Notes on Arctic Air. 41 
tween —73° and —57° (F), the blue paper had become distinctly 
pink along its edges. 
An attempt was made as follows to estimate this watery 
vapour. 
An india-rubber tube, with a mouth-piece holding a little cotton 
wool to catch ice crystals, was led from an elevation of ten feet 
over the floes through a ventilator into my cabin, and there con- 
nected with an aspirator with the intervention of two U tubes 
filled with fresh burnt calcium chloride. By this means 118°2 
litres of air were dried. The operation lasted nine hours, and at 
the end of the time the U tubes had increased only ‘053 gramme 
in weight. During the experiment the temperature of the exter- 
nal air was—54°'4 and the pressure 29°75. 
