CHAPTER VI

THE TWENTIETH-CENTURY OUTLOOK

Air-ships.--The aeroplane.--How the Wright aeroplane is kept afloat.--Submarines.--Some spinning tops that are useful.--The monorail-car.--Liquid air and the greatest cold.--The electric furnace and the greatest heat.--The wireless telegraph.--The wireless telephone.--Wonders of the alternating current.--X-rays and radium

APPENDIX

Brief notes on important inventions

INDEX

ILLUSTRATIONS

FIG.

MARCONI WIRELESS-TELEGRAPH STATION, CLIFDEN, IRELAND THE SAME STATION PHOTOGRAPHED BY DAYLIGHT

1--THE BATTLE OF SYRACUSE

2--GALILEO'S PENDULUM CLOCK

3--AN AIR THERMOMETER

4--TORRICELLI'S EXPERIMENT

5--GUERICKE'S AIR-PUMP

6--GUERICKE'S WATER BAROMETER

7--A LIFT-PUMP

8--A SIMPLE HYDRAULIC PRESS

9--HOW AN HYDRAULIC PRESS WORKS

10--AN HYDRAULIC PRESS WITH BELT-DRIVEN PUMP

11--NEWTON'S EXPERIMENT WITH THE PRISM

12--PAPIN'S ENGINE

13--THE NEWCOMEN ENGINE, IN REPAIRING WHICH WATT WAS LED TO HIS GREAT DISCOVERIES

14--CYLINDER OF WATT'S STEAM-ENGINE

15--A FLY-BALL GOVERNOR

16--A LEYDEN JAR

17--FRANKLIN'S KITE EXPERIMENT

18--VOLTA EXPLAINING HIS ELECTRIC BATTERY TO NAPOLEON BONAPARTE

19--THE FIRST ELECTRIC BATTERY

20--COUNT RUMFORD'S EXPERIMENT WITH THE CANNON, MAKING WATER BOIL WITHOUT FIRE

21--OERSTED'S EXPERIMENT

22--A COIL WITH A CURRENT FLOWING THROUGH IT ACTS LIKE A MAGNET

23--A BAR OF SOFT IRON WITH A CURRENT FLOWING AROUND IT BECOMES A MAGNET

24--TWO COILS WITH CURRENTS FLOWING IN THE SAME DIRECTION ATTRACT EACH OTHER

25--TWO COILS WITH CURRENTS FLOWING IN OPPOSITE DIRECTIONS REPEL EACH OTHER

26--ARAGO'S EXPERIMENT

27--ONE POLE OF A MAGNET SPINS ROUND A WIRE THROUGH WHICH AN ELECTRIC CURRENT FLOWS

28--WHEN A MAGNET IS THRUST INTO A COIL OF WIRE IT CAUSES A CURRENT TO FLOW IN THE COIL, BUT THE CURRENT FLOWS ONLY WHILE THE MAGNET IS MOVING

29--A COIL OF WIRE AROUND A COMPASS-NEEDLE

30--FARADAY'S INDUCTION-COIL

31--HISTORICAL APPARATUS OF FARADAY IN THE ROYAL INSTITUTION

32--FARADAY'S FIRST DYNAMO

33--FARADAY'S LABORATORY, WHERE THE FIRST DYNAMO WAS MADE

34--THE FIRST TRANSFORMER

35--THE "MAGNETIC FIELD" IS THE SPACE AROUND A MAGNET IN WHICH IT WILL ATTRACT IRON

36--MAGNETIC FIELD OF A HORSESHOE MAGNET

37--A DANIELL CELL

38--A GRAVITY CELL

39--SHOWING WHAT IS IN A DRY BATTERY

40--A STORAGE BATTERY, SHOWING THE "GRIDS"

41--A STORAGE-BATTERY PLATE MADE FROM A SHEET OF LEAD

42--STURGEON'S ELECTROMAGNET

43--AN ELECTROMAGNET WITH MANY TURNS OF INSULATED WIRE

44--AN ELECTROMAGNET LIFTING TWELVE TONS OF IRON

45--A DYNAMO WITH SIEMENS' ARMATURE

46--RING ARMATURE

47--FIRST DYNAMO PATENTED IN THE UNITED STATES

48--A DRUM ARMATURE, SHOWING HOW AN ARMATURE OF FOUR COILS IS WOUND

49--A SERIES-WOUND DYNAMO

50--A SHUNT-WOUND DYNAMO

51--A COMPOUND-WOUND DYNAMO

52--ONE OF EDISON'S FIRST DYNAMOS

53--A DYNAMO MOUNTED ON THE TRUCK OF A RAILWAY CAR

54--FIRST ELECTRIC LOCOMOTIVE

55--FIRST EDISON ELECTRIC LOCOMOTIVE

56--EDISON'S FIRST PASSENGER LOCOMOTIVE

57--FIRST COMMERCIAL ELECTRIC RAILWAY

58--EDISON, AMERICA'S GREATEST INVENTOR, AT WORK IN HIS LABORATORY

59--EDISON'S FAMOUS HORSESHOE PAPER-FILAMENT LAMP OF

60--FIRST COMMERCIAL EDISON ELECTRIC-LIGHTING PLANT; INSTALLED ON THE STEAMSHIP "COLUMBIA" IN MAY,

61--A TELEGRAPH SOUNDER

62--MORSE'S FIRST TELEGRAPH INSTRUMENT

63--A TELEGRAPHIC CIRCUIT WITH RELAY AND SOUNDER

64--A SIMPLE TELEGRAPHIC CIRCUIT

65--FIRST TELEGRAPH INSTRUMENT USED FOR COMMERCIAL WORK

66--HOW TWO MESSAGES ARE SENT OVER ONE WIRE AT THE SAME TIME

67--HOW TWO MESSAGES ARE SENT OVER ONE WIRE AT THE SAME TIME. BRIDGE METHOD

68--FIRST BELL TELEPHONE RECEIVER AND TRANSMITTER

69--A TELEPHONE RECEIVER

70--TWO RECEIVERS USED AS A COMPLETE TELEPHONE

71--CARBON-DUST TRANSMITTER

72--THE PHONAUTOGRAPH, A FORERUNNER OF THE PHONOGRAPH

73--EDISON'S FIRST PHONOGRAPH AND A MODERN INSTRUMENT

74 to--THE FOUR-CYCLE GAS-ENGINE

78--TWO-CYCLE GAS-ENGINE. CRANK AND CONNECTING-ROD ARE ENCLOSED WITH THE PISTON

79--SELDEN "EXPLOSION BUGGY," FORERUNNER OF THE MODERN AUTOMOBILE

80--SOME EARLY LOCOMOTIVES

81--HOW A LOCOMOTIVE WORKS

82--HERO'S ENGINE

83--AN UNDERSHOT WATER-WHEEL WITH CURVED BLADES

84--AN OVERSHOT WATER-WHEEL

85--DE LAVAL STEAM-TURBINE

86--A MODERN STEAM-TURBINE WITH TOP CASING RAISED SHOWING BLADES

87--DIAGRAM OF TURBINE SHOWN IN FIG.

88--A STEAM-TURBINE THAT RUNS A DYNAMO GENERATING 14,000 ELECTRICAL HORSE-POWER

89--BRITISH ARMY AIR-SHIP "NULLI SECUNDUS" READY FOR FLIGHT

90--BASKET, MOTOR, AND PROPELLER OF THE BRITISH ARMY AIR-SHIP "NULLI SECUNDUS"

91--A ZEPPELIN AIR-SHIP

92--COUNT ZEPPELIN'S "DEUTSCHLAND," THE FIRST AIR-SHIP IN REGULAR PASSENGER SERVICE

93--THE BALDWIN AIR-SHIP USED IN THE UNITED STATES ARMY

94--IN FULL FLIGHT

95--WRIGHT AIR-SHIP IN FLIGHT

96--HOW THE WRIGHT AIR-SHIP IS KEPT AFLOAT

97--THE SEAT AND MOTOR OF THE WRIGHT AEROPLANE

98--THE BLÉRIOT MONOPLANE

99--THE "PLUNGER"

100--U. S. SUBMARINE "SHARK" READY FOR A DIVE

101--FIRST SUBMARINE CONSTRUCTED IN THE UNITED STATES. IT WENT TO THE BOTTOM WITH SEVEN MEN, WHO WERE DROWNED

102--HOW MEN IN A SUBMARINE SEE WHEN UNDER THE WATER

103--A TOP THAT SPINS ON A STRING

104--A CAR THAT RUNS ON ONE RAIL

105--MANUFACTURING DIAMONDS--FIRST OPERATION

106--MANUFACTURING DIAMONDS--SECOND OPERATION

107--MANUFACTURING DIAMONDS--THIRD OPERATION

108--MARCONI AND HIS WIRELESS-TELEGRAPH SENDING AND RECEIVING INSTRUMENTS

109--DIAGRAM OF WIRELESS-TELEGRAPH SENDING APPARATUS

110--DIAGRAM OF MARCONI WIRELESS-TELEGRAPH RECEIVING APPARATUS

111--RECEIVER OF BELL'S PHOTOPHONE

112--A GAS FLAME IS SENSITIVE TO ELECTRIC WAVES

113--CAPTAIN INGERSOLL ON BOARD THE U. S. BATTLE-SHIP "CONNECTICUT" USING THE WIRELESS TELEPHONE

114--INCANDESCENT ELECTRIC LAMP LIGHTED THOUGH NOT CONNECTED TO ANY BATTERY OR DYNAMO

115--AN ELECTRIC DISCHARGE AT A PRESSURE OF 12,000,000 VOLTS, A CURRENT OF 800 AMPERES IN THE SECONDARY COIL

116--AN ELECTRIC DISCHARGE SIXTY-FIVE FEET IN LENGTH

117--A PHYSICIAN EXAMINING THE BONES OF THE ARM BY MEANS OF X-RAYS

118--X-RAY PHOTOGRAPH OF THE EYE

119--PHOTOGRAPH MADE WITH RADIUM

INTRODUCTORY NOTE

Great inventions are a never-failing source of interest to all of us, and particularly to the boy in his teens. The dynamo, the electric motor, the telegraph, with and without wires, the telephone, air-ships, and many other inventions excite in him an interest which is deeper than mere curiosity. He wants to know how these things work, and how they were invented. The man is so absorbed in the present that he cares little for the past. Not so with the boy. He cares for the history of inventions, and in this he is wiser than the man, for it is only by a study of its origin and growth that we can understand the larger significance of a great invention.

Great inventions have their origin in great discoveries. The story of great inventions, therefore, includes the story of the discoveries out of which they have arisen. The stories of the discoveries and the inventions are inseparable from the lives of the men who made them, and so we must deal with biography, which in itself is of interest to the boy. Such a story is the story of physical science in the service of humanity.

The interest of the youth in great inventions is unquestioned. Shall we stifle this interest by overemphasis of technical detail, or shall we minister to it as a thing vital in the life of the youth of to-day?

A few sentences quoted from G. Stanley Hall will indicate the author's point of view. "The youth is in the humanist stage. Nature is sentiment before it becomes idea or formula or utility." "The heroes and history epochs of each branch [of science] add another needed quality to the still so largely humanistic stage." "A new discovery, besides its technical record, involves the added duty of concise and lucid popular statement as a tribute to youth." The need of a "concise and lucid popular statement" of the rise of the great inventions which form the material basis of our modern civilization and all of which are new to the young mind, has no doubt been keenly felt by others as it has been by the author. The story of our great inventions has been told in sundry volumes for adult readers, but nowhere has this story, alive with human interest, been told in a form suited to the young. It was the realization of this need growing out of years of experience in teaching these branches that led the author to attempt the task of writing the story.

The purpose of this book is to tell in simple language how our great inventions came into being, to depict the life-struggles of the men who made them, and, in the telling of the story, to explain the working of the inventions in a way the boy can understand. The stories which are here woven together present the great epochs in the history of physics, and are intended to give to the young reader a connected view of the way in which our great inventions have arisen out of scientific discovery on the one hand, and conditions which we may call social and economic on the other hand. If the book shall appeal to young readers, and lead them to an appreciation of the meaning of a great invention, the author will feel that his purpose has been achieved.

The author is deeply indebted to Dr. Charles A. McMurry and Prof. Newell D. Gilbert, of the Northern Illinois State Normal School; Profs. C. R. Mann and R. A. Millikan, of the University of Chicago; and Prof. John F. Woodhull, of Columbia University, for reading the manuscript and offering valuable suggestions. Acknowledgment is further made here of valuable aid in collecting material for illustrations and letter-press. Such acknowledgment is due to Prof. A. Gray, University of Glasgow; Prof. Antonio Favaro, Royal University of Padua; Prof. A. Zammarchi, Brescia, Italy; Mr. Nikola Tesla; the Royal Institution, London; _McClure's Magazine_; _The Technical World Magazine_; _The Scientific American_; the Ellsworth Company; Commonwealth-Edison Company; Association of Edison Illuminating Companies; Electric Controller and Supply Company; Kelley-Koett Manufacturing Company; Watson-Stillman Company; Gould Storage Battery Company; Thordarson Electric Company; the Westinghouse Machine Company; Marconi Wireless Telegraph Company of America, and the Siemens-Schuckert Werke, Berlin.

The drawings illustrating Faraday's experiments are from exact reproductions of Faraday's apparatus, made by Mr. Joseph G. Branch, author of _Conversations on Electricity_, and are reproduced by his kind permission.

E. E. B.

CHICAGO, _June, 1910_.

THE STORY OF GREAT INVENTIONS