按键盘上方向键 ← 或 → 可快速上下翻页，按键盘上的 Enter 键可回到本书目录页，按键盘上方向键 ↑ 可回到本页顶部！
————未阅读完？加入书签已便下次继续阅读！
rked for Edison。
The turbine （from the Latin turbo； meaning a whirlwind） is the name of the motor which drives the great dynamos for the generation of electric energy。 It may be either a steam turbine or a water turbine。 The steam turbine of Curtis or Parsons is today the prevailing engine。 But the development of hydro…electric power has already gone far。 It is estimated that the electric energy produced in the United States by the utilization of water powers every year equals the power product of forty million tons of coal； or about one…tenth of the coal which is consumed in the production of steam。 Yet hydro…electricity is said to be only in its beginnings； for not more than a tenth of the readily available water power of the country is actually in use。
The first commercial hydro…station for the transmission of power in America was established in 1891 at Telluride； Colorado。 It was practically duplicated in the following year at Brodie； Colorado。 The motors and generators for these stations came from the Westinghouse plant in Pittsburgh； and Westinghouse also supplied the turbo…generators which inaugurated； in 1895； the delivery of power from Niagara Falls。
CHAPTER X。 THE CONQUEST OF THE AIR
The most popular man in Europe in the year 1783 was still the United States Minister to France。 The figure of plain Benjamin Franklin； his broad head； with the calm； shrewd eyes peering through the bifocals of his own invention； invested with a halo of great learning and fame； entirely captivated the people's imagination。
As one of the American Commissioners busy with the extraordinary problems of the Peace； Franklin might have been supposed too occupied for excursions into the paths of science and philosophy。 But the spaciousness and orderly furnishing of his mind provided that no pursuit of knowledge should be a digression for him。 So we find him； naturally； leaving his desk on several days of that summer and autumn and posting off to watch the trials of a new invention； nothing less indeed than a ship to ride the air。 He found time also to describe the new invention in letters to his friends in different parts of the world。
On the 21st of November Franklin set out for the gardens of the King's hunting lodge in the Bois de Boulogne； on the outskirts of Paris； with a quickened interest； a thrill of excitement； which made him yearn to be young again with another long life to live that he might see what should be after him on the earth。 What bold things men would attempt！ Today two daring Frenchmen； Pilatre de Rozier of the Royal Academy and his friend the Marquis d'Arlandes； would ascend in a balloon freed from the earththe first men in history to adventure thus upon the wind。 The crowds gathered to witness the event opened a lane for Franklin to pass through。
At six minutes to two the aeronauts entered the car of their balloon； and； at a height of two hundred and seventy feet； doffed their hats and saluted the applauding spectators。 Then the wind carried them away toward Paris。 Over Passy； about half a mile from the starting point； the balloon began to descend； and the River Seine seemed rising to engulf them； but when they fed the fire under their sack of hot air with chopped straw they rose to the elevation of five hundred feet。 Safe across the river they dampened the fire with a sponge and made a gentle descent beyond the old ramparts of Paris。
At five o'clock that afternoon； at the King's Chateau in the Bois de Boulogne； the members of the Royal Academy signed a memorial of the event。 One of the spectators accosted Franklin。
〃What does Dr。 Franklin conceive to be the use of this new invention？〃
〃What is the use of a new…born child？〃 was the retort。
A new…born child； a new…born republic； a new invention： alike dim beginnings of development which none could foretell。 The year that saw the world acknowledge a new nation； freed of its ancient political bonds； saw also the first successful attempt to break the supposed bonds that held men down to the ground。 Though the invention of the balloon was only five months old； there were already two types on exhibition： the original Montgolfier； or fireballoon； inflated with hot air； and a modification by Charles； inflated with hydrogen gas。 The mass of the French people did not regard these balloons with Franklin's serenity。 Some weeks earlier the danger of attack had necessitated a balloon's removal from the place of its first moorings to the Champ de Mars at dead of night。 Preceded by flaming torches； with soldiers marching on either side and guards in front and rear； the great ball was borne through the darkened streets。 The midnight cabby along the route stopped his nag； or tumbled from sleep on his box； to kneel on the pavement and cross himself against the evil that might be in that strange monster。 The fear of the people was so great that the Government saw fit to issue a proclamation； explaining the invention。 Any one seeing such a globe； like the moon in an eclipse； so read the proclamation； should be aware that it is only a bag made of taffeta or light canvas covered with paper and 〃cannot possibly cause any harm and which will some day prove serviceable to the wants of society。〃
Franklin wrote a description of the Montgolfier balloon to Sir Joseph Banks； President of the Royal Society of London：
〃Its bottom was open and in the middle of the opening was fixed a kind of basket grate； in which faggots and sheaves of straw were burnt。 The air； rarefied in passing through this flame； rose in the balloon； swelled out its sides； and filled it。 The persons； who were placed in the gallery made of wicker and attached to the outside near the bottom； had each of them a port through which they could pass sheaves of straw into the grate to keep up the flame and thereby keep the balloon full 。 。 。 。 One of these courageous philosophers； the Marquis d'Arlandes； did me the honor to call upon me in the evening after the experiment； with Mr。 Montgolfier； the very ingenious inventor。 I was happy to see him safe。 He informed me that they lit gently； without the least shock； and the balloon was very little damaged。〃
Franklin writes that the competition between Montgolfier and Charles has already resulted in progress in the construction and management of the balloon。 He sees it as a discovery of great importance； one that 〃may possibly give a new turn to human affairs。 Convincing sovereigns of the folly of war may perhaps be one effect of it； since it will be impracticable for the most potent of them to guard his dominions。〃 The prophecy may yet be fulfilled。 Franklin remarks that a short while ago the idea of 〃witches riding through the air upon a broomstick and that of philosophers upon a bag of smoke would have appeared equally impossible and ridiculous。〃 Yet in the space of a few months he has seen the philosopher on his smoke bag； if not the witch on her broom。 He wishes that one of these very ingenious inventors would immediately devise means of direction for the balloon； a rudder to steer it； because the malady from which he is suffering is always increased by a jolting drive in a fourwheeler and he would gladly avail himself of an easier way of locomotion。