while many courts have used sweeping expression in the decisions in which they have disclaimed the power of supervising the power of supervising the selection of the sites of public improvements , it may be safely said that the courts of the various states would feel bound to interfere to prevent an abuse of the discretion delegated by the legislature , by an attempted appropriation of land in utter disregard of the possible necessity of its use , or when the alleged purpose was a cloak to some sinister scheme . ''