Hines, J.

(After stating the foregoing facts.)

It is insisted that the plaintiffs had an ample remedy at law by affidavit of illegality, as provided by the act of August 19, 1919 (Acts 1919, p. 867), under which this paving was done; and that for this reason the trial judge erred in granting an interlocutory injunction. The affidavit of illegality provided by this *430act furnishes a sufficient remedy at law, and precludes the grant of injunctive relief, where an individual owner of land, abutting upon streets which have been paved under this act, seeks to resist the enforcement of an execution based upon an assessment against his property to cover his share of the cost of the improvement, upon the ground that the assessment, or some part thereof, is unlawful. Rice v. Macon, 117 Ga. 401 (43 S. E. 773); Mayor &c. of Gainesville v. Dean, 124 Ga. 750 (53 S. E. 183). Where there is a mass attack by several owners of abutting property, upon the legality of an assessment for street paving, the ground of attack being common to all, the remedy by illegality is not as adequate and complete as the remedy by injunction. In such a case, to prevent multiplicity of suits, equity will interfere by injunction. Sanders v. Gainesville, 141 Ga. 441 (81 S. E. 215); Wilkins v. Savannah, 152 Ga. 638 (111 S. E. 42). So the trial judge, in granting an interlocutory injunction, did not err for the reason that plaintiffs had an adequate remedy at law.

It is next urged by counsel for-the plaintiffs in error that the trial judge should have refused a temporary injunction, on the. ground that the plaintiffs had not paid or offered to pay the amounts which they admit to be due by them upon the assessments levied by the city to cover their portions of the cost of paving these streets. It is familiar law that he who seeks equity must do equity. Civil Code (1910), § 4521. So where owners of property abutting upon streets attack an assessment, not on the ground that it is wholly unlawful, but only on the ground that it is excessive, they should pay or offer to pay what they admit to be due, in order to contest that which they claim to be excessive. This is a sound rule of equity. National Bank v. Kimball, 103 U. S. 732 (26 L. ed. 469); Lanham v. Rome, 136 Ga. 398 (71 S. E. 770). In their petition the plaintiffs allege that they had offered to pay to the city- and the contractor one-third of the cost of paving these streets, and that they had tendered and now tender such cost. Their petition was duly verified, and was read in evidence on the hearing. So the trial judge had before him, not only this allegation of the offer of the plaintiffs to pay what they admit to be due, but proof of such offer. The fact that this allegation was denied by the defendants created only *431a conflict in the evidence, which the trial judge settled in favor of the plaintiffs.

This brings us to decide the important and controlling question in this case; and that is whether or n,ot the city was justified in embracing in its assessments against these owners and their lands the cost of paving the twenty-foot roadway which the Highway Department of the State and the county constructed through the portions of these streets which the city resolved to pave by its ordinance of June 9, 1924. The City of Camilla is authorized to assess the cost of paving and otherwise improving its streets against the owners of real estate abutting on said streets, as well as against said real estate, provided the amounts so assessed against property owners for said purposes shall in no instance be more than two thirds of said cost. Ga. Laws 1919, p. 867. The term “cost,-” as used in this act, clearly means the amount which the city had to expend in paving its streets. If the city expended nothing in paving these streets, or portions thereof, it would not be authorized to make an assessment against the property abutting thereon to cover the cost of such improvement, when the same was done by the county and the Highway Department of the State in constructing a State highway, and when the city did not pay such cost and was in no way liable for such cost to the county and the State Highway Department or either of them. The fact that the county and the State Highway Department agreed to pave a roadway of twenty feet through these streets, with funds derived from the State and the Federal government, in order to assist the city in improving these streets, would not justify the municipality in embracing in its assessment the cost of paving such roadway. The city could only include in its assessment the cost incurred by it in paving the remainder of the streets. The benefit flowing from the constructing of this roadway inured to the benefit of the owners of property abutting on these streets as well as to the municipality.

This question has not heretofore been before this court for decision. In Bacon v. Savannah, 86 Ga. 301 (12 S. E. 580), this court was dealing with the power of the City of Savannah to pave a portion of the width of a street without requiring a street-railway to pave its track in said street and two feet on either side thereof at their own expense. This court held such proceeding legal. In *432delivering the opinion of the court Chief Justice Bleckley said that the owners of property abutting on the street could not be assessed for the cost of paving the track of the street-railway and the two feet on either .side thereof, whether made or not. This question was not before this court in Mayor &c. of Washington v. Faver, 155 Ga. 680 (117 S. E. 653). When the case cited was again before this court in Faver v. Mayor &c. of Washington, 159 Ga. 568 (126 S. E. 464), this question was not before this court for decision. Among the points of law which perplexed and divided this court when that case was before this court the second time was the question of the effect of section 7 of article 5 of the act of August 18, 1919 (Acts 1919, p. 251), which provides for the reimbursement of counties for money expended in the construction of State-aid roads, and the issuing by the State Highway Department of certificates to the County of Wilkes for the full cost of paving the streets of the City of Washington, upon the assessments levied by the city against the property abutting upon the streets paved. The majority of the court held that the fact that the State Highway Department had issued to the County of Wilkes certificates under the provision of the above act for the full cost of paving these streets would not relieve the owners of abutting property from the payment of assessments levied by the city for the cost of such pavement, it not being alleged that the certificates had been paid and that the city had been reimbursed for the payment of the cost of paving these streets. That question is not the one with which we are confronted in this ease. We are of the opinion that the City of Camilla, not having made any expenditure for paving this roadway of the width of 20 feet through the streets for the paving of which it levied the assessments involved in this case, was without authority to embrace in such levy the cost to the county and State Highway Department of the paving of this roadway; and that the trial judge properly enjoined the collection of so much of this assessment as embraced the cost of paving this roadway.

Counsel for the defendants requested the trial court to provide by order that the city be allowed to reassess the owners of property abutting on these streets and the property itself, so as to include certain expenditures incurred by the city in lowering water-pipes in these streets, which became necessary in order to *433pave the same, and the further cost of grading, curbing, and paving the intersections of these streets, which was not included in the original assessments against the plaintiffs. The court refused to pass such order, and to this ruling the defendants excepted. As there has been no legal assessment against the several parcels of real estate, by reáson of the fact that the cost of paving this roadway was included in the assessment made by the city against the owners of abutting property and the property itself, it becomes necessary for the city to make a reassessment, showing the total cost of the work of paving the portions of these streets not embraced in said roadway, and the apportionment of two thirds of such cost against the owners of abutting parcels and the parcels themselves. All legitimate items of such cost can be embraced in such reassessment. Bacon v. Savannah, 91 Ga. 500 (17 S. E. 749). The right of the municipality to make this reassessment is not de-' pendent upon authority granted by the trial court, but must be derived from the charter of the municipality. The exercise of this right must be evidenced by municipal legislation. So the judge did not err in refusing to pass an order allowing the city to embrace in its previous assessment the items named. This should be done in accordance with the method pointed out in the case last cited. Upon the right of the city to embrace the cost of paving intersections of streets, see Kaplan v. Macon, 144 Ga. 97 (86 S. E. 219). All questions growing out of such reassessment can be heard and determined upon the final hearing of the matters involved in this case.

Judgment affirmed.

All the Justices concur, except Gilbert, J., absent for providential came.