1116 
TABLE 1. T.ABLBWIL 
Dilatometer 1. Dilatometer 2. 
ft | | 
t Vv t Vv t Vv t | u 
| | 
le} fe) fe} © 
0 1.15665 | 59.8 1.19170 0 1.15692 | 59.8 1.19348 
17.3 | 1.16148 || 59.8 1.19457 17.35 | 1.16168 || 50.8 1.19693 
40.5 | 1.16823 | 60 1.19643 40.7 1.16843 60 1.19877 
| 
tot 49.9 | 1.17125 || 60.1 | 1.19949 
50.1 | 1.17108 || 60.1 1.19719 | 
| 50.2 | 1.17137 || 60 1. 19976 
50.2 | 1.17110 || 60 1.19734 | 
| 50.1 | 1.17134 || 59.7 1.19918 
19.6 | 1.16238 | 59.7 | 1.19593 
18.2 | 1.16211 || 59.6 1.19575 
31.2 | 1.16542 || 59.6 | 1.19353 | | 
| 31.3 | 1.16587 | 64.6 1.20495 
41.1 | 1.16829 || 64.6 | 1.20480 (liquid) 
| (liquid) | 
| | 41.1 | 1.16863 || 54.25 | 1.17611 
49.7 | 1.17097 || 54.25 | 1.17452 | | (solid) 
| (solid) | 
49.7 | 1.17129 
55.1 | 1.17607 
| 55. | 1.17712 || 
58.2 | 1.18611 || 
| 58.2 | 1.18755 
19.7 | 1.16199 
| 19,7 | 1.16223 
0) ibe 15650 | | 
| 0 1.15680 || 
52.0) 1 ATT | | 
| 5-7. | 1.07841 
52.8 | 1.17258 | | 
| 52.8 | 1.17312 || 
52.85 | 1.17259 | | 
| 52.85 | 1.17317 
4. In order to calculate the coefficients of expansion, HAGEN 
only used the observations between O° and 50° C. He found that 
the coefficient increases rapidly above 50° C.; there is between this 
temperature and the melting point an increase of volume of 0.5 per 
cent which is followed by a sudden increase of 2.5 per cent at 
the melting point (62°,1). 
5. In order to get a clear survey of the phenomena the results 
of those determinations which ,were carried out with both dilato- 
meters at the same temperatures are summarized in Table III. The 
fourth column contains the differences of volume (in hundredths of 
amm*) of 1 gram of potassium which is found with the two 
instruments at the same temperature. 
