‹‹‹ Vitr. 2.9.9 | Table of Contents | Vitr. 2.9.11 ›››
10The alder, which grows on the banks of rivers, and is to appearance an almost useless wood, possesses nevertheless most excellent qualities, inasmuch as it contains much air and fire, not a great deal of earth, and less water. Its freeness from water makes it almost eternal in marshy foundations used for piling under buildings, because, in these situations, it receives that moisture which it does not possess naturally. It bears immense weights and does not decay. Thus we see that timber which above ground soon decays, lasts an amazing time in a damp soil.
10The alder, which is produced close by river banks, and which seems to be altogether useless as building material, has really excellent qualities. It is composed of a very large proportion of air and fire, not much of the earthy, and only a little moisture. Hence, in swampy places, alder piles driven close together beneath the foundations of buildings take in the water which their own consistence lacks and remain imperishable forever, supporting structures of enormous weight and keeping them from decay. Thus a material which cannot last even a little while above ground, endures for a long time when covered with moisture.