By the terms of the ordinance (No. 713. An Ordinance Authorizing'the Endorsement of the Bonds of the Providence and Springfield Railroad Company) the Mayor is authorized to guarantee the payment of the bonds, only by and with the advice of the committee on the city debt. Their advice is consequently necessary to the Mayor’s action. This being so, the committee on the city debt is a part of the instrumentality for the carrying out by the city of the action which it is the purpose of the bill to enjoin. We think, therefore, that, in accordance with well settled principles, the committee on the city debt were properly made parties to the bill. Story’s Eq. PL § 159. Sully *537 v. Drennan, 113 U. S. 287. Their demurrer to the hill is overruled.

The bill avers that the bonds have all been sold and negotiated. If this he so, the Providence and Springfield Railroad Company have ceased to have any interest in the bonds, and no relief being prayed against it, the complainants could not properly have made it a respondent. Had they done so the bill would have been clearly demurrable.

The Judiciary Act, cap. 20, § 16, provides that any person, on making it appear that he is interested in the subject matter of a suit, may be allowed to become a party. If the Providence and Springfield Railroad Company are still the holders of the bonds, as claimed, when that fact appears, it may he permitted by the court to become a party to the suit, if the complainants do not voluntarily amend their bill by making it a party; but on the allegations of the bill, of which alone, on demurrer, we can take cognizance, we do not think that the Providence and Springfield Railroad Company is entitled to he made a party; and, hence, the demurrer of the. city of Providence, incorporated in its answer, based on the ground that the bill is defective for the nonjoinder of that company, must also he overruled.