Page:Scott's Last Expedition, Volume 1.djvu/381

Rh and hope it will not make us slack; but it is good to see everyone in such excellent spirits—so far not a rift in the social arrangements.

Monday, April 24.—A night watchman has been instituted mainly for the purpose of observing the aurora, of which the displays have been feeble so far. The observer is to look round every hour or oftener if there is aught to be seen. He is allowed cocoa and sardines with bread and butter—the cocoa can be made over an acetylene Bunsen burner, part of Simpson's outfit. I took the first turn last night; the remainder of the afterguard follow in rotation. The long night hours give time to finish up a number of small tasks—the hut remains quite warm though the fires are out.

Simpson has been practising with balloons during our absence. This morning he sent one up for trial. The balloon is of silk and has a capacity of 1 cubic metre. It is filled with hydrogen gas, which is made in a special generator. The generation is a simple process. A vessel filled with water has an inverted vessel within it; a pipe is led to the balloon from the latter and a tube of india-rubber is attached which contains calcium hydrate. By tipping the tube the amount of calcium hydrate required can be poured into the generator. As the gas is made it passes into the balloon or is collected in the inner vessel, which acts as a bell jar if the stopcock to the balloon is closed.

The arrangements for utilising the balloon are very pretty.

An instrument weighing only 2¼ oz. and recording the