The attack was made by the combined fleets, consisting of five sail of the line, eighteen or twenty frigates and smaller vessels, besides five bomb-vessels and several rocket-boats, carrying in all about one thousand guns.  The armament of some of the smaller vessels is not given, but the guns of those whose armaments are known, amount to over nine hundred.  The harbor and defences of Algiers had been previously surveyed by Captain Warde, royal navy, under Lord Exmouth’s direction; and the number of the combined fleet was arranged according to the information given in this survey—­just so many ships, and no more, being taken, as could be employed to advantage against the city, without being needlessly exposed.  Moreover, the men and officers had been selected and exercised with reference to this particular attack.

From the survey of Captain Warde, and the accompanying map, it appears that the armament of all the fortifications of Algiers and the vicinity, counting the water fronts and the parts that could flank the shore, was only two hundred and eighty-four guns of various sizes and descriptions, including mortars.  But not near all of these could act upon the fleet as it lay.  Other English accounts state the number of guns actually opposed to the fleet at from two hundred and twenty to two hundred and thirty.  Some of these were in small and distant batteries, whereas nearly all the fleet was concentrated on the mole-head works. (Fig. 36.) Supposing only one broadside of the ships to have been engaged, the ratio of the forces, as expressed by the number of guns, must have been about as 5 to 2.  This is a favorable supposition for the ships; for we know that several of them, from their position and a change of anchorage, brought both broadsides to bear; moreover, at no one time could all the guns of the water fronts of the batteries bear on the attacking ships.  The Algerine shipping in the harbor was considerable, including several vessels of war, but no use was made of them in defence, and nearly all were burnt.  The attacking ships commanded some of the batteries, and almost immediately dismounted their guns.  The walls of the casemated works were so thin as to be very soon battered down.  Most of the Algerine guns were badly mounted, and many of them were useless after the first fire.  They had no furnaces for heating shot, and, as “they loaded their guns with loose powder, put in with a ladle,” they could not possibly have used hot shot, even had they constructed furnaces.  The ships approached the forts, and many of them anchored in their intended position, without a shot being fired from the batteries.  The action commenced at a quarter before three, and did not entirely cease till half-past eleven.  The ships then took advantage of the land breeze, and, by warping and towing off, were able to get under sail and come to anchor beyond reach of the land-batteries.  Negotiations were again opened, and the Dey surrendered the Christian slaves and yielded to the terms of the treaty.