The first is called an indemnity bond, the purpose of which is for the sole benefit of the owner, to secure for him the completion of the building within the terms of the contract and without extra cost to him, because of liens for unpaid subcontractors, labor and material for which he might otherwise be liable. Mason v. Company, 85 N.H. 487. The second is a performance bond, where the surety guarantees not only that the building will be completed within the contract price without extra cost to the owner, but also that payment will be made by the contractor to subcontractors and to those who furnish labor and materials. Toner v. Long, 79 N.H. 458. The bond agreement here was executed in two parts.

As previously indicated, their rights depend upon the statute. If they accept its benefits, they likewise become subject to its burdens. The statute creates their rights, and they may not be enforced at common law (Mason v. Company, 85 N.H. 487), but only by the means specified by the statute. Such creditors are accordingly remitted to the statutory procedure, including notice and petition, within the times limited.

To such a waiver the respondents have no right to object. Our attention has been called to the case of Mason v. Portland Construction Co., 160 Atl. (N.H.) 477, where the court, in its opinion, after stating the definition of surety contained in the specifications, disregarded it completely in holding that the surety on the bond was not required to pay a subcontractor where there was no express obligation in the bond or contract on the part of either the contractor or the surety to pay for labor and materials. And on this point the court said: "According to the specifications the form of the 'contract bond required' was to be that provided by the city.

And such a promise is necessary before the casualty company can be held." Mason v. Portland Const. Co. et al (N.H., 1932), 160 A. 477. "It is argued for appellants that, as the contract required Opdahl to furnish all the materials, this was equivalent to an agreement on Opdahl's part to pay for the same, and that the bond having been given to secure the faithful performance of the contract the surety company can be held liable for the amount due for materials furnished to Opdahl by appellants.