The scene is placid now, but almost 200 years ago the sky over Yorktown was filled with shells. Gen. George Washington and his French allies, 16,000 strong, were laying siege to Lord Cornwallis' British force, and their artillery rained death and destruction on the embattled British day and night.

"The whole peninsula trembles under the incessant thunderings of our infernal machines," one observer wrote.

Gradually, under the barrage, the British weakened. Cornwallis was running out of shells for his guns. The Americans and French captured two key redoubts, built a new siege line and redoubled their bombardment of Yorktown.

Finally, with growing numbers of sick and wounded, with supplies dwindling and no hope of relief or reinforcement from without, Cornwallis sent an officer out with a white flag. Two days later, at 2 p.m. on Oct. 19, 1781, the defeated British troops and their German allies marched out of the demolished town to surrender.

The American Revolutionary War, for all practical purposes, was over. Cornwallis' surrender convinced the British government of the futility of further hostilities and led it to sue for peace.

Today that battlefield where so much history was made is almost park-like, its trenches and emplacements softened with a grassy cover, its perimeters bordered with great trees that grow to the edge of the broad York River. Some 400,000 persons visit here annually, and next year many thousands more are expected when Yorktown celebrates its bicentennial.

That event is still in the planning stage, but if past celebrations are any indication, it should be impressive. In 1881, on the 100th anniversary of the surrender, President Chester A. Arthur, his cabinet, the Congress, the Supreme Court and the high military brass attended the celebration, along with high French and German officials.

In 1931, on the 150th anniversary, more than 200,000 visitors converged on Yorktown to hear President Herbert Hoover speak. Also on hand were descendants of some of the most famous participants, including the Marquis de Rochambeau (related to the French commander), the Comte de Chambrun (related to the Marquis de Lafayette) and the Marquis de Grasse (related to the French admiral), as well as Marshal Petain of France and the governors of the 13 original states.

National Park Service officials are confident that the president of the United States will attend the bicentennial fete. "We hope to have the presidents of France and Germany as well," said Jimmy Sullivan, park superintendent.

A four-day celebration is planned, Oct. 16-19. During that period, some 6,000 uniformed members of recreated colonial military units from the 13 original states will encamp there. Military parades, encampment demonstrations, naval maneuvers and fireworks are planned. On the anniversary day, Monday, Oct. 19, the surrender ceremony will be recreated. It is expected that the president of the United States will speak there, along with other high-ranking American, French, British and German leaders. a

A colonial festival also is in the making. Colonial lifestyles would be demonstrated, not only those aspects presented at nearby Jamestown and Williamsburg but quarter-horse racing and jousting as well.

A budget of about $2 million has been set for the project, with the park service putting up about $250,000, the state of Virginia $100,000 and the rest to come from the sale of medallions and other souvenirs, food and concessions. At least two hotels -- the Chamberlin in Hampton and the Duke of York in Yorktown -- are already booked for the 1981 weekend celebration.

Not all events at Yorktown will take place on that climactic weekend. Earlier in 1981, the park service hopes to have French and American warships visit Yorktown to commemorate the vital role of the French fleet under De Grasse in sealing off Cornwallis' possible escape by sea. A contingent of tall ships is expected sometime in the summer.

But the main attraction, of course, will be the battlefield itself, and it is a substantial one. There is a mystique about a battlefield, even a long-quiet one. You can feel the pull of history when you walk into the very redoubt where Washington signed the surrender documents, adding, "Done in the trenches before York Town . . . ."

You feel it when you visit the Moore House, where the articles of surrender were negotiated by two British officers and two Allied officers, one American and one French, and on the surrender ground, where Cornwallis' second in command, Gen. O'Hara, handed over his sword to Washington's No. 2, Gen. Lincoln.

A good way to see the siege in perspective is to take the guided tour that rangers offer at intervals during the day. You can also take a free park service bus around the battlefield, during which you'll hear a commentary about the siege and make four stops.

Or you can simply drive yourself to points of interest on the battlefield, virtually all of which you can see from the roof of the Visitor Center. "It is a very small battlefield," observed Sullivan. Indeed it is. The whole of it could fit in one very small pocket of the Vicksburg, Miss. battlefield. o

Save some time for the Visitor Center. It has some particularly interesting exhibits, including George Washington's own tents, the Hessian colors surrendered to Washington, various muskets in use at the time, swords and mortars, multimedia presentations and a reconstructed quarter of a British frigate of the 1780s into which you can walk and see how the sailors of the day lived and worked and fought.

Historical dramas relating to Yorktown are presented at Nelson House in Yorktown. Thomas Nelson was a signer of the Declaration of Independence and a general of the militia. When he was invited by Lafayette to aim the guns during the seige, Nelson pointed to his own brick mansion, "the best one in the town," feeling that was probably where Cornwallis would make his hedquarters. His home still has cannon balls lodged in its brick walls.

Also in town are several other old structures, including the old customehouse, the colonial Grace Church, Archer cottage, Dudley Diggs home, Somerwell House, Swan Tavern and Cornwallis' cave, where the British commander took refuge during the shelling. On the banks of the York River is the 95-foot-high Victory Monument, built at the time of the centennial.

A re-creation of a military encampment of the period is presented at the Yorktown Victory Center, a state facility which charges an admission. The attraction has multimedia exhibits, a museum and a 28-minute film on the siege and surrender.

Visitors to Yorktown can now reach it again via the Colonial Parkway, part of which had been closed for bridge repair for almost a year. It was fully reopened Oct. 17. The parkway, also administered by the park service, connects the three great historic areas on this Virginia peninsula: Yorktown, Jamestown and Williamsburg. All are worth visiting.