Measuring height of tree.
To measure the space between two distant objects, D and E. Line A B on one, then move this right-angled triangle until F G is lined on the other, with B G in line with G H. B G equals the space between D and E then.
If the distance is considerable, it may be measured sometimes by sound. Thus, when a gun is fired, a man is chopping, or a dog barking, count the seconds between the sight and the hearing of the sound, and multiply by eleven hundred feet, which is the distance sound travels in a second.
To climb a tree that is too thick--Place small tree against it.
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Occasionally, the distance of an upright bank, cliff, or building can be measured by the echo. Half the seconds between shout and echo, multiplied by eleven hundred gives the distance in feet.
The usual way to estimate long distances is by the time they take to cover. Thus, a good canoe on dead water goes four to five miles an hour. A man afoot walks three and a half miles an hour on good roads. A packtrain goes two and a half miles an hour, or perhaps one and a half on the mountain trails.
A man's thumb is an inch wide.