CHAPTER I

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A BRIEF HISTORICAL SKETCH. PAGE

EARLY RECORDS 9

PRACTICAL BEGINNING OF THE ART—THE LONDON PNEUMATIC TELEGRAPH 10

THE SIEMENS CIRCUIT SYSTEM 14

RECENT IMPROVEMENTS IN THE LONDON SYSTEM 16

AN UNDERGROUND PNEUMATIC RAILWAY FOR TRANSPORTATION OF MAIL 19

THE BERLIN PNEUMATIC TELEGRAPH 20

THE PARIS PNEUMATIC TELEGRAPH 22

THE PNEUMATIC TELEGRAPH OF OTHER CITIES 25

PNEUMATIC TUBES IN AMERICA 25

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