CHAPTER I.
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