A、Big waves pose a threat to commercial navigation. B、The river current never flows faster ten miles per hour. C、The river rever

Today, I would like to begin by discussing early European settlement along one of our well-known rivers, the Hudson, which empties into the Atlantic to form New York bay. The Hudson river has a couple of interesting physical features that made it very attractive for settlement by the Europeans. The first is that river extends inland from the Atlantic Ocean for more than 150 miles with no waterfalls or rapids. Its surface is virtually flat for that entire distance, with no obstacles. Second, the whole 150-mile stretch is influenced by tides from the Atlantic Ocean. Roughly every six hours, the river reverses direction, flowing north when the tide is rising and south toward the ocean when the tide is going down. Obviously there were no obstacles to prevent settlers from moving further upstream on the Hudson river and this explains why the Dutch penetrated so far inland. They were the first Europeans to settle in the Hudson valley. Of course, to go upstream, the Dutch settlers needed the right kind of boat, and so to navigate the river, they design a sloop with only one mast but two sails, one rigged in front of the mast and one behind. The mast was very tall, in many cases over 100 feet tall, so that the large sails could catch winds blowing above the shore line hills. Hudson river sloops carried passengers and cargo. The cargo ranging from coal, lumber and hay to fruit, vegetables and livestock. Traveling only ten miles an hour in a good wind, the sloop was not too speedy by modern standards, but it was ideally suited to the Dutch settlement, and in fact when the steam boat eventually was introduced, it couldn’t keep up with the sloop.