Tis

HE picture at the bottom of this page is a photograph of the Tower Bridge, crossing the Thames at the Tower of London. The picture on the opposite page is a photograph of a model of this bridge made of Crane products from a copy of the photograph shown below. The proportions of the bridge were taken from an ordinary picture postal card, and the model was made at the Bridgeport Division Works of Crane Co. with material taken from regular stock.

The model is approximately nineteen feet long, eleven feet high and four feet wide. The spans are fifty-seven inches. The lifts are twenty-two inches long and thirty inches wide. The elevators in the towers are six inches square and eight inches high. These measurements will serve to give an idea of size and proportion.

Fifteen thousand three hundred and fiftyeight pieces taken from regular stock, comprising two hundred and thirty different kinds of elbows, tees, crosses, nipples, valves, etc., were used in building the model. Sixteen thousand two hundred and fifty-one joints were required to make up the fittings, and it is worthy of note that

not one left-hand thread was used in the entire construction.

The towers are neat in construction and well proportioned, having four spires, one on each corner. The spires are formed of malleable iron reducers, caps and cast iron flange unions. In each tower is an elevator. The upper part of the elevator cage is made of a brass floor flange with a plug screwed in, and with this the cable used for operating the elevator is fastened. The men operating the elevators are represented by reducers, nipples and caps. The cables connecting the towers to the approaches are made up of nipples, tees, and 45° elbows. Each approach is provided with two clocks bearing the name clocks bearing the name "Crane-Bennett Ltd."

The bridge lifts and tower elevators are raised and lowered by specially devised machinery. The reversing is done by a unique mechanical movement, and no clutches are used in its construction. The bridge is lighted by thirty-six electric lamps, eight being red and green for controlling traffic; four of these are for navigation and four for traffic on the bridge. When the bridge is closed the red light

flashes and the green light goes out to show that the bridge is closed to navigation. At the same time the green light signals open traffic on the bridge. When the bridge is open for navigation, the green light flashes to river traffic and the red light signals that bridge traffic is closed. Eight hundred feet of wire were used to carry out the electrical effect.

In the sidewalks there are 1,600 right hand close nipples together with numerous galvanized tees, crosses and elbows. This bit of construction has prompted speculation as to how the elbows, tees and crosses were made up with standard right-hand close nipples, each fitting being not more than one-sixteenth of an inch from its neighbor at the joints. The curb separating the sidewalks from the roadbed is made of galvanized nipples slotted and slipped over a tongue which holds an amber glass roadbed. The bridge is mounted on skids covered with Cranite packing painted a wavy green. When looking through the amber glass onto the green Cranite packing, a good effect of moving water is produced.

The shades on the arc lamps are made of galvanized malleable iron reducing nipples. For a time before being shipped to its permanent home with Crane-Bennett Ltd., London, the model was exhibited in the New York Show Room of Crane Co., in Forty-fourth Street, where it was a center of uncommon interest not only because of

its size and well sustained proportions, but because of the thousands of screwed joints and the practically unvarying trueness of alignment and direction, according to the line or angle for which the fittings are designed in regular installations. As the Pathé Weekly News was given permission to exhibit pictures of this model, doubtless it has been seen by some of our readers in the moving picture houses.

The Tower Bridge, of the bascule type, was opened in 1894, and at the time of its construction it was the largest bridge in the world of the bascule class. The bridge may be described as a combination suspension and bascule bridge of three spans, of which the center opening is fitted with a bascule, or drawbridge. The bascule is carried by two massive Gothic towers from which the chains or links are suspended, and in which provision is made for the machinery required for opening and closing the middle span. Elevators at both sides, as well as internal staircases are provided for the use of foot-passengers. The elevators communicate immediately with the upper footway connecting the towers so that the foot traffic is never interrupted. The leaves of the drawbridge, when open, are flush with the towers, allowing the largest shipping to pass through. When the bridge is closed there is sufficient height at high water for the ordinary traffic of the river to pass under.

T

HALES, one of the seven wise men of Greece, walked in the groves of Miletus, surrounded by his pupils. As he looked dreamily over the Egean Sea or caught in the distance a glimpse of the Meander, he builded the fabric of his Ionic philosophy and tried to discover in something physical the Great First Cause.

Mechanically he rubbed a piece of amber on a fold of his robe till it gave off perceptible warmth. It fell from his fingers to the ground, and as he stooped to pick it up, he noticed that it was covered with particles of light material which clung to it as though. it had been covered with some adhesive substance.

Pausing in his discourse, as his pupils gathered around him, he carefully wiped the amber, rubbed it again and held it near to the ground. To his intense surprise he saw the light particles flying to meet it and clinging there by some subtle and unknown force. Thales did not give to this force a name, but today it is known as statical or frictional electricity. This is the first recorded instance of a manifestation of that wonderful force which now seems to permeate every atom of created matter.

Derivation of Electricity

Our word "electricity" comes from "electron," the Greek word for amber. And all this happened 550 years before Christ, just after Jerusalem had fallen into the hands of Nebuchadnezzar and while Daniel was translating "Mene, Mene, Tekel," for Belshazzar.

Two thousand three hundred years after Thales had fallen asleep with his fathers, Signora Galvani prepared her a dish of frog's legs. She was ailing and her husband, Luigi Galvani, versed in the art of Galen and the mysteries of Esculapius, advised a

dish of frog's legs as suited to tempt her wayward palate. wayward palate. But Signora Galvani could not eat the frog's legs and she brought the dish into her husband's laboratory, fancying that soon her appetite might

return.

Galvani's assistant thoughtlessly touched one of the fried legs with a scalpel. It quivered and kicked as though full of life. Again and again the experiment was tried, Galvani watching the remarkable manifestation with wonder he made no effort to conceal. Shortly after he advanced his theory of galvanism, or dynamic electricity. Galvani reasoned that the influence which caused the quivering of the dead frog's muscles was present in all animal tissues.

The Galvanic Battery

Volta took the matter up at this point and worked on the theory that the phenomenon was due to contact of dissimilar substances, and believed he amply demonstrated this by constructing the voltaic pile or galvanic battery. Fabrioni a few years later enunciated the present or chemical theory of dynamic electricity. Davey and Faraday enlarged on this, and Oersted, in 1819, discovered, after much experimenting, electro-magnetism. Thus we have the three kinds of electricity recognized by science-statical, dynamic, and electromagnetic.

Long before the then little known force of electricity was put to any practical purpose speculative minds looked far into the future and dimly outlined many of the wonderful things to which men of today have harnessed the most subtle of Nature's energies. Strada, the Jesuit, more than two hundred years ago conceived the notion of communication by magnetism, which may be considered the starting point of practical ideas in connection with the electric

wrote:

If ancient fame the truth unfold,

Two faithful needles, from the informing touch
Of the same parent stone, together drew
Its mystic virtue, and at last conspired
With fatal impulse quivering at the pole;
Then, though disjoined by kingdoms, though the main
Rolled its broad surge betwixt, and different stars
Beheld their wakeful motions, yet preserved
The former friendship, and remembered still
The alliance of their birth. Whate'er the line
Which one possessed, nor pause nor quiet knew
The sure associate, ere with trembling speed
He found its path, and fixed unerring there.

The very vagueness of this verse shows what slight grasp Akenside had of the dream which Strada may have seen with greater clearness. But the poet's lines were quickly prophetic. In 1753 there appeared an article in the Scots Magazine describing how communication might be made through the use of static electricity-the practical application of the force beginning in the same order as the theoretical had developed.

This device was to consist of a wire for each letter of the alphabet. At each end of every wire was to be fastened a pith ball. When one of these was rubbed, its fellow at the other end of the wire, it was figured, would show sympathetic agitation produced by the current passing along or through the wire. It is not known who wrote the article, giving this description, but in 1774 Lesage of Geneva constructed the first electric telegraph on similar principles. He used twenty-four wires and produced his vibrations by friction.

In 1816 Ronalds of England constructed the first line with a single wire. (And in parenthesis it may be said that he laid his scheme before the admiralty officials, urging the use of his telegraph, and was met by the lofty dictum that "Telegraphs of any sort were wholly unnecessary." These same lords lived long enough to feel. ashamed of their dull judgment.)

In 1828 Harrison Gray Dyar of New York invented a single wire telegraph which recorded impressions on moistened litmus paper by means of needles. In 1830 Baron Schilling and Ampere suggested the use of the galvanic current and needles. Cooke improved on this, and in 1835 the first actual telegraph line was built between Paddington and Drayton, England. It

was thirteen miles long and consisted of six wires laid in iron pipes along the ground and was operated by five magnetic needles at each end of the line. By the way, slightly to digress again, why have we adopted O'Shaughnessy's method of stringing wires in Calcutta on bamboo poles, when Cooke showed what we consider the newer and better plan of using conduits in the first electric telegraph line ever built?

The Modern Telegraph

Then comes Morse with his improved instruments and alphabet, which first made the electric telegraph really practical. In 1844 the first public line in the United States was built from Washington to Baltimore under the Morse system. O'Shaughnessy laid the first submarine cable in India. J. J. Craven of Newark invented the gutta percha process for covering wire in 1847, and Alfred Vail, another New Jersey man, invented the printing telegraph. In 1858 Cyrus Field laid the Atlantic cable, over which Old Thales might have flashed a message that if there were any physical thing constituting or embodying the single first cause, he would be justified in calling it electricity.

Later names connected with new discoveries in electricity were Professor Elisha Gray, of Chicago, with his harmonic process; Farmer and the multiple process by a revolving synchronous commutator; Brush, Edison, Thomson, Houston, and Jablochoff, in lighting and power; and Dr. Alexander Graham Bell with the wonderful telephone. But the list of notable names and notable inventions and improvements in this vast field is practically endless, and is being added to every day. Electricity may be called still a stripling. Who would be bold enough to try to gauge its full

stature?

A Message from Thales

Sleep on, O, Thales! Little did you dream that the rubbing of a piece of amber would one day result in girdling the world. with thought swift in transit as the lightning's flash! Rest, Galvani and Volta, and Strada, and Fabrioni! The world honors you today for what you dreamed and what you did. And as we flash a message over the wires that span the centuries, may we

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not stand at the sounder and catch this answer:

"To the wizards of the Nineteenth and Twentieth centuries, Thales sends greeting: I have rounded my Ionic principles. I have found the first cause. It is not physical. It is psychic. Great is Electricity, mighty son of Electron, but far greater is the godlike mind that has chained him to the wheels of commerce, to Phaeton's chariot; that has made him soar higher than Pegasus ever did; that has sent him over ocean beds, through trackless wastes, and across mighty continents. Thales, the ancient, bows to the humblest son of the Electric Age as being far more blest than was the greatest philosopher of olden days."