Column 1 gives the number of the spark or the number of seconds. Column 2 gives the corresponding number of sinuosities or vibrations. Column 3 gives the difference between the 1st and 7th ÷ 6, 2nd and 8th ÷ 6, etc. 1 0.3 255.83 2 256.1 255.90 3 511.7 255.90 4 767.9 255.93 5 1023.5 255.92 6 1289.2 256.01 7 1535.3 255.95 ------- 8 1791.5 255.920 = mean. 9 2047.1 - .028 = correction for rate. ------- 10 2303.5 255.892 11 2559.0 + .180 = correction for temperature. ------- 12 2825.3 256.072 = number of vibrations per second at 65° Fahr. 13 3071.0 In the following _résumé_, column 1 gives the number of the experiments. Column 2 gives the total number of seconds. Column 3 gives the result not corrected for temperature. Column 4 gives the temperature Fahrenheit. Column 5 gives the final result. Column 6 gives the difference between the greatest and least values: 1 13 255.892 80 256.072 0.18 2 11 255.934 81 256.126 0.17 3 13 255.899 81 256.091 0.12 4 13 255.988 75 256.108 0.13 5 11 255.948 75 256.068 0.05 6 12 255.970 75 256.090 0.05 7 12 255.992 75 256.112 0.20 8 11 255.992 76 256.124 0.03 9 11 255.888 81 256.080 0.13 10 13 255.878 81 256.070 0.13 ------- Mean = 256.094 Effect of Support and of Scraping. The standard Vt₃ fork held in its wooden support was compared with another fork on a resonator loaded with wax and making with standard about five beats per second. The standard was free from the cylinder. The beats were counted by coincidences with the ⅕ second beats of a watch. _Specimen._ Coincidences were marked-- At 32 seconds. 37 seconds. 43.5 seconds. 49 seconds. 54.5 seconds. 61.5 seconds. 61.5 - 32 = 29.5. 29.5 ÷ 5 = 5.9 = time of one interval. _Résumé._ 1 5.9 2 6.2 3 6.2 4 6.2 ---- Mean = 6.13 = time of one interval between coincidences. In this time the watch makes 6.13×5 = 30.65 beats, and the forks make 30.65 + 1 = 31.65 beats. Hence the number of beats per second is 31.65 ÷ 6.13 = 5.163. _Specimen._ Circumstances the same as in last case, except that standard Vt₃ fork was allowed to trace its record on the lampblacked paper, as in finding its rate of vibration. Coincidences were marked at-- 59 seconds. 04 seconds. 10.5 seconds. 17 seconds. 77 - 59 = 18. 18 ÷ 3 = 6.0 = time of one interval. _Résumé._