Chapter I: Front Matter

Transcriber’s Notes:

The spelling, punctuation and hyphenation are as the original, with the exception of apparent typographical errors which have been corrected.

Italic text is denoted _thus_.

Bold text is denoted =thus=.

THE

PNEUMATIC DESPATCH TUBE SYSTEM

OF THE

BATCHELLER PNEUMATIC TUBE CO.

ALSO

FACTS AND GENERAL INFORMATION RELATING TO PNEUMATIC DESPATCH TUBES

BY B. C. BATCHELLER, B.Sc. MECHANICAL ENGINEER

PHILADELPHIA PRESS OF J. B. LIPPINCOTT COMPANY 1897

COPYRIGHT, 1896,

BY

B. C. BATCHELLER.

CONTENTS.

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

CHAPTER II.

THE PNEUMATIC TRANSIT COMPANY AND THE FIRST PNEUMATIC TUBES FOR THE TRANSPORTATION OF UNITED STATES MAIL.

ORGANIZATION 28

AIM AND OBJECT OF THE COMPANY 28

THE CLAY-LIEB PATENTS 30

FRANCHISES AND FIRST GOVERNMENT CONTRACT 33

SEARCH FOR TUBES 34

METHOD OF MANUFACTURING TUBES 35

LAYING AND OPENING THE TUBES FOR TRAFFIC 37

DESCRIPTION OF THE TUBES, METHOD OF LAYING, ETC. 38

THE AIR-COMPRESSOR—METHOD OF CIRCULATING THE AIR 40

TERMINAL APPARATUS 42

THE SENDER 43

SUB-POST-OFFICE RECEIVER 44

MAIN POST-OFFICE RECEIVER 47

THE CARRIER 50

OPERATION OF THE TUBES 52

BENEFITS OF THE SYSTEM 54

CHAPTER III.

THE SYSTEM AND APPARATUS OF THE BATCHELLER PNEUMATIC TUBE COMPANY.

GENERAL ARRANGEMENT AND ADAPTABILITY OF THE SYSTEM 57

THE SIZE OF TUBES 64

SYSTEM OF VERY LARGE TUBES 65

GENERAL ARRANGEMENT OF APPARATUS IN THE STATIONS—TWO-STATION, TWO-COMPRESSOR LINE 69

TWO-STATION, ONE-COMPRESSOR LINE 72

THREE- TO EIGHT-STATION LINE 74

SENDING APPARATUS 79

SENDING TIME-LOCK 84

INTERMEDIATE STATION TIME-LOCK 88

ELECTRO-PNEUMATIC CIRCUIT-CLOSER 91

THE OPEN RECEIVER 94

THE CLOSED RECEIVER 99

THE INTERMEDIATE STATION RECEIVING AND TRANSFER APPARATUS 106

CARRIERS 115

AIR SUPPLY 117

FANS 117

BLOWERS 117

AIR COMPRESSORS 118

THE TUBE, LINE CONSTRUCTION, ETC. 122

CHAPTER IV.

FACTS AND GENERAL INFORMATION RELATING TO PNEUMATIC TUBES.

DEFINITIONS 124

INTERMITTENT AND CONSTANT AIR-CURRENT 125

LAWS GOVERNING THE FLOW OF AIR IN LONG TUBES 126

LAW OF PRESSURE 128

USES OF PRESSURE CURVES 130

LAW OF VELOCITY 130

CHARACTERISTICS OF THE VELOCITY CURVE 132

USES OF VELOCITY CURVES 133

QUANTITY OF AIR USED 134

TEMPERATURE OF THE AIR 135

HORSE-POWER 136

EFFICIENCY 137

PRESSURE AND EXHAUST SYSTEMS 138

LAWS EXPRESSED IN MATHEMATICAL FORMULÆ 141

MOISTURE IN THE TUBES 142

LOCATION OF OBSTRUCTIONS IN TUBES 143