WASHINGTON, Circuit Justice (charging jury). The foundation of all insurances, unless of the wager kind, is the real value of the thing insured; and the only difference between a valued and an open policy, is, that, in the first, the parties agree upon the value; and in the latter, the assured is bound to prove it. But, a new principle is now attempted to be introduced; namely, that the prime cost, instead of the real value, is to be the measure of the indemnity.

The prime cost, or invoice price, may, in most cases, be prima facie a very proper criterion; and, in the case of goods, the latter is the proper measure of the value. The assured cannot object to it. because the invoice is tantamount to an agreement on his part, that that is the value; and it must, in all cases, be so near to the value, that it is very properly considered as the criterion.

But, as to the prime cost, this may often vary very considerably from the invoice price; for instance, a cargo of flour may, when shipped, and invoiced, be worth double as much as it cost; and, can it be contended, in such a case, that the prime cost would furnish the-rule? Equally unjust, and repugnant to, the-principle of insurance, would it be to say, that, if a vessel be really worth twice as-much as the owner gave for her, that the-latter should be the criterion of value.

If' the prime cost is to furnish the rule, then,, when the builder of a vessel insures, he must prove not what was her value, but what she-cost him. The prime cost is a good rule,, where no better is-furnished; and, as m this: case there is no proof of -her real value in: Jamaica, the jury may probably adopt the-sum at which she sold, as the value of her.. But, if they, from the evidence, are satisfied' that she was worth more, they are not bound by what was given for her. I will add farther, that the rule contended for by these defendants, would, in many cases, operate most injuriously against underwriters.

The jury found for the plaintiffs upwards of 2300 dollars.