, 80 cm. long, and a cupric chloride cell
, and, secondly, by immersing the whole vessel
in a constant temperature bath
of gas-engine oil (40 liters), which permitted, in general, fluctuations of not more than .02° C. during an observation. This constant-temperature bath was found essential if such consistency of measurement as is shown here was to be obtained. A long search for causes of slight irregularity revealed nothing so important as this, and after the bath was installed all of the irregularities vanished. The atomizer
was blown by means of a puff of carefully dried and dust-free air introduced through cock
