We had aneroid barometers for work away from the river and these were constantly compared with and adjusted to the mercurials.

The tubes of mercury sometimes got broken, and then a new one had to be boiled to replace it.

I believe the boiling of tubes has since that time been abandoned, as there is not enough air in the tube to interfere with the action of the mercury, but at that time it was deemed necessary for accuracy, and it gave Prof.endless trouble.

The wind was always blowing, and no tent we could contrive from blankets, and waggon sheets (we had no regular tents), sufficed to keep the flame of the alcohol lamp from flickering.

Nevertheless, Prof.whose patience and dexterity were unlimited, always succeeded.