?00 to J,QOo,feet in depth. . The next era in the history of illumination begins with the invention and general introduction of kerosenei .oil. At first it ■was extracted from bituminous coal; tout, since the general discovery of petroleum, has been manufactured from it. Though not the equal of gas, kerosene has furnished farmers and the residents of villages and small towns with a better and cheaper light than was before known In the world, and has proved an almost inestimable blessing to mankind. Glass chimneys, by the aid of which kerosene Is burned without emitting smoke, were Invented as an adjunct of the a*£and lamp, by Airne Argand, in the latter part of the eighteenth century. Lights to warn vessels off rocky and Otherwise dangerous coasts have been

maintained from time immemorial. At first they wore fed by wood, and later by coal, the later being used on the coasts of Sweden and Norway as late as the year 1846. In 1760 wax candles were first used in light-houses, those made of tallow being afterward introduced. The argand burner was introduced into England in 1785, and, in connection with the parabolic re-

flector, revolutionized light-houses. A parabolic reflector is a mirror which'follows the mathematical curve from which it takes its name. The light is placed as nearly as possible in the focus, and the rays of light, instead of being scattered by a plane reflector, are projected forward in nearly parallel lines. Locomotive headlight are made on this principle, which accounts for their power of

penetrating the darkness. In the United States the first light-houses were illuminated by tallow candles. Lard oil has long been the standard, though electric lights are now employed where a current can be obtained. This briiycs us to the sixth and last era

of illumination, upon which the world is just entering—the electric light. As to what electricity really is, we are as ignorant as we are of the nature of the nature of light. Wo speak of it as a “current,” but only as a matter of convenience, since, as a matter of fact, it may be something entirely different. To convey to the reader of limited scientific knowledge an intelligent idea of the electric light is a difficult but not hopeless task. When the terminal wires of a battery are brought together and then slightly separated, there results a bright light between them. To this light, by reason of its curved form, the name “electric arc” has been given. If the circuit is not immediately broken the ends of the wires become greatly heated and melt, dropping off in glowing globules. As they melt away the distance between them increases, and a point is reached at which the electro-motive force of the battery is no longer sufficient to maintain a icurrent across the intervening space. As tile heat thus generated is sufficient to fuse and even vaporize all known metals, the problem of rendering the electric light permanent and profitable became a most difficult one. Its solution was found in using points of carbon, which no heat can fuse but which can be vaporized. The bright arc is caused in part by the heated carbon vapor through which the current passes, and in part by the high .temperature of the carbon points themselves. .. Ast the points burn ah&y they are pushed forward |>y iineans of delicate' machinery, which comprises the most intricate part of an electric lamp, and a constant separating space is maintained. The carbon with

the positive <yitLo( the wire,bupus away, just twice jxs fast fts tlje ope at. the negative end. ‘if a bar of steel is magnetized by/rubbing it upon a natural magnet or loadstone one end becomes positive, attracting light objects and having a tendency to j oint to the north, the othef

negative, repelling such objects and pointing toward the south. These are spoken of as the “poles” of the magnet. Similar poles repel each other and dissimilar poles attract each other. The carbon into which the current flows from the battery is positive and its companion negative. There have been almost no end of electric lamps invented and ano less number of machines for supplying the necessary electric current. None of these machines can readily be described in detail, but the principle of most of them may be briefly stated. If a tar of soft iron is subjected to a current of electricity it and remains while the current continues, a magnet In most machines, these electro-magnets,as they arc termed, are employed in place ot the natural magnets formerly used. These masses of soft iron, through which a current is kept passing while in use, are made in such shapes that a complete circuit is established by means of a revolving coil of wire located between their poles, which is called an armature. It Is to revolve this armature at a high rate of speed that the power for running the generator is requited. The attractive power of the magnet tends to hold the armature in one position, and great force is necessary to revolve it. As it turns, the current is momentarily made and broken, and the electricity so generated carried off by means of brushes which rub against the armature, thus supplying the current to maintain the lights in the circuit. The current which renders the masses of soft iron magnets is supplied from the revolving armature, and is in turn drawn from them, together with all that is used to maintain the lamps in the circuit Whence this electricity comes no one can say, but that it can be so generated with-

out limit thousands of practical machines constantly attest. Such ipachiuo’ amount, in practice, to the conversion of so much coal, used ti for generating steam into a current of electricity of a certain power. .Almost a been employed in developing this system, which is still far frpm perfect. Ir» 1810 Sir Humphrey DaVy, the inventor of the safety lamp, exhibited in Paris an elaborate light j>roduced by two poices of earbon ana a powerful galvanic battery, The system described Is called the arc system; strips of metal axe used in place of carbon, and are kept from melting on burning by inclosing them in glass globes from which the air has been removed, producing a vaccuum. This system is used principally in public and private oosidences, but is not. well adaptedifor rutdoor lighting. i -<-%»»•;- The city of Chicago is engaged in constructing gigantic system for llght'iflg its streets'by means of oiqetricity.- 1 The work has bb'en three yeai'S ‘ffi pbogerss, and tlje results of the most gratifying nature. Three power houses are already in operation, and others are fast nearing completion. About 8300,000 a year is being expended, and before the beginning of the Columbus Fair the thickly populated portions of the city, embracing about fifty square miles, will have been.reclaimed from the domain of the ‘jgas syndicate” and brilliantly illuminated by means of the subtle and mysterious electric current. The comparison

between the twojmay. well be likened to the fight pfXthw stare and that t suppjied byjt&e iuoon ; when atythe fullj on 3a clear night.' Not only is'Chicago tlffi first large city in America to build an electric plant for itself, but it has solved the problem of placing conducting Mfifts under ground, thus avoiding alfi.thg numerous accidents ahd 'great lo&s or life which have rendered electric lighting a nuisance in New York. r The wires, 'Which'are of topper, are covered with paraffine, then with rubber, and, lastly, encased in lead pipes. The lead pipes are inclosed in others of iron, where only one line is laid-tn a street, and in large pnesof cement, with various separate passages, where a numbet are run uow'n a street to supply a distant district. About one horse-power is required for a lamp, which is of 2,000 candlepower, thirty-five being in u circuit. One lamp is placed at each street intersection, and one in the center of long blocks. In the sand-fly season the electric lamps attract the insects in vast numbers, to the intense annoyance of passers by and the amusement of onlookers. Second in nothing, the Garden City will soon, be the best and cheapest-lighted city in the world, optic-jdazzling Paris not being excepted. Dwight Baldwin. Chicago, 111. -.. IT is said that money can never give happiness. This is an experiment, however, that every man wishes to try for himself.

SAVAGE PRODUCING FIRE BY FRICTION OF WOOD.

THIS OLD JEWISH LAMP.

GASLIGHT.

ELECTRIC LIGHT.

THE SIX ERAS OF ILLUMINATION.

SAND-FLY SEASON.