B. C. BATCHELLER, B.Sc.

MECHANICAL ENGINEER

PHILADELPHIA
PRESS OF J. B. LIPPINCOTT COMPANY
1897

[CONTENTS.]

CHAPTER I.
A BRIEF HISTORICAL SKETCH.	PAGE
Early Records	[9]
Practical beginning of the Art—The London PneumaticTelegraph	[10]
The Siemens Circuit System	[14]
Recent Improvements in the London System	[16]
An Underground Pneumatic Railway for Transportationof 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 FIRSTPNEUMATIC TUBES FOR THE TRANSPORTATIONOF 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 BATCHELLERPNEUMATIC TUBE COMPANY.
General Arrangement and Adaptability of theSystem	[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 TransferApparatus	[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 TOPNEUMATIC 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]