1. Art. 7, sec. &, par. 1, of the constitution of this State, embodied in Civil Code, § 5883, declares: “All taxation shall be uni*468form upon the same class of subjects, and ad valorem on all property subject to be taxed within the territorial limits of the authority levying the tax, and shall be levied and collected under general laws." Under the constitution, art. 7, see. 2, paragraphs 2 and 4 (Civil Code, §§ 5884, 5886), no property can be exempted from taxation other than that specifically mentioned in par. 2. The property involved in the present case belongs to a class which is nonexempt. It is as unlawful to sell an exemption as it is to give it away. Municipal authorities can no more bestow on an owner of property subject to taxation an exemption therefrom for a consideration than they can bestow it gratuitously. It is true that municipal authorities, where they have the power to pay for certain privileges, have the right to make a binding contract whereby they agree to pay for such privileges an amount equal to the taxes which the owner of such property is liable to pay, provided that the amount of such taxes is a reasonable and fair compensation for the privileges contracted for, and the contract does not constitute an evasion of the laws prohibiting exemption from taxation. Such a contract does not exempt any property from taxation, or prevent .the city from collecting the taxes assessed against the same. Under a contract of this character the city can collect from the owner of property the taxes assessed against it, although the city might owe the owner of the property an amount equal to the taxes. Under such a contract there is no agreement to exempt property from taxation, or to refrain from the collection of taxes thereon. But there is a radical difference between a valid contract of the nature referred to, and one whereby the authorities agree to charge the owner of property no taxes in consideration of privileges conferred by the owner upon the municipality. If the municipal authorities have the right to buy privileges of a certain character, they have the right to pay therefor any reasonable sum agreed upon, or a sum to be measured in a definite way by the .amount of taxes which would be assessed against the owner, or against any other person, provided, as before stated, that the contract is reasonable and fair, and is not an attempt to evade the constitutional prohibition against exemption. A contract, however, which purports to bind the city to collect no taxes from the owner of property, in return for a valuable consideration, is clearly a sale of an exemption of such property by way of commutation of the tax, and is illegal under the *469provisions, of tlie constitution above referred to. The fact that the. city, under a contract of this nature, may have received from the tax debtor benefits which in value equal or exceed the amount of the tax due can not deter the city from enforcing the collection of such tax, and any contract of this character purporting to bind the city so as to prevent the collection of its tax revenue is unlawful. Cartersville Water Company v. Mayor, 89 Ga. 689 (16 S. E. 70). Upon a careful consideration of the contract referred to in the statement of facts, we construe it to be an attempt by the city to sell to the mills an exemption of its property from taxation over $850, in consideration of certain water privileges and other benefits given the city by the mills, and therefore unlawful.
2. In City Council of Dawson v. Dawson Water Works Company, 106 Ga. 696 (32 S. E. 907), it was ruled: “Without the preliminary sanction of a popular vote as required by the constitution, a municipal corporation can not contract for a supply of water, on the credit of the city, for a longer period than one year; and a contract which by its terms is to run for twenty years, each year’s supply 'to be paid for semi-annually from year to year, is operative from year to year so long as neither party renounces or repudiates it.” It was further ruled in that case, “The City Council of Dawson has a right to make a contract to supply the city with water for one year, provided they have in the treasury of the city a sum sufficient to' pay therefor, which may be lawfully appropriated for that purpose, or if such sum can be secured by lawful taxation levied during the year in which fhe contract is made. While a contract for a longer space of time is illegal, yet where the other parties to such a contract have complied with their part by erecting a plant at great expense in order to furnish the city with water, the city is liable for the amount stipulated in the contract for each year that it received the benefits thereof.” The contract we are considering, however, independently of its feature of creating an unauthorized debt, is illegal because in it the city undertook to exempt the property of the mills from taxation. The pleas of the defendant municipality, properly construed, are to the effect that its authorities each year charged no taxes against the mills over and above the sum of $850, and the mills charged and collected from the city nothing for the privileges referred to in the contract as furnished to the city by the mills, and that all of this was done *470pursuant to tlie contract outlined in the statement of facts. It is alleged in the answer of the Crown Cotton Mills that it would be useless to require the municipal authorities to assess its property and collect taxes thereon, when such action could only result in the city refunding the amount collected as taxes to compensate the mills for the benefits which it had conferred upon the city. The municipal authorities object to their being required to enforce the payment of taxes by the mills, on the ground that the latter, under the contract, owes the city no taxes. But the contract is illegal; and the municipal authorities can not avail themselves of it as an excuse for the non-performance of their duty to collect taxes which the mills are due under the law. To permit the city to refuse to collect taxes on the property of the mills because of the contract would amount to a recognition of its validity, and would be an enforcement of it by the courts as though it were legal. The municipal authorities do not in their answer admit that the city owes the mills anything other than by virtue of the contract which we have declared to be illegal. The mere fact that the city owes it an amount equal to or greater than the amount of its municipal tax does not prevent the city from collecting the taxes due by the former. Cartersville Water Company v. Mayor, supra; Wayne v. Mayor, 56 Ga. 448. The resolution of the municipal authorities, copied in the statement of facts, correctly interpreted, means that by reason of the contract they are willing to treat the amounts respectively due from the mills to the city, and vice versa, for the year 1909 and previous years as settled. The allegation in the amendment immediately preceding the copy of the resolutions set out in the amendment is as follows: “The present mayor and council, acting on this line, have passed a resolution ratifying the contract for the present year, and, as far as their power lies, ratifying the same for jiast years, which resolution is as followsThis allegation, es2Decially in view of the preceding allegations in the amendment, shows that whatever was attempted to be done by the resolution was in pursuance of the contract. There is no allegation in any of the answers that any actual settlement has been had between the city and the mills except in pursuance of the illegal contract, the only averments in this'respect meaning that each year, under the contract, they'- had treated the taxes as being settled in consideration of the benefits received. Had there been, independ*471ent of this contract, any settlement between them of their respective obligations, whether the same would be binding or not, is not before ns for consideration, and therefore not decided.
3. The plaintiff complains that the presiding judge' erred in making the Crown Cotton Mills a party defendant, upon the motion of the municipal authorities. The mills were vitally interested in the question as to whether or not the contract between it and the city was valid, and whether or not the latter should proceed against it for the collection of the taxes alleged to be due. In the answer of the mills it was stated: “this defendant has no objection to being made a party defendant to said action, inasmuch as it is interested in the questions sought to be adjudicated by said petition.” In 26 Cyc. 415, it is said: “Individuals or corporations who have a special legal interest in the subject-matter' of a mandamus proceeding and whose rights will be collaterally determined by a judgment awarding the writ may properly be joined as parties respondent, and are generally required to be so joined.” The court committed no error in making the mills a party defendant.
4. The plaintiff made a motion to make the mandamus absolute and to strike ail of the answers of the defendants. In the case of Southern Ry. Co. v. Atlanta Stove Works, 128 Ga. 207 (57 S. E. 429), in referring to the decisions in the cases of Hollis v. Nelms, 115 Ga. 5 (41 S. E. 263), Stromberg v. Bisbee, 115 Ga. 346 (41 S. E. 573), and Ray v. Anderson, 117 Ga. 136 (43 S. E. 408), Justice Evans said: “None of these cases were decided by a full bench, and we are not absolutely bound thereby. We think the reasoning on which they are based is fallacious. See Crew v. Hutcheson, 115 Ga. 533 (42 S. E. 16); Kelly v. Strouse, 116 Ga. 890 [43 S. E. 280].. A motion to make a mandamus absolute necessarily involves a determination that the averments in the answer either afford or do not afford a sufficient reason in opposition to the issuance of the writ. If the answer avers matters which set forth no defense to making the rule absolute, in this day of directness in formulating the substantial issues by means of the pleadings its sufficiency is’ tested by the motion to make the rule absolute. . . The assignment of error that the court erred in making the mandamus absolute, because the allegations of the answer raised certain issues of fact which should first have been submitted to a jury, raises the question whether any issue of fact was made by the an*472swer.” No issues of fact were made by the answers of the defendants, and, the matters therein set forth offered no sufficient reason why the mandamus absolute should not have been granted. The court committed error in refusing the motion.
