But you can learn, said Webb.
I can try, replied Walter.
That is all that is required. You must try and be accurate. There is no such thing as good enough. Everything must be done accurate.
I will try my best, said Walter.
That is all that is required, and to-night I will give you the first lesson.
After supper, Webb and Walter went to the top of the hill. The compass was properly adjusted on the tri-pod.
Now, said Webb, I want you to level the instrument. That is very important. Unless the compass is exactly level, the needle will not balance.
Walter took hold of one of the sights and attempted to level the instrument, but failed.
Take hold of both of the sights, boy, one with your right and the other with your left hand. Use force enough to bring the bubbles in the centre of the glasses forward. Then do the same with the cross level.
I see, said Walter. This glass levels it one way and the other glass the other way, and when the bubbles are in the centre of both glasses, the compass is level. Let me try it again.