Growth in the building of canals was made possible by

The answer is: Improvements in engineering methods.

In order to build a canal, advanced engineering methods are needed to creates dams and locks so we can  stretches the slack water levels of the canals. This would be impossible with traditional engineering method.

Beside that, advanced engineering methods also reduce the time needed for the projects and reduce the cost of building the canals.

as university of miami psychologists debra lieberman and adam smith pointed out in a recent article in the journal current directions in psychological science, humans have social and psychological mechanisms to deter incest. with very few exceptions, marriages between brothers and sisters and between parents and their children are verboten in every human culture. the primary psychological anti-incest mechanism is the yuck response. even the idea of sex with their mom or dad, bro or sis is upsetting to most people. the psychologist jonathan haidt has found that nearly everyone is repelled by the prospect of brother-sister sex, even in hypothetical situations in which there is no chance of pregnancy).

the biological cost of incest

this raises an interesting question: just what’s so bad about incest? sure, having sex with your dad or your sister seems gross — but why? some anthropologists have argued that incest taboos are learned social conventions. this explanation, however, doesn’t make sense to me as it does not explain the widespread existence of anti-incest mechanisms in creatures ranging from cockroaches to chimpanzees. second, the incest taboo is about as close to a universal law as human moral rules get.

why should mechanisms to avoid incest be so widespread both in nature and across human societies? the answer is simple. the problem with having sex close with relatives is that there is an astonishingly high chance that your offspring will be born with a serious birth defect.

apart from being against desegregation, governor of georgia eugene talmadge opposed as well to the work progress administration, an ambitious program of the "new deal" created by president franklin d. roosevelt to overcome the great depression after world war i. talmadge disagreed with welfare spending, job training and organized labor. according to his ideas, he thought the government was spending too much money on this, and he wasn't willing to accept a wage higher than georgia's lower average wage. besides, talmadge strongly opposed to the "new deal" as he thought it had communist ideas.