IT IS NOON in Harvard Yard, and for the most part, the drilling has stopped. Construction crews, breakage from their work on the Yard's water main, lounge in the shade of tall elm trees to eat their lunch.

Inside the deep trench by Harvard Hall, wearing a yellow hard hat, John N. Stubbs '80 is still busily filling shallow cardboard boxes with trash--mostly small white tubes and shards of broken glass and pottery. One box is nearly fled with large chunks of broken glass, the remains of wine bottles.

The bottles, he says, were probably discarded by undergraduates in the eighteenth century. "The yard was by no means dry at this time." Stubbs notes.

"it's definitely other peoples' garbage we're going through here," says Stubbs, a Harvard archaeologist who recently received is Ph.D. Here.

Since construction began in early summer, Stubbs has worked at the water main site. Every day workers big through the Yard, Stubbs is there, monitoring the work and scouring the soil for clues to Harvard's past.

This portion of the Yard--"the backyard of the College"--is rich with artifacts, now-valuable trash, from as far back as the 1690s, Stubbs says.

In the earliest days of Harvard, New England citizens generally dumped debris just outside their back doors, he says. "The backyard tended to be where people threw away their junk. They literally tossed it away."

From within the gaping hole, it is easy to pick out the layers of dirt. One strip has never been disturbed, even by later utilities work in the Yard. Most of the riches in that level of dark soil date back form about 1700 to about 1760, he says. Stubbs has found saucers and pottery, as well as animal bones--the remains of students' food.

The thin white tubes that nearly fill one cardboard box are pieces of tobacco pipes, Stubbs says. Mostly English in origin they were used between 1640 and 1760. Archaeologists can date the artifacts according to the hollow pipes, because over time, they were made with smaller and smaller holes.

"it's like somebody dumped their ashtray," he says.

In addition, Stubbs says he found "an extraordinary number of wine bottles." most made of green hand-blown glass.

In two days, Stubbs says, he uncovered more bottles than he had in four years of excavation in the center of the Yard. The number of bottles in the Yard, he says, exceeds what archaeologists find at typical tavern sites.

Because Stubbs has found no kitchen utensils in this trench, he believes the wine was consumed by students who lived in Harvard's old buildings.

"I will assume, and I think fairly safely that a lot of this was probably student-generated," he says.

Harvard records, Stubbs says, show that drunken behavior was frowned upon, and transgressing students were penalized financially.

"From the looks of things, a lot of people were doing a lot of drinking," he says. "A lot of student were fined for drunken behavior."

The artifacts he has found in the Yard are not unusual or unexpected, Stubbs says, but the quantity of material has surprised him. In one nearby area, he filled 10 or 12 cardboard boxes per day.

"Every scoop that comes out has something in it," he says.

"IT SOUNDS sort of odd when you says, I'm digging up Harvard Yard," Stubbs says. But the Yard is, in many ways, a perfect excavation site. The area has been continuously occupied for more than 350 years, and is the only site in North American that has been preserved this well.

The hole for the water main runs alongside the former site of three of the University's earliest buildings all of which contained undergraduate lodgings.

According to records preserved by the Massachusetts Colonial Society, Massachusetts Hall, the oldest Harvard structure still standing and the second oldest college building in the nation, has always housed students. The Second Harvard College, where Harvard Hall now stands, also served as a dormitory after it was built in 1677. A third building, Stoughton College, once stood between the two buildings in front of What is now Johnston Gate.

When workers dug for water pipes in front of Matthews, Stubs says, he hoped of find the foundations of Indian college, a former Harvard building built in 1655.

Once built for the training of young Native Americans, Indian College later served as a publishing house before it was declared decrepit and razed. Its foundation never turned up.

Peabody professor of American Archaeology and Ethnology Stephen Williams, Stubbs' thesis advisor, oversees the Yard excavations.

Most Harvard historians, Williams says, tend to think "we who dig in the ground are some sort of weird antiquarians who love objects."

But archaeologists uncover information that isn't listed in history books or record books, Williams says.

"I have been here at Harvard a long time, and have tried to sensitize the community to the fact that there is information under the ground that tells about Harvard in the past," Williams says.

In 1926, President A. Lawrence Lowell first suggested that the Yard be excavated, Williams says. According to legend. Lowell looked out of the President's office--then in University Hall--and saw people digging a trench near where Widened Library still stands. They had found broken china that dated back to the early 1800s.

Lowell commissioned an artist to make copies of the china, which he sold to interested alumni, Williams says.

Archeologist here, eager to turn up Harvard's underground history, asked the administration to inform them of any utilities they planned to put in the ground.

"We've been fairly successful at getting some response, but not always" Stubbs says.

The administration in general has been supportive to the water main excavation, Stubbs says. Officials informed archaeologists of the excavation months in advance. Harvard provided founding for the dig. And the bid sheet for contractors included provisions that the construction would be monitored archaeologically.

If workers come across a sensitive area like a foundation or a single trash pit, Stubbs can ask them to stop so he can excavate the areas more carefully.

The huge construction equipment makes a large area instantly accessible to Stubbs.

"it's a tremendous opportunity to see what is here," he says.

But the giant scoops of the construction equipment make small detail work difficult, Stabs says. He misses many of the smaller artifacts that could otherwise be sifted form the dirt.

The sheer number of people wow talk through the yard make this site different form others Stubbs has excavated. Digging in the yard Stubbs say "is like working in a fishbowl."

In addition to digging in West Germany, Louisiana and northeastern Mississippi, he participated in Yard excavations in the summer between 1984 and 1947, when archaeologist looked for--and found--the first college building.

"At that time, it was clear that Harvard Yard had a lot of archaeological potential," he says.

Stubbs, who did his dissertation on artifacts from Harvard Yard, lived in Matthews Hall as a first Year student, and was a proctor in the yard and union dorms for eight years. His many years in the Yard, he says, give him a unique perspective on Harvard's history.

WHILE THE YARD covers a wealth of artifacts. Williams warns that archeological excavations often raise more questions than answers. For example he says, it is easy--and appealing--to conclude that the hundred of wine bottles Stubbs has found were all used by students in a party of colossal proportion, it is impossible to tell weather the deposit is the result of one great Commencement bash" or a pile that grew over years.

Laboratory analysis will help provide answers to some of the questions, William's says. Back in the lab, Stubbs will date and inventory the artifacts and reconstruct some of the vessels.

At lot of this material, Stubbs says, is worthy of an exhibition. Already, the Harvard Union has a second--floor display of some Harvard artifacts. Stubbs' new finds would complement that collection, he says, or may wind up in a Peabody Museum gallery.

Stubbs would also like to write a book, he says, documenting the archeological history of Harvard yard. With the exception of two digs, Stubbs has been present at every Yard excavation.

But for the coming weeks, as construction workers refill this trench and dig another deep hole from Matthews to University Hall, Stubbs will be working outside. he will be sifting through dirt, collection odd fragments of galls and clay and, perhaps, imagining the last great Yard party.