If you cross the P Street Bridge into Georgetown and turn left, past the P Street Beach and head for the tennis courts on O Street, you come to a little grove, or meadow with a few trees, that adjoins the Rock Creek expressway. This place is sacred to (but illegal for) romping dogs.

"They come down and give everybody a ticket," said a fellow whose dog was present one recent afternoon in the daily gathering of mutts. "Not very often. They don't hassle us."

About 3 p.m. the dogs begin drifting in or, more often come charging in with full-throated cries dragging their master behind them.

"NO", roared an angry fellow at his dog, who had escaped from him and bounded across the street into the park.

"Just for that, you're not getting off the lead this afternoon," the man said. The dog glared but said nothing.

Another dog on his lead among the free spirits bouncing about like young sheep was Zacchariah, a stately Afghan hound who looked somewhat like Hamlet's father.

As all the others races about, sniffing all things sniffable and trying things out ("Oh, why does he DO that? I don't know what's got in him," said a woman of her pooch) the big Afghan lay like an upholstered sphinx on a picnic table, his owner holding the lead.

Zacchariah looked around from time to time, possibly to see if by any chance Happy Hour had arrived. His fault (as some might call it) is that he chases cats, which in Georgetown are thicker than dandelions.

Thus he never gets to run. He seemed to enjoy watching the young folks have a good time, though.

Most of the dogs have owners who show up every day, or several times a week anyway. Nancy Kissinger is often there with her Tyler.

"TYLER," she screams from time to time if she is there and if Tyler requires reproof.

It is poor form, one gathered, to look at anything or discuss anything much except the dogs roaring around the field or chasing sticks on dodging trees.

Since this no-man's land dogwise, the dogs do not feel obliged to show how tough and macho they are. On their home turf, a dog is expected to growl a good bit or break down the door to chase the postman two minutes after the postman has left.

But here - these are bright fields of peace and substantial waggery. There are yelps, barely distinguishable from the sounds of children's tag on a summer day.

It is usually after a good many visits that one exchanges names with other dog-toters.

It is, after all, public land and not many people wish to strike up great conversation with strangers in such places.

But the dogs, among whom crime and secret motives are rare, stand on no ceremony. New dogs never think, Alas, I am only a Labrador and he is a real basset. Not at all - they charge right up with tail wagging, and after a few false starts, common to all living beasts, they are almost immediately bounding about in consort and in utter concord.

There is a foot path at the edge of all this romping. Occassionally a dog owner with a very small breed (a Maltese, a Brussels griffon or an undersized Lhasa, for examples) may pass by, swooping up the animal in his arms. The other dogs usually do not even look that way, but the small dog being held is usually very interested to know why the hell he cannot go over there.

Soon it is time for tea, or time to think of supper.

People wander off home, and it is inspiring to see how keen their dogs are to go along with them. They do not plead to stay one more half-hour. They go, obedient and enthusiastic. Right are they called man's best friend.

Some are mongrels, some are purebred, and some you just shake your head. The owner see things nobody else does. You may see some very sorry looking dogs. But nobody present in the park thinks his is one of them.

But now the grove is empty. Chow time throughout the world. "Oh, Evening Star," as Cleopatra's handmaid once cried to her, and "Peace, peace" as Cleopatra said in response. It would have been better for her if he had held, just then, a mutt in her arms.

But too much reflection is bad for dogs. Tomorrow to fresh fleas and woodticks new.