the principal. Where the liability of the surety is less extensive in amount than that of the principal debtor, questions have arisen in England and America as to whether the surety is liable only for part of the debt equal to the limit of his liability, or, up to such limit, for the whole debt. The surety cannot be made liable except for a loss sustained by reason of the default guaranteed against. Moreover, in the case of a joint and several guarantee by several sureties, unless all sign it none are liable thereunder. The limit of the surety's liability must be construed so as to give effect to what may fairly be inferred to have been the intention of the parties as expressed in writing. In cases of doubtful import, recourse to parol evidence is permissible, to explain, but not to contradict, the written evidence of the guarantee. As a general rule, the surety is not liable if the principal debt cannot be enforced. It has never been actually decided in England whether this rule holds good in cases where the principal debtor is a minor and on that account is not liable to the creditor. When directors guarantee the performance by their company of a contract which is beyond their authority, and therefore not binding on the company, the directors' liability is enforceable against them personally. Termination of liability It is not always easy to determine for how long liability under a guarantee endures. Sometimes a guarantee is limited to a single transaction, and is obviously intended to be security against one specific default only. On the other hand, it as often happens that it is not exhausted by one transaction on the faith of it, but extends to a series of transactions, and remains a standing security until it is revoked, either by the act of the parties or by the death of the surety. It is then termed a continuing guarantee. No fixed rules of interpretation determine whether a guarantee is a continuing one or not, but each case must be judged on its individual merits. Frequently, in order to achieve a correct construction, it becomes necessary to examine the surrounding circumstances, which often reveal what was the subject matter which the parties contemplated when the guarantee was given, and what was the scope and object of the transaction between them. Most continuing guarantees are either