( 39 ) 
Distance of | Menisc. level | Distance of |Approximate?) | Approximate 
| 3 
| : Mark. the meniscus | vol. between 
E the marks. sli mark, ovale | the levels, | mean bore. 
a 0.5 | 0.155 | | 
b 1.8 1.297 0.101 1.243 0.626 0.504 
c 8.7 1.885 0.103 1.887 0.958 0.507 
d 6.2 2.511 0.109 2.517 1.272 0.506 
e | —2.8 0.200 
mr 0.9 3.671 0.154 3.625 1.841 0.508 
9 13.0 12.020 0.138 12.004 6.035 0.503 | 
Hek 19.2 6.216 0.141 6.219 3.132 0.502 | 
i 29.1 9.823 0 207 9.889 4.997 0.505 
34.6 5.446 0.115 5.354 2.691 0.503 
k | 42.1 7.380 0.151 7.416 8.770 0.508 
Z| 48.8 6.600 0.127 6.576 3.352 0.510 
m | 52.3 3.467 0.187 3.527 1.791 0.508 
n (1,6) 
the volume of the tube as far as the level of the meniscus and 
derive from this a more accurate mean bore, which can serve for 
the volume between the meniscus level and the mark near it. 
Now we can determine the exact volume of the tube after it is 
sealed off, from the point of the capillary. For this we give the 
volume up to a given place at the beginning of the capillary ; these 
numbers have a constant value; in order to derive from them the 
total volume, we must each time add the volume of the closing 
capillary, which becomes smaller by being opened and sealed again 
when it is necessary to clean and fill with another gas. 
This capillary is too short and too narrow to be calibrated in 
the way described. The cock-piece was placed in a large basin filled 
with water, so that only the fine capillary projected beyond it and 
after long stirring the temperature and the height of the mercury 
were read. Then the temperature was raised a few degrees and the 
same thing was repeated. These are the results for the tube / A men- 
tioned above, at two different measurements, for which different 
cock-pieces were used. 
1) This column gives the differences of the column /volume of corresp.glass at 20° C,” 
