Collings v. Hope

¶1charged the jury. What is called the custom or usage of trade, is the law of that trade; and to make it at all obligatory, it must be ancient, (sufficiently so at least, to be generally known,) certain, uniform, and reasonable. A usage of so doubtful authority as to be known only to a few, and where merchants engaged in the trade differ as they do in this case, as to the existence of it, can never be regarded. The one now set up, is an unnatural one; for, although the shipper may consent to let the agent make the insurance, yet in general, he would prefer making his own bargain; and though the agent may insure to the amount of his advance, for the safety of his principal, yet he may decline doing it, if he is willing to trust to the general credit of the shipper. Beyond the sum advanced, he certainly cannot insure, without an express authority from the owner of the cargo; and this circumstance is strong to prove, that wherever the agent insures, he obtains such an authority from the shipper. This appears to have been the practice of this agent But even if the custom had been fully proved, this case would be an exception from it, as Claudius not only declined insuring, but the defendant undertook to insure. Verdict for plaintiffs.