CHAPTER IX

THE NEWEST ELECTRIC LIGHT 293

Peter Cooper Hewitt and his Three Great Inventions --The Mercury Arc Light--The New Electrical Converter--The Hewitt Interrupter.

LIST OF ILLUSTRATIONS

Page Guglielmo Marconi _Frontispiece_

M. Curie Explaining the Wonders of Radium at the Sorbonne 5

Dr. Danlos Treating a Lupus Patient with Radium at the St. Louis Hospital, Paris 13

Radium as a Test for Real Diamonds 19

_At the approach of Radium pure gems are thrown into great brilliancy, while imitations remain dull._

M. and Mme. Curie Finishing the Preparation of some Radium 25

M. Alberto Santos-Dumont 29

Severo's Balloon, the "Pax," which on its First Ascent at a Height of about 2,000 feet, Burst and Exploded, Sending to a Terrible Death both M. Severo and his Assistant 33

The Trial of Count Zeppelin's Air-Ship, July 2, 1900 37

M. Santos-Dumont at Nineteen 41

M. Santos-Dumont's First Balloon (Spherical) 43

M. Santos-Dumont's Workshop 45

"Santos-Dumont No. 1" 49

Basket of "Santos-Dumont No. 1" 52

_Showing propeller and motor._

"Santos-Dumont No. 1" 54

_Showing how it began to fold up in the middle._

"Santos-Dumont No. 5" Rounding Eiffel Tower, July 13, 1901 57

The Interior of the Aërodrome 61

_Showing its construction, the inflated balloon, and the pennant with its mystic letters._

The Fall into the Courtyard of the Trocadero Hotel 65

"_Santos-Dumont No. 5._"

"Santos-Dumont No. 6"--The Prize Winner 69

Air-Ship Pointing almost Vertically Upward 73

Falling to the Sea 73

Just Before the Air-Ship Lost all its Gas 74

Losing its Gas and Sinking 74

The Balloon Falling to the Waves 75

Boats Around the Ruined Air-Ship 75

Manoeuvring Above the Bay at Monte Carlo 77

Professor John Milne 80

_From a photograph by S. Suzuki, Kudanzaka, Tokio._

Professor Milne's Sensitive Pendulum, or Seismograph, as it Appears Enclosed in its Protecting Box 81

The Sensitive Pendulum, or Seismograph, as it Appears with the Protecting Box Removed 81

Gifu, Japan, after the Earthquake of 1891 85

_This and the pictures following on pages 89, 101, 111, are from Japanese photographs reproduced in "The Great Earthquake in Japan, 1891," by John Milne and W. K. Burton._

The Work of the Great Earthquake of 1891 in Neo Valley, Japan 89

Diagram Showing Vertical and Horizontal Sections of the More Sensitive of Professor Milne's Two Pendulums, or Seismographs 93

Seismogram of a Borneo Earthquake that Occurred September 20, 1897 94

Effect of the Great Earthquake of 1891 on the Nagara Gawa Railway Bridge, Japan 101

Pieces of a Submarine Cable Picked Up in the Gulf of Mexico in 1888 108

_The kinks are caused by seismic disturbances, and they show how much distortion a cable can suffer and still remain in good electrical condition, as this was found to be._

Record made on a Stationary Surface by the Vibrations of the Japanese Earthquake of July 19, 1891 111

_Showing the complicated character of the motion (common to most earthquakes), and also the course of a point at the centre of disturbance._

Table of Temperatures 115

Mr. E. G. Acheson, One of the Pioneers in the Investigation of High Temperatures 125

The Furnace-Room, where Carborundum is Made 131

"_A great, dingy brick building, open at the sides like a shed._"

Taking Off a Crust of the Furnace at Night 135

_The light is so intense that you cannot look at it without hurting the eyes._

The Interior of a Furnace as it Appears after the Carborundum has been Taken Out 143

Blowing Off 147

"_Not infrequently gas collects, forming a miniature mountain, with a crater at its summit, and blowing a magnificent fountain of flame, lava, and dense white vapour high into the air, and roaring all the while in a most terrifying manner._"

Side View of the Solar Motor 155

Front View of the Los Angeles Solar Motor 159

The Brilliant Steam Boiler Glistens in the Centre 163

The Rear Machinery for Operating the Reflector 167

Trees Growing in Water at Professor Nobbe's Laboratory 187

Experimenting with Nitrogen in Professor Nobbe's Laboratory 191

Mr. Charles S. Bradley 198

Mr. D. R. Lovejoy 199

Eight-Inch 10,000-Volt Arcs Burning the Air for Fixing Nitrogen 200

Machine for Burning the Air with Electric Arcs so as to Produce Nitrates 201

Marconi. The Sending of an Epoch-Making Message 206

_January 18, 1903, marks the beginning of a new era in telegraphic communication. On that day there was sent by Marconi himself from the wireless station at South Wellfleet, Cape Cod, Mass., to the station at Poldhu, Cornwall, England, a distance of 3,000 miles, the message--destined soon to be historic--from the President of the United States to the King of England._

Preparing to Fly the Kite which Supported the Receiving Wire 213

_Marconi on the extreme left._

Mr. Marconi and his Assistants in Newfoundland: Mr. Kemp on the Left, Mr. Paget on the Right 217

_They are sitting on a balloon basket, with one of the Baden-Powell kites in the background._

Marconi Transatlantic Station at Wellfleet, Cape Cod, Mass. 229

At Poole, England 231

Nearer View, South Foreland Station 235

Alum Bay Station, Isle of Wight 237

Marconi Room, S.S. Philadelphia 241

Transatlantic High Power, Marconi Station at Glace Bay, Nova Scotia 247

Work on the Smith Point Lighthouse Stopped by a Violent Storm 254

_Just after the cylinder had been set in place, and while the workmen were hurrying to stow sufficient ballast to secure it against a heavy sea, a storm forced the attending steamer to draw away. One of the barges was almost overturned, and a lifeboat was driven against the cylinder and crushed to pieces._

Robert Stevenson, Builder of the Famous Bell Rock Lighthouse, and Author of Important Inventions and Improvements in the System of Sea Lighting 256

_From a bust by Joseph, now in the library of Bell Rock Lighthouse._

The Bell Rock Lighthouse, on the Eastern Coast of Scotland 257

_From the painting by Turner. The Bell Rock Lighthouse was built by Robert Stevenson, grandfather of Robert Louis Stevenson, on the Inchcape Reef, in the North Sea, near Dundee, Scotland, in 1807-1810._

The Present Lighthouse on Minot's Ledge, near the Entrance of Massachusetts Bay, Fifteen Miles Southeast of Boston 260

"_Rising sheer out of the sea, like a huge stone cannon, mouth upward._"--Longfellow.

The Lighthouse on Stannard Rock, Lake Superior 261

_This is a stone-tower lighthouse, similar in construction to the one built with such difficulty on Spectacle Reef, Lake Huron._

The Fowey Rocks Lighthouse, Florida 264

Fourteen-Foot Bank Light Station, Delaware Bay, Del. 268

The Great Beds Light Station, Raritan Bay, N. J. 270

_A specimen of iron cylinder construction._

A Storm at the Tillamook Lighthouse, in the Pacific, one mile out from Tillamook Head, Oregon 275

Saving the Cylinder of the Lighthouse at Smith Point, Chesapeake Bay, from being Swamped in a High Sea 279

_When the builders were towing the unwieldy cylinder out to set it in position, the water became suddenly rough and began to fill it. Workmen, at the risk of their lives, boarded the cylinder, and by desperate labours succeeded in spreading sail canvas over it, and so saved a structure that had cost months of labour and thousands of dollars._

Great Waves Dashed Entirely Over Them, so that They had to Cling for Their Lives to the Air-Pipes 285

_In erecting the Smith Point lighthouse, after the cylinder was set up, it had to be forced down fifteen and a half feet into the sand. The lives of the men who did this, working in the caisson at the bottom of the sea, were absolutely in the hands of the men who managed the engine and the air-compressor at the surface; and twice these latter were entirely deluged by the sea, but still maintained steam and kept everything running as if no sea was playing over them._

Peter Cooper Hewitt 292

_With his interrupter._

Watching a Test of the Hewitt Converter 299

_Lord Kelvin in the centre._

The Hewitt Mercury Vapour Light 305

_The circular piece just above the switch button is one form of "boosting coil" which operates for a fraction of a second when the current is first turned on. The tube shown here is about an inch in diameter and several feet long. Various shapes may be used. Unless broken, the tubes never need renewal._

Testing a Hewitt Converter 311

_The row of incandescent lights is used, together with a voltmeter and ammeter, to measure strength of current, resistance, and loss in converting._

BOYS' SECOND BOOK OF INVENTIONS