Williamsburg, March 22.

It is an undoubted fact, that between 8 and 9000wt. of gunpowder is just brought into this colony, from one of the French islands, with a number of fieldpieces, four and six-pounders, some muskets, &c. Several French gentlemen likewise came in the vessel, one of whom, shortly after their arrival set out for Philadelphia. While a couple of tenders were on their way up James river, last Thursday night [March 14] which was very dark and stormy, one of them got fast aground below Jamestown, within a small distance of the shore, and the crew, finding it impracticable to get her off, stayed on board till next morning, when all hands left her, and rowed to the other tender, leaving behind a number of cannon balls, a quantity of salt, some sailors clothes, &c. They then proceeded up to a plantation of mr. Harrison's of Brandon, from whence they stole eight steers out of a cart, and twelve lean cows, which they slaughtered and took with them, for the use .of lord Dunmore's hungry fleet and army, robbing the overseer likewise of all his household goods, stripping the negro cabins, and carried with them, by force, two valuable negro men, as recruits, we suppose, for the Royal Regiment of Black Fusi leers. About ten days ago, a sloop bound from Hispaniola to Philadelphia, the property of mr. Beveridge, merchant in that city, and commanded by capt. Forrester, was taken in the bay by a tender belonging to the Roebuck man of war, and one Rogers, a midshipman, with five seamen, were put on board to conduct her to Norfolk; at the same time taking out all the hands, except the mate and a boy. In her voyage thither, one of the casks of wine in the hold becoming leaky by some accident, the midshipman and his party went down to stop the leak, when the mate and boy, with great address, shut down the hatches and secured the prisoners, and then pushed to the Eastern Shore with the vessel and cargo, the latter worth at least 4000£ sterling. Captain Hammond, on hearing of this affair, ordered capt. Forrester, who was on board the Roebuck, up to the prison ship at Norfolk, in a pilot boat, under the escort of a midshipman and six hands; but the vessel running aground on an oyster bank, two miles below lord Dunmore's ship, the midshipman ordered one of the seamen into a canoe to do something for the relief of the vessel, when capt. Forrester seized the opportunity, and, leaped into the canoe, cut the painter with a jack-leg knife, on which she swung off with the tide; then turning to the seaman, swore he would cut his throat if he offered to obstruck him in his escape. This menace quieted the fellow till capt. Forrester had paddled about 100 yards, when, finding his escape practicable, he pulled with all his might, and both got safely ashore, amidst a cloud of curses and imprecations from the midshipman and sailors. The captain, and his comrade whom he had taken, have gone to Accomack, to look after the vessel, and to dispose of the cargo to the best advantage.

Capt. Forrester informs, that the Kingfisher is gone round to Boston, to bring a number of ships of war up Delaware river, to prevent the Philadelphians from making any farther preparations for the defence of their city; it being determined upon, it seems, that the grand attack shall be made upon Philadelphia, as soon as the fleet and troops arrive from England, but we hope will prove equally abortive with the rest of the cursed ministerial schemes to enslave America.

The Otter sloop of war, and two tenders, which have been lying at the mouth of Patuxent, and cruising in the bay, for some time past, took several prizes, and burnt a shallop loaded with oats; and, their audacity increasing with their successful piracy, capt. Squire took it into his head to go up to Baltimore, with the tenders and prizes, with the view, it was supposed, to take or destroy the Defence privateer which had been fitting out at that place. Capt Nicholson, however, the commander, having got intelligence of his design, immediately got his Defence ready, manned with a number of brave Hearts of Oak, and towed down the river, to give battle to the Otter, several small vessels attending, crowded with men, to lend their assistance, if it should be wanted. Upon being discovered bearing down by the tenders, they pushed off with precipitation, abandoning three or four small prize vessels, with a large ship they had taken loaded with wheat and flour, commanded by one [Jonathan] Hudson. The Defence having manned the prize, and seeing the Otter get under way, clued up her courses and prepared for battle, expecting her to come up; but the Otter having lain about two hours, as if wanting capt.Nicholson to come down, at length bore away, and in the afternoon came to anchor off Annapolis. Capt. Nicholson con tinued his station some time; and, having performed this gallant action, re turned with the prizes to Baltimore.