A public contract need not be let to the "lowest" bidder unless the statute requires it.1 The statutes often require the contract to be let, after advertising, to the "lowest," "the lowest and best," or "the lowest responsible" bidder.2 A contract let without complying with this requirement is unenforceable.3 Since the purpose of such provisions is to secure to the public corporation the full benefit of free competition, a change cannot be made in a bid after the time set for receiving bids,4 even if only one person has submitted bids.5 A contract is void if provisions favorable to the contractor are added after the bids are in, differing from the specifications on which such bids are made.6 Such provisions do not prevent a city from constructing public works under the direction of its own engineers and officers.7

These provisions are for the benefit of the public. The lowest bidder cannot sue at law for profits which he would have made had his bid been accepted.8 The lowest bidder may enjoin the council from accepting a higher bid.9 Property owners who are obliged to pay more for an improvement than they other-wise would have been obliged to pay, may recover against a city which has voluntarily released the lowest bidder, whose bid has been accepted, and accepted the bid of a higher bidder, for the difference between the two bids.10 If bids have been advertised for on' two different specifications, intended as alternative for the same work, a provision requiring the letting of the contract to the lowest bidder does not bind the city to select that specification on which the lowest bid is given.11

5 Mahon v. Luzerne Co., 197 Pa. St. 1; 46 Atl. 894.

6 State ex rel. Moreland v. Passaic, 63 N. J. L. 208; 42 Atl. 1058.

1 Pacific Bridge Co. v. Clackamas County, 45 Fed. 217; Riehl v. San Jose, 101 Cal. 442; 35 Pac. 1013; Hartford v. Light Co., 65 Conn. 324; 32 Atl. 925; Mayo v. Hampden, 141 Mass. 74; 6 N. E. 757; Kundinger v. Saginaw, - Mich. - ; 93 N. W. 914; State v. Lincoln County, 35 Neb. 346; 53 N. W. 147; State v. Dixon County, 24 Neb. 106; 37 N. W. 936; Oakley v. Atlantic City, 63 N. J. L. 127; 44 Atl. 651. It was said to be the duty of the public corporation to let the contract to the lowest bidder unless by statutory authority in State v. Cornell, 52 Neb. 25; 71 N. W. 961.

2 Mueller v. Eau Claire Co., 108 Wis. 304; 84 N. W. 430.

3 Fox v. New Orleans, 12 La. Ann. 154; 68 Am. Dec. 766. So where bonds are sold at private sale without giving a chance to bid. Roberts v. Taft, 116 Fed. 228; Roberts v. Taft, 109 Fed. 825; 48 C. C. A. 681.

4 Fairbanks v. North Bend, -Neb.- ; 94 N. W. 537.

5 Le Tourneau v. Hugo. 90 Minn. 420; 97 N. W. 115.

6 Diamond v. Mankato, 89 Minn. 48; 61 L. R. A. 448; 93 N. W. 91.

7 Home, etc., Co. v. Roanoke, 91 Vt. 52; 27 L. R. A. 551; 20 S. E. 895.

8 Talbot Paving Co. v. Detroit. 109 Mich. 657; 63 Am. St. Rep. 604: 67 N. W. 979.