The Rallying Cry of Secession. The appeal to states' rights is of the most potent symbols of the American Civil War, but confusion abounds as to the historical and present meaning of this federalist principle. South Carolinians crowd into the streets of Charleston in 1860 to hear speeches promoting secession.
A dry riser is a main vertical pipe intended to distribute water to multiple levels of a building or structure as a component of the fire suppression systems. The pipe is maintained empty of water. The dry riser is the opposite of a wet riser or wet standpipe system where the pipes are kept full of water for manual or automatic fire fighting operations. Dry risers have to allow access to a fire engine within 18 m of the dry riser inlet box.
A dry dam also known as a flood retarding structure, is a dam designed to control flooding. It normally holds back no water and allows the channel to flow freely, except during periods of intense flow that would otherwise cause flooding downstream.urthermore, the designer tries to shape the dam so if one were to consider the part of dam above any particular height to be a whole dam itself, that dam also would be held in place by gravity. i.e. there is no tension in the upstream face of the dam holding the top of the dam down.