Wherever on his worldwide playground Dr. Lorin Lindley Hawes may at present be found, he serves still and forever as an inspiration to those of us who have always wanted to stop being serious and start being rich.

Hawes used to be an American atomic scientist, but he got sick of that and fled to Australia, where he started fooling around with boomerangs. The more he fooled with them the more they intrigued him, because boomerangs -- as this Saturday's annual Smithsonian Boomerang Tournament will show once again -- are a mystery that defies science and drives basement tinkers right around the bend.

Hawes spent years studying boomerangs. He didn't learn a whole lot more than other good men who have broken their heads and hearts trying to understand them, but he did develop a simple plywood boomerang that sells like Hotcakes on Sunday morning. Now, while still in the full flower of his manhood, he ranges the world and sports him as he may.

A zillion of Hawes' devices, along with as many others crafted in home workshops, will be whirling above the West Potomac Park Polo Field Saturday while Washington Boomarangmeister Ben Ruhe tries to keep track of what's going on. Registration commences at 1. The rain date is listed as June 21, but "it will come a flood or a hurricane before we call it off", Ruhe said. "I do not intend to go through all this again."

Ruhe, who got into boomeranging while working as a jackeroo on an Australian ranch, started the Smithsonian affair 12 years ago as a lark, something to enliven the Mall on a slow weekend, but the thing took wing and now draws a host of participants and so many spectators that it had to be moved to the vast field between Independence Avenue and Ohio drove, near the Lincoln Memorial. Contestants come from as far away as Canada, Belgium and, ah, Australia; dignitaries, appear; and Rukhe, as always, worries that the tournament might grow too formal.

"Never happens, though," he said. "It's an iherently unsolemn pastime. And the tournament is always free and open to anyone nine and older -- we wish we could include younger children but a boomerang is, after all, a missile, and it just doesn't work out -- and they can bring any sort of lightweight, two-bladed boomerand they like."

Two-bladed boomerangs are specified because "returning airfoils" can be made with almost any number of wings, and the silliness has to stop somewhere. The rules are broad enough to include devices shaped like the letters A, c, g, i, J, L, N, S, U, V and Z, all of which have been successfully flown.

Among the boomerangs unacceptable for the competition are the hard plastic ones sold by manufacturers. "They're exact copies of successful wooden boomerangs, but they don't work and they're dangerous," Ruhe said. "I for one am happy that so far only wood has worked well in boomerangs. They are individual, unpredictable things, and only plastic just dosen't seem to have that magic quality."

Another thing that keeps boomeranging jolly is a key rule, universally adopted from the Mudgeeraba Creek Emu Racing and Boomerang Throwing Association of Mudgeeraba, Queensland: The decisions of the judges are final unless shouted down by a really overwhelming majority of the crowd present .

Individual events include juggling, doubling (keeping one pair of boomerangs aloft at all times), duration of flight, accuracy of return and successive catches. The team events are fascinating to watch but not easily described.

There also will be exibitions by people who do things with boomerangs that are not to believed, even after they do them two or three times in a row.

World distance champion Al Gesrhards will be there, which is enough reason by itself to come out. Gerhards, a dental technician who is as friendly as he is large, which is very, throws so hard that Ruhe twice has seen Gerhards fracture epoxy-laminated boomerangs on launch. When Gerhards throws, his boomerang fades out of sight while he ties his shoes, or pokes around in Big Al's Boomerang Bag, or joins whatever conversation may be going on around him. By and by he reaches up and plucks it from the sky.

gerhard's record, which is 123 yards with a complete return, is in dispute.

All boomerang records are in dispute, which is part of the charm of the thing. Somebody is working on a radar device to make distance precise and indisputible, but meanwhile Gerhards just smiles, a boomerang nestled in his vast palm, accepting all challanges.

The secret of Gerhards' phenomenal long-distance throwing is not strength but cunning. According to a recent paper by Scottish investigator M.J. Hanson in The School Science Review . "Each boomerang has a built-in orbit diameter," Hanson writes. "if it is launched with more vigour, then it simply gets round the same orbit quicker and may start a second orbit."

Gerhards experience seems to support this; for all his mighty arm he cannot make a boomerang soar like a bird if it has the soul of a manhole cover. While giving a throwing clinic last week he discussed the relative merits of shagbark hickory and pignut hickory, and spoke of dihedrals, and centers of mass, and moments of inertia and so forth, but then he pulled out a boomerang he said was just like another one he made at the same time, except that it wouldn't fly for beans. "They were made to be identical, they seemed to be identical, but it took me two years of fooling with this one to make it go."

Gerhards will tell you anything, which bothers the heck out of Ruhe, because the Pennsylvanian is the heavy of the U.S. team that will tour Australia this November, if Ruhe can find the sponsers necessary to get them Down Under. "i keep telling Al to keep quiet, and stop passing his boomerangs around," Ruhe said. "There are other big guys around, and I have this fear that a giant Aussie secret agent will get hold of one and throw it around the moon."