Letters received both from Madrid and Algiers, while I was in London, having suggested that treaties with the States of Barbary would be much facilitated by a previous one with the Ottoman Porte, it was agreed between Mr. Adams and myself, that on my return, I should consult on this subject the Count de Vergennes, whose long residence at Constantinople rendered him the best judge of its expediency. Various circumstances have put it out of my power to consult him, till to-day. I stated to him the difficulties we were likely to meet with at Algiers; and asked his opinion, what would be the probable expense of a diplomatic mission to Constantinople, and what its effect at Algiers. He said that the expense would be very great, for that presents must be made at that court, and every one would be gaping after them: and that it would not procure us a peace at Algiers one penny the cheaper. He observed, that the Barbary States acknowledged a sort of vassalage to the Porte, and availed themselves of that relation, when any thing was to be gained by it; but that whenever it subjected them to a demand from the Porte, they totally disregarded it: that money was the sole agent at Algiers, except so far as fear could be induced also. He cited the present example of Spain, which, though having a treaty with the Porte would probably be obliged to buy a peace at Algiers, at the expense of upwards of six millions of livres. I told him, we had calculated from the demands and information of the Tripoline ambassador, at London, that to make peace with the four Barbary States would cost us between two and three hundred thousand guineas, if bought with money. The sum did not seem to exceed his expectations. I mentioned to him, that considering the uncertainty of a peace, when bought, perhaps Congress might think it more eligible to establish a cruise of frigates in the Mediterranean, and even to blockade Algiers. He supposed it would require ten vessels, great and small. I observed to him that Monsieur de Massiac had formerly done it with five: he said it was true, but that vessels of relief would be necessary. I hinted to him that I thought the English capable of administering aid to the Algerines. He seemed to think it impossible, on account of the scandal it would bring on. I asked him what had occasioned the blockade by Monsieur de Massiac: he said, an infraction of their treaty by the Algerines.