From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Conversion table of speed (km/h or mph) to distance travelled per 1/2 second (metres or feet).
| Identifier | ExFiles\Box 113\2\ scan0174 | |
| Date | 11th November 1930 guessed | |
| DISTANCE TRAVERSED IN RELATION TO VARIOUS SPEEDS Speed Distance per 1/2 second Speed Distance per 1/2 second Speed Distance per 1/2 second Speed Distance per 1/2 second kms. or kms. or kms. or kms. or miles per METRES FEET miles per METRES FEET miles per METRES FEET miles per METRES FEET hour hour hour hour 1 0.14 .733 51 7.08 37.40 101 14.03 74.06 151 20.97 110.73 2 0.28 1.47 52 7.22 38.13 102 14.17 74.80 152 21.11 111.46 3 0.42 2.20 53 7.36 38.86 103 14.30 75.53 153 21.24 112.20 4 0.55 2.93 54 7.50 39.60 104 14.45 76.26 154 21.38 112.93 5 0.69 3.67 55 7.63 40.33 105 14.58 77.00 155 21.52 113.66 6 0.83 4.40 56 7.77 41.06 106 14.72 77.73 156 21.66 114.40 7 0.97 5.13 57 7.91 41.80 107 14.86 78.46 157 21.80 115.13 8 1.11 5.87 58 8.05 42.53 108 15.00 79.20 158 21.94 115.86 9 1.25 6.60 59 8.19 43.26 109 15.14 79.93 159 22.08 116.60 10 1.39 7.33 60 8.35 44.00 110 15.28 80.66 160 22.22 117.33 11 1.53 8.07 61 8.47 44.73 111 15.41 81.40 161 22.36 118.06 12 1.67 8.80 62 8.60 45.46 112 15.55 82.13 162 22.50 118.80 13 1.80 9.53 63 8.74 46.20 113 15.69 82.86 163 22.63 119.53 14 1.94 10.26 64 8.88 46.93 114 15.83 83.60 164 22.77 120.26 15 2.08 11.00 65 9.02 47.66 115 15.97 84.33 165 22.91 121.00 16 2.22 11.73 66 9.16 48.40 116 16.11 85.06 166 23.05 121.73 17 2.36 12.46 67 9.30 49.13 117 16.25 85.80 167 23.19 122.46 18 2.50 13.20 68 9.44 49.86 118 16.39 86.53 168 23.33 123.20 19 2.64 13.93 69 9.58 50.60 119 16.53 87.26 169 23.47 123.93 20 2.78 14.66 70 9.72 51.33 120 16.66 88.00 170 23.60 124.66 21 2.91 15.40 71 9.85 52.06 121 16.80 88.73 171 23.74 125.40 22 3.05 16.13 72 10.00 52.80 122 16.95 89.46 172 23.88 126.13 23 3.19 16.86 73 10.13 53.53 123 17.08 90.20 173 24.02 126.86 24 3.33 17.60 74 10.27 54.26 124 17.22 90.93 174 24.16 127.60 25 3.47 18.33 75 10.41 55.00 125 17.36 91.66 175 24.30 128.33 26 3.60 19.06 76 10.55 55.73 126 17.50 92.40 176 24.44 129.06 27 3.75 19.80 77 10.69 56.46 127 17.64 93.13 177 24.58 129.80 28 3.89 20.53 78 10.83 57.20 128 17.77 93.86 178 24.71 130.53 29 4.03 21.26 79 10.96 57.93 129 17.91 94.60 179 24.85 131.26 30 4.16 22.00 80 11.10 58.66 130 18.05 95.33 180 25.00 132.00 31 4.30 22.73 81 11.25 59.40 131 18.19 96.06 32 4.44 23.46 82 11.39 60.13 132 18.33 96.80 33 4.58 24.20 83 11.52 60.86 133 18.47 97.53 34 4.72 24.93 84 11.66 61.60 134 18.61 98.26 35 4.86 25.66 85 11.80 62.33 135 18.75 99.00 36 5.00 26.40 86 11.94 63.06 136 18.89 99.73 37 5.14 27.13 87 12.08 63.80 137 19.02 100.46 38 5.27 27.86 88 12.21 64.53 138 19.16 101.20 39 5.41 28.60 89 12.35 65.26 139 19.30 101.93 40 5.55 29.33 90 12.50 66.00 140 19.45 102.66 41 5.69 30.06 91 12.63 66.73 141 19.58 103.40 42 5.83 30.80 92 12.77 67.46 142 19.72 104.13 43 5.97 31.53 93 12.90 68.20 143 19.86 104.86 44 6.10 32.26 94 13.05 68.93 144 20.00 105.60 45 6.25 33.00 95 13.19 69.66 145 20.13 106.33 46 6.38 33.73 96 13.32 70.40 146 20.27 107.06 47 6.52 34.46 97 13.46 71.13 147 20.41 107.80 48 6.66 35.20 98 13.60 71.86 148 20.55 108.53 49 6.80 35.93 99 13.74 72.60 149 20.69 109.26 50 6.94 36.66 100 13.89 73.33 150 20.83 110.00 | ||