The most durable of fences are those formed of small oaks, split lengthwise by the wedge into thin boards.
It is not as durable as round rope and is heavier for the same working strength.
A more durable and more beautiful stone for building is the reddish or reddish-brown Potsdam sandstone of which there are extensive formations on the N.W.
The live oak is one of the most valuable timber trees of the genus, the wood being extremely durable, both exposed to air and under water; heavy and closegrained, it is perhaps the best of the American oaks for shipbuilding, and is invaluable for water-wheels and mill-work.
Masonry and concrete are more durable than metal, and metal than timber.