(After stating the foregoing facts.)
The judge erred in striking the plea. The allegations of the plea do not sound in tort, but are based upon an implied contract which arose between the plaintiff and the defendant at the time of the delivery of the cars. This implied contract was to pay to the plaintiff the value of the cars, if they were destroyed by any act of the defendant which in law amounted to a conversion, or to pay the reasonable hire of the cars, although they might not have been converted, but were eventually destroyed by the ordinary and natural wear and tear. The plea seems, however, to contemplate the first contingency mentioned, and not the latter. Even if the cause of action had partaken both of the nature of a tort and of a contract, the defendant had the right to waive the tort involved in the destruction or use of the cars, and to sue for their value, basing its claim upon an implied promise to pay for them in the one case, or to pay the reasonable value of their hire in the other case. Under these circumstances the law presumes a promise to pay. Civil Code (1910), § 4406; Buchanan v. McClain, 110 Ga. 477 (35 S. E. 665). Besides, the plea contains the further allegation that the plaintiff expressly agreed to pay to the defendant the "value of the cars after they had been rendered worthless by usage. *280This express promise to pay constituted a contract which could beset off against the note; and the demurrer to the plea admits that this promise was made. For both reasons, therefore, we think it clear that the defense relied upon arose ex contractu and not ex delicto, and the court erred in striking the answer and entering up judgment on the note. Judgment reversed.