Minute
Loss, Lengthen by Millimeters. Gain, Shorten by Millimeters. Number of Oscillations per Hour. Length in Meters. To Produce in 24 Hours 1 Minute. Loss Lengthen by Meters. Gain, Shorten by Meters. 3,600 0.9939 1.38 1.32 1,900 3.568 0.0050 0.0048 3,550 1.0221 1.42 1.36 1,800 3.975 0.0055 0.0053 3,500 1.0515 1.46 1.40 1,700 4.457 0.0062 0.0059 3,450 1.0822 1.50 1.44 1,600 5.031 0.0070 0.0067 3,400 1.1143 1.55 1.48 1,500 5.725 0.0080 0.0076 3,350 1.1477 1.60 1.53 1,400 6.572 0.0091 0.0087 3,300 1.1828 1.64 1.57 1,300 7.622 0.0106 0.0101 3,250 1.2194 1.69 1.62 1,200 8.945 0.0124 0.0119 3,200 1.2578 1.75 1.67 1,100 10.645 0.0148 0.0142 3,150 1.2981 1.80 1.73 1,000 12.880 0.0179 0.0171 3,100 1.3403 1.86 1.78 900 15.902 0.0221 0.0211 3,050 1.3846 1.93 1.84 800 20.126 0.0280 0.0268 3,000 1.4312 1.99 1.90 700 26.287 0.0365 0.0350 2,900 1.5316 2.13 2.04 600 35.779 0.0497 0.0476 2,800 1.6429 2.28 2.18 500 51.521 0.0716 0.0685 2,700 1.7669 2.46 2.35 400 80.502 0.1119 0.1071 2,600 1.9054 2.65 2.53 300 143.115 0.1989 0.1903 2,500 2.0609 2.87 2.74 200 322.008 0.4476 0.4282 2,400 2.2362 3.11 2.97 100 1,288.034 1.7904 1.7131 2,300 2.4349 3.38 3.24 60 3,577.871 4.9732 4.7586 2,200 2.6612 3.70 3.54 50 5,152.135 7.1613 6.8521 2,100 2.9207 4.06 3.88 1 12,880,337.930 17,903.6700 17,130.8500 2,000 3.2201 4.48 4.28 The numbers given represent the oscillations in an hour of mean time of a simple pendulum, measuring from the point of suspension to the center of a heavy spherical bob attached to a fine thread, and oscillating through an exceedingly small arc in a vacuum.
The compound or material pendulum employed for regulating horological trains will give the number of oscillations indicated in the table when the length set opposite that number is equal to the distance between the centers of suspension and oscillation.
The assumption that the center of oscillation coincides approximately with the point at which the pendulum will rest horizontally on a knife-edge, is only legitimate when the rod is very light, and the weight of the pendulum acts nearly through the center of the bob.
The watchmaker will do well to employ a small platinum ball, suspended in front of a carefully graduated vertical rule, by a fine thread that can be lengthened or shortened at will. If the point of suspension is determined by a clamp that is opened or closed by a set screw, it will be easy to adjust this pendulum to the length indicated in the table, and, by making it oscillate side by side with the compound pendulum under consideration, to ascertain the approximate position of the center of suspension of this latter. The length of the pendulum giving 1 oscillation in an hour (12,880,337.93 meters, or 507,109,080 inches), affords a useful datum for certain calculations with reference to the lengths of pendulums. For an oscillation of 2 deg. the lower end will travel through a space of 280 miles. In the above table all dimensions are given in meters and millimeters. If it is desirable to express them in feet and inches, the necessary conversion can be at once effected in any given case by employing the following conversion table, which will prove of considerable value to the watchmaker for various purposes.
Inches expressed in Millimeters and French Lines. Inches. Equal to Millimeters