Fie ert a eon ae 
on the Elasticity of certain Metals 353 
were required for hot water to assume the temperature of the 
room, and it is not advisable to compare together observations 
made at long intervals, since the longer the interval the greater 
— becomes the danger that the conditions of the observation 
change in a manner to exercise on the period of vibration an in- 
fluence feeble indeed, yet perhaps sensible, in view of the slight 
extent of the variations under consideration. For the same rea- 
son there are objections to employing water at different tempe- 
ratures, since its renewal is scarcely possible without jarring the 
apparatus. 
2. Reduction of the observations.—In the calculation of the data 
obtained from observations made with gradually diminishing 
temperatures, certain corrections are necessary, hick render the 
reductions somewhat complicated. The manner in which the 
calculation was conducted, can be best — a means of 
the spider es oe the position of rest. These times of 
elongation are contained in the first column of Table I (See 
below). In the second column is contained the number of 
vibrations transpired between these times; in the third the 
period of vibration obtained by the division of the intervals in 
column one, by the numbers in column two. 
TABLE 1. 
‘ ee Temperature 
Times of Period of —_ ‘ 
elongation. sthenthoin. vibration. Observed. Corrections. Corrected. 
od ‘ sec. ° ° 
tei: AR Se cee eee, ee ee 
ll 1 8-60 9 20°9667 75-2 —2°95 72°25 
4 17-08 9 20°9422 71°38 —2°83 68°97 
12 38-68 24 20°9000 66-4 2°61 7 
22 43°50 29 20°8558 58°8 —2°28 56°52 
ay 24-12 25 20°8248 52°7 — 2°04 50°66 
1 44 54-73 39 20°7849 46°7 —1-78 
12 li 24°78 58 20°7352 364 —1°36 35°04 
49 9-78 92 20-7065 3i —115 30°05 
1 F 96 20°6861 27°0* 1-00 26" 
22 15°69 ara’ 24-98 
mometers, and then traced on codrdinate paper, with the tim 
of its observation as abscissa. The temperature for any nie 
ment can then be obtained from the curve, with an accuracy of 
about 0°-2 for the higher and about 0°1 for the lower bellyra tend 
The numbers in the 4th column are these mean temper- 
