5 , encyclopedia of united states supreme court reports ( p. 759 ) , it is said : although it has been held , that where a state has delegated the power of eminent domain to a person or corporation and where by its exercise lands have been subject to a public use , they can not be applied to another public use without specific authority expressed or implied to that effect , yet , the general rule seems to be that the fact that property is already devoted to a public use , does not exempt it from being appropriated under the right of eminent domain but it may be so taken for a use which is clearly superior or paramount to the one to which it is already devoted .