The London, Edinburgh and Dublin philosophical magazine and journal of science . tself. The depres-sion due to the suspended weight as well as to its own weightin an unmagnetized bar is given by the approximate formula* where /, a, b are the length, breadth, and thickness of thebar, T and W the suspended weight and the weight of the baritself respectively, d and W refer to the part of the barlying between two fulcrums. The obseryed change of de-pression diyided by this depression is the ratio in question, that is, SEE Some of the results of our calculation are given in the following table. In
The London, Edinburgh and Dublin philosophical magazine and journal of science . tself. The depres-sion due to the suspended weight as well as to its own weightin an unmagnetized bar is given by the approximate formula* where /, a, b are the length, breadth, and thickness of thebar, T and W the suspended weight and the weight of the baritself respectively, d and W refer to the part of the barlying between two fulcrums. The obseryed change of de-pression diyided by this depression is the ratio in question, that is, SEE Some of the results of our calculation are given in the following table. In the calculation the effect ofthe weak spring stretching the thin copper wire wascorrected for. 1 H/T+fW. 329 gr. 829 gr. 1349 gr. 1849 gr. 5869 gr. 20 164xl0-2 0-77 Xl0~2 0-50 X10~2 0-47X10-2 0-44X10-2 30 2-79 1-47 1-09 1-08 0-88 50 315 1-84 1-35 1-28 1-16 100 3-36 1-92 1-48 137 1-28 250 3-40 1-93 1-51 1-40 1-32 400 340 1-93 1-51 1-40 1-32 These numbers show that the value of -^ becomes greater as the field is increased, and that it becomes less as the weightis increased. Fii. 5. Steel.—The general character of the change of depressionis similar to that of soft iron, as given in fig. 5 ; but the * Clebschs Elasticitcit, p. 37-5; Winkelmanns Physik, i. p. 266. 466 K. Honda, S. Shimizu, and S. Kusakabe on Change of initial decrease is not observed. Some of the values of -^are given in the following table : — h/t-kw . 1251 gr. 2184 gr. 3096 gr. 50 0-14 Xl02 0-15 X10 ~2 0-17 xl0~2 100 0-22 0-25 025 200 027 0-33 031 300 0-28 037 035 400 030 0-40 039 This steel bar shows a comparatively small increase of elasticity. With the present specimen, the value of -„- under a given field reaches a maximum with a load lyingbetween 1270 and 2200 grams. 6. Wolfram Steel.—The change of depression for Wolframsteel bar by magnetization is similar to that for soft iron, asshown in fig. 6. It is still greater, and the curve does not Fiar. 6. 918 7/
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Keywords: ., bookcentury1800, bookdecade1840, booksubjectscience, bookyear1840
