Tidal range Tidal range Tidal range is the height difference between high tide and low tide. Tides are the rise and fall of sea levels caused by gravitational forces exerted by the Moon and Sun and the rotation of Earth. Tidal range is not constant but changes depending on the locations of the Moon and Sun. The most extreme tidal range occurs during spring tides, when the gravitational forces of both the Moon and Sun are aligned (syzygy), reinforcing each other in the same direction (new moon) or in opposite directions (full moon). During neap tides, when the Moon and Sun's gravitational
Monuments relating to the Haymarket affair rally at Haymarket and free speech. The planned site was to include an international commemoration wall, sidewalk plaques, a cultural pylon, a seating area, and banners, but construction has not yet begun. Monuments relating to the Haymarket affair There are several monuments to commemorate the Haymarket affair. In 1889, a commemorative nine-foot (2.7 meter) bronze statue of a Chicago policeman by sculptor Johannes Gelert was erected in the middle of Haymarket Square with private funds raised by the Union League Club of Chicago. The statue was unveiled on May 30, 1889, by Frank Degan, the son of Officer Mathias Degan.