Late in life , gatling did divert his attention to steam-powered ploughs .
加特林到了晚年,他确实将注意力转移到了蒸汽式的犁。
Historically , women were much more involved in farming among groups that did not use ploughs .
历史上,女人在种群中更多地参加到没有使用犁的农业中。
Broadly speaking , ploughs are most useful for crops that require large tracts of land to be tilled in a short span of time , perhaps because the climate favours a grain with a relatively short growing season .