Index to Subjects
Reading edition
Types of Ancient and Modern Machines Page
General knowledge lacking5
Key-driven machine, first of the modern machines6
Recording, the primary feature of adding machines that print7
Validity and priority of invention8
Description of Pascal’s invention11
Constructional features of the Pascal machine12
Increased capacity of modern calculator13
Patent office a repository of ineffectual efforts14
The Early Key-Driven Art
First attempt to use depressable keys for adding was made in America17
Description of Parmelee machine18
Foreign digit adders18
Single-digit adders lack capacity19
Some early U. S. patents on single-digit adding machines20
Calculating machines in use abroad for centuries21
First key-driven machines no improvement to the Art21
Description of the Hill machine22
Hill machine at National Museum25
Inoperativeness of Hill machine25
High speed of key drive26
Camera slow compared with carry of the tens26
Hill machine merely adding mechanism, incomplete as operative machine29
Chapin and Stark patents29
Description of Chapin machine29
Inoperativeness of Chapin machine30
Description of Stark machine33
Inoperativeness of Stark machine37
Nine keys common to a plurality of orders37
Description of Robjohn machine38
First control for a carried numeral wheel41
Description of Bouchet machine42
Bouchet machine marketed43
Misuse of the term “Calculating Machine”43
Description of Spalding machine47
Prime actuation of a carried wheel impossible in the Spalding machine49
The Key-Driven Calculator
Theory versus the concrete50
All but one of the generic elements solved51
Originality of inventions51
A conception which led to the final solution52
Evolution of an invention55
Trials of an inventor55
The first “Comptometer”56
Felt patent 371,49656
Description of Felt calculator59
Recapitulation of Art prior to Felt calculator60
Why Hill failed to produce an operative machine61
Idiosyncrasies of force and motion increased by use of keys61
Light construction a feature62
Operative features necessary62
Classification of the features contained in the early Art of key-driven machines63
Carrying mechanism of Felt’s calculator63
Transfer devices64
Carrying mechanism versus mere transfer devices64
Details of Felt carrying mechanism65
Manufacture of the Felt calculator69
Trade name of Felt calculator70
Felt calculator exhibit at National Museum70
Significant proof of Felt’s claim of priority75
Rules for operation an important factor of modern calculator76
Early Efforts in the Recording Machine Art
First attempt to record arithmetical computation79
Description of Barbour machine80
Barbour machine not practical81
Description of Baldwin machine82
Baldwin’s printing mechanism89
First key-set crank-operated machine and first attempt to record the items in addition90
Description of Pottin machine91
Early efforts of Wm. S. Burroughs95
General scheme of Burroughs’ first inventions96
Brief description of machine of early Burroughs’ patents97
All early arithmetical printing devices impractical101
Practical method for recording disclosed later102
Inoperative features of early recording mechanism105
Adding mechanism attached to typewriter105
Description of Ludlum machine106
Ludlum machine inoperative108
First Practical Recorders
Burroughs a bank clerk111
Felt interested in recorder Art111
Felt’s first recording machine113
Felt recording mechanism combined with his calculating machine113
Description of Felt’s first recorder114
First individualized type impression combined with printing sector115
First practical arithmetical recorder116
The first sale of a recording adding machine on record116
Features of first practical recorder119
Description of Felt’s second recorder120
Felt principle of printing adopted by all manufacturers of recorders124
Wide paper carriage for tabulating124
The wide paper carriage machine127
Litigation on tabulator patents127
“Cross Tabulating”128
Felt recorder in “Engineering” of London, England131
Total recording a Felt combination131
Legible listing of items and automatic recording of totals first achieved by Felt132
The key-set principle more practical for recorders135
Description of first practical Burroughs recorder137
Date of use of first practical Burroughs recorder140
Introduction of the Modern Accounting Machine
Opposition to the use of machines for accounting144
Banks more liberal in recognition145
Improvement slow for first few years146
The High-Speed Calculator
Felt improvements on Comptometer149
Scientific distribution of functions150
Power consumed by old carrying method151
Cam and lever carrying mechanism152
One-point carrying cam impossible153
Felt’s improved method of carrying153
Gauging and controlling prime actuation154
Alternating stop scheme155
Multiplex key action156
Control of the carry by the next higher actuator156
Forced simultaneous key action old157
Forced simultaneity applied to a calculator impossible157
Flexible simultaneity of key action a Felt invention158
Duplex Comptometer159
Introduction of full-stroke mechanism159
Error signal keyboard160
Locking of the other orders by a short key-stroke161
Inactive keys locked during proper key-action in cash register161
Inactive keys not locked during proper key-action in “Comptometer”161
“Controlled-key Comptometer”162
The mass of recorder inventions patented163
But few of the recorder patents of value163
Reserve invention as good insurance164
Erroneous advertising164
Error key166
Sub-total166
Repeat key166
Locked keyboard166
Quick paper return166
Paper stop167
Cross tabulating167
Item stop167
Motor drive168
Distinguishing marks for clear, totals, and sub-totals168
Adding cut-out168
Self-correcting keyboard169
Split keyboard169
Dual action keyboard169
Non-add signal170
Selective split keyboard170
Selective printing cut-out171
Grand totalizer171
Alternate cross printing171
Determinate item signal172
Subtraction by reverse action172
Selective split for keyboard172
Rapid paper insert and ejector172
The Bookkeeping and Billing Machine
Early combinations174
First practical combination177
Moon-Hopkins Billing machine177
Napier’s Bones first direct multiplier181
First direct multiplying machine181
Description of Barbour Multiplier182
Description of Bollee machine188
Bollee’s principle commercialized189
A Closing Word
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