1087 
as we think, mutually comparable observations. The logarithmic 
decrements 0 as observed are given in. the following table, which 
also contains the mean times at which the observations took place 
(they lasted about 4 minutes; each time 20 full oscillations were 
observed '), as well as the physical state of the substance which 
“surrounded the sphere. 
de 11°25" a.m. vapour 0 = 0:00393 
2. A OEE a 379 
3. 15 50" En, 4 370 
4. AAE ANS: liquid 682 
5. HADI se 672 
6. PAA hie M 663 
fit 215 p.m. vapour 340 
8. DBDs es JA 317 
2 DAO, és 317 
We shall now give a short deseription of the course of the 
observations. After the apparatus had been filled with hydrogen — 
gas for a few days, we began to cool it in the morning of July 
12" at about 10 a.m. and about 11 a.m. liquid was poured in, 
only so far that the sphere did not yet touch the liquid, when 
three observations were taken in the vapour; it appears that the 
decrement decreased rapidly, which seems to indicate a disturbance 
in the wire caused by the filling of the apparatus. About 12 o’cl. 
more liquid was poured in until the sphere was entirely immersed ; 
again three observations were made, which gave a much larger 
decrement, and this in the same way decreased in the course of 
time, and to about the same degree as in the vapour. About 1 p.m. 
the external vacuum glass was removed, so that the liquid 
hydrogen could boil away pretty quickly; at about 2 p.m. the 
liquid had so far boiled away that the sphere projected completely 
out of the liquid; then the vacuum glass with liquid air was again 
put round the internal one, and three more observations were made 
in the vapour. 
From our observations it follows, that the transference of the 
sphere from the vapour into the liquid involves an increase of the 
logarithmic decrement by a mean value of 0:00319, while for the 
1) As we did not expect a greater accuracy than 1 °/, about, we considered it 
useless to raise the degree of accuracy for the separate results by lengthening 
the series. 
69* 
