The application is wholly without merit. The relator seeks to apply the charter provision, which requires the department of public works to keep the streets clear of obstruction, to an alleged infringement of her private rights by the elevated railway. By a mere motion to compel the department to remove structures which, at the present time and under existing circumstances, have not the slightest bearing upon any practical question, she seeks by a short cut what would be the result of a successful action in equity. She has a remedy at law and a remedy in equity. She needs no mandamus, and she is subjected to no present loss or even inconvenience. Besides, the right is not clear, and where that is the case, the party cannot have mandamus, but must resort to an action. There is no public duty imposed upon the department of public works under such circumstances. It cannot treat these structures, erected under claim of legislative authority, upon vacant lots -in a substantially uninhabited part of the city, as it would an ash barrel or a news stand in a crowded street. Questions of legal right cannot bo settled in this summary way, and the application should be denied, with costs.