A little on hemp, a very useful product in construction, as almost anywhere else. Concerns not so much its use in construction, which the book does address briefly, but rather its qualities and ill reputation.
Hemp fibre is the strongest natural fibre known to man and is reputedly stronger, weight for weight, than steel. Hemp grows very fast, from nothing to 4m high in four months and is virtually disease resistant. It can be used in rotation with other crops and helps improve the soil. Hemp got a bad name in the 1930s after publicity campaigns by the petrochemical industry linking it to its narcotic derivative, cannabis, got it banned (in order to promote oil-based materials). Nowadays industrial hemp has virtually no narcotic content, but still needs to be grown under license.
