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PAGE |
| Frontispiece, “Stone Age Calculating” |
|
| One of the Pascal Machines |
10 |
| Photo of Blaise Pascal |
11 |
| Parmelee Patent Drawings |
16 |
| Hill Patent Drawings |
23 |
| Chapin Patent Drawings |
28 |
| From the Stark Patent Drawings |
32 |
| From the Robjohn Patent Drawings |
36 |
| From Drawings of Bouchet Patent 314,561 |
40 |
| Drawings of Spalding Patent No. 293,809 |
46 |
| “Macaroni Box” Model |
53 |
| Photo of Dorr E. Felt |
55 |
| The First “Comptometer” |
57 |
| From Drawings of Felt Patent No. 371,496 |
58 |
| Bill for First Manufacturing Tools of the Comptometer |
68 |
| Early Comptometer |
69 |
| Letter from Geo. W. Martin |
71 |
| Testimonial |
72 |
| Testimonial |
73 |
| Letters from Elliott and Rosecrans |
74 |
| From Drawings of Barbour Patent No. 133,188 |
78 |
| From Drawings of Baldwin Patent No. 159,244 |
83 |
| Baldwin Machine |
83 |
| From Drawings of Pottin Patent No. 312,014 |
88 |
| From Drawings of Burroughs Patent No. 388,118 |
94 |
| Photo of Wm. S. Burroughs |
95 |
| Drawings of Ludlum Patent No. 384,373 |
104 |
| From Drawings of Felt Patent No. 405,024 |
112 |
| Testimonial |
117 |
| Felt Recording and Listing Machine |
118 |
| From Drawings of Felt Patent No. 465,255 |
121 |
| Felt Tabulator |
126 |
| One of the Early “Comptographs” |
130 |
| Photo of Gottfried Wilhelm Leibnitz |
132 |
| Leibnitz Calculator |
133 |
| From Drawings of Burroughs’ Patents Nos. 504,963 and 505,078 |
136 |
| Burroughs’ Recorder |
137 |
| From the February 1908 Issue of Office Appliances Magazine |
142 |
| The High-Speed Calculator |
148 |
| Two Pages from Wales Adding Machine Co. Booklet |
165 |
| Moon-Hopkins Billing and Bookkeeping Machine |
176 |
| Napier’s Bones |
179 |
| From Drawings of Barbour Patent No. 130,404 |
180 |
| Photo of John Napier |
181 |
| From Drawings of Bollee Patent No. 556,720 |
186 |