specially concúrring:
We concur in the affirmance of the judgment of the Appellate Court on the ground that appellants are now es-topped to insist upon the vacation of the alley, but we do not concur in that portion of the opinion holding that the vacation was in the first instance a valid exercise of the power of the city council. The ordinance vacating the alley was passed for the purpose of permitting Wieboldt to erect a building on the ground vacated, to be occupied by him in the conduct 'of his own private business. The inducement for the vacation was the agreement of Wieboldt to pay one-half the expense of paving Bauwans street from North Ashland avenue to Elk street, and to pay the city, annually, $100. This court has repeatedly held that cities hold their streets and alleys in trust for the use and benefit of the public, and they have no power to vacate them for the purpose of devoting them to the exclusive use and benefit of a private person. Smith v. McDowell, 148 Ill. 51; Pennsylvania Co. v. City of Chicago, 181 id. 289.