HM steam-sloop _Alecto_, Commander FW Austen, had previously, early in April, gone up, towing three heavily-laden schooners against a current of three knots and a head wind. On approaching a place called Tonelero, a number of workmen were seen throwing up batteries, clearly for the purpose of annoying the convoy on their way down. Opening her fire on them, she soon put the men to flight. She came up to the batteries on the morning of the 6th, with a strong wind and current against her, and the heavy schooners in tow. She had been accompanied all the way by a squadron of cavalry, who kept pace with her in an easy walk, halting every now and then. At two her crew went to quarters; and at forty minutes past two, having before fired a few shot, her three guns and rockets were got into full play. This was answered by the lower guns on the batteries with round shot until she reached the narrowest part, when the enemy opened with round shot and grape together. Their guns were raking her at this time from head to stern in such a way that none of her guns could be brought effectually to bear on them. In this state she remained for twenty minutes, scarcely going ahead, and receiving the fire of seven eighteen-pounders, several of which were pointed down on her decks. During this time she fired away in return at the enemy, who appeared abreast of her, every charge of grape and canister on board, and was then reduced to round shot. For a few minutes, also, she exchanged with them a sharp fire of musketry. She then went gradually ahead, and as the river widened, and the current decreased in strength, she drew out of shot, having been an hour and fifteen minutes under fire. Captain Austen, her commander, was the only person hurt, a spent grape-shot having struck him a severe blow on the thigh. Commander Mackinnon, then a lieutenant, who has written a most amusing account of the affair, says "that in going into action the men appeared to take it as a matter of course; but as the plot thickened and they warmed at the work, they tossed the long guns about like playthings, and indeed managed them in an admirable manner." This he attributes to the system taught on board the _Excellent_. The crews of the Monte Videan schooners were in a dreadful fright all the time, expecting to be sent to the bottom. On sounding the well on board the _Alecto_, a considerable quantity of water was found in the hold. When search was made, a shot-hole was discovered forward, between wind and water. This was speedily plugged. Just as she came in sight of the convoy, after her long and tedious voyage, she got on shore, and there remained for some days before she was again floated off. GALLANT EXPLOIT OF A ROCKET-BATTERY.