The Roman History · Amm. 15.10.5

But in winter, the ground being covered over with a smooth crust of ice, and therefore slippery under foot, the traveller is often plunged headlong; and the valleys, which seem to open here and there into wide plains, which are merely a covering of treacherous ice, sometimes swallow up those who try to pass over them. On account of which danger those who are acquainted with the country fix projecting wooden piles over the safest spots, in order that a series of them may conduct the traveller unhurt to his destination; though if these piles get covered with snow and hidden, or thrown down by melting torrents descending from the mountains, then it is difficult for any one to pass, even if natives of the district lead the way.

Ammianus Marcellinus · translated by C. D. Yonge · 1911 reprint
C. D. Yonge translation (preface dated February 1862); G. Bell and Sons, 1911; Project Gutenberg #28587
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