Thursday, April 24, 2014

Some times I wonder...

From The Book of Knowledge: The Children's Encyclopedia
In case you were wondering, if soldiers didn't break step while crossing a bridge, the vibration of the rhythmic step and swing of the arms might put too much stress on various parts of the bridge. 

The Book of Knowledge: The Children's Encyclopedia. E.V. McLoughlin, ed. The Grolier Society Inc., New York. 1954.
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1 comment:

Be nice. Nothing inappropriate, please.

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