PAGE Foreword 1 Types of Ancient and Modern Machines 5 The Early Key-Driven Art 17 The Key-Driven Calculator 50 Early Efforts in the Recording Machine Art 79 First Practical Recorders 111 Introduction of the Modern Accounting Machine 144 The High-Speed Calculator 149 The Improved Recorder 163 The Bookkeeping and Billing Machine 174 A Closing Word 190 Illustrations 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