There is error only in the charge. By the terms of the contract, the quantity of stone delivered was to be ascertained by “ the engineer of said canal.” But there were three; a principal engineer, a principal assistant, and a sub-assistant. So that we have the common case of a latent ambiguity, and it was *367for the jury to determine from the evidence which of them was meant. Perhaps, as the business of official measurement for payment of the estimates was within the province of the sub-assistant, the parties had him in view, being content to commit the measurement, in their private matter, to him who was intrusted with its measurement by the government. Still, that is no more than a consideration for a jury. It is very certain, however, that Sallada was not the person to whom the measurement was referred; for he was not the engineer in any sense of the contract, and his work could be resorted to only in case the work of the person designated in the contract could not be had. If the latter were dead, or unwilling to act, evidence aliunde might be received to prevent a failure of justice. But that might or might not be the case here; and the cause ought to have been put with that instruction to the jury.

Judgment reversed, and venire de novo awarded.