sentence1: You can also view a Roman Nileometer carved in the rock which measured the height of the river and helped the ancient priests to time the announcement of the Nile flood that initiated a movement of workers from the fields to community projects such as temple building.
sentence2: You can also view a Roman Nileometer carved in the rock which measured the height of the river and helped the ancient priests to time the announcement of the Nile ebbtide that initiated a movement of workers from the fields to community projects such as temple building.