Kalin-Burkhart Logical-Truth Calculator, 144-66, 248; cost, 165; reliability, 166; speed, 166 key punch, 47-8, 96, 235 keyboard, 48 knots, 17 language of logic, 56-62, 105, 140; _see also_ mathematical logic languages, 10-21, 231 latch relay, 40-1 left-hand components, 56, 121, 215 library, 9, 181 Library of Congress, 15 lie detector, 192 line of coding, 99 linear, 224-5 linear interpolation, 221 linear simultaneous equations, 141, 225 lobe, 94-5 logarithm, 67, 85, 106-8, 139, 225 Logarithm-In-Out counter, 107 logic, 144; _see also_ mathematical logic logical choice, 4; _see also_ mathematical logic logical connective, 148, 222 logical operations, 56-62, 173 logical pattern, 145-6 logical truth, 144-56, 166 Logical-Truth Calculator, 144-66; _see_ Kalin-Burkhart Logical-Truth Calculator loopholes, 149 Low Primary (output of sequencer), 61-2 Low Secondary (output of sequencer), 61-2 Lower Brushes, 52 loxodrome, 69-70 machine call number, 99 machine cycle, 56 machine language, 29, 99, 175, 191 machines as a language for thinking, 19-20; references, 231-2 machines involving voice and speech, 185-6, 254 magnetic surfaces, 17, 20, 168-70, 179 magnetic tape, 169-70, 179 magnetic wire, 168 magnetized spot, 168-70 main connective, 160 many-wire cable, 50 Mark I (Harvard IBM Automatic Sequence-Controlled Calculator), 10, 89-112, 245-6; _see also_ Harvard IBM Automatic Sequence-Controlled Calculator Mark II (Harvard Sequence-Controlled Relay Calculator), 176-8, 249 Mark III (Harvard Sequence-Controlled Electronic Calculator), 177 Massachusetts Institute of Technology, 1, 20, 65, 72-88, 153 Massachusetts Institute of Technology’s Differential Analyzer No. 2, 65-88; accuracy, 86; cost, 87; reliability, 87; speed, 87 master card, 50 Master Programmer, 115-6 matching, 173 mathematical biophysics, 230 mathematical logic, 26, 36, 56-62, 105, 140, 151-2, 164, 221-3, 248 matrices, 173, 227 matrix, 173, 227 meanings, 209, 231 measurements, 65-6, 68 mechanical brain, 1, 5-8, 20; crucial devices for, 20 mechanical brains under construction, 176-9 memory, 27, 90-1 mentality, 24, 27 mercury tank, 171, 179 merging, 173 metal fingers, 135 mica, 172 microphone, 185 mimeograph stencil, 16 Minoan, 188 miscellaneous field, 99 mistake, 134 Moore School of Electrical Engineering, 7, 113-27, 177, 249 multiplicand, 223 multiplicand counter, 101 multiplication schemes, 214-6 multiplier, 115-6 multiplier counter, 101 multiply-divide unit, 103 multiplying, 55-6, 101, 121, 140 multiplying punch, 47, 52, 235