Almost half the patents issued last year by the U.S. Patent and Trademark Office went to foreigners -- a far cry from the mere 11% that foreigners won a quartermere 11% that foreigners won a quarter-century ago. In the same 25 years, the U.S. balance of trade has shifted from $5.6 billion in our favor to close to $150 billion on theirs. In case there's some connection between the trends, at least one institution in Washington, D.C. -- a private group called The United States Patent Model Foundation (USPMF) -- is doing something about it. Not by shrinking the trade deficit, mind you, but by prodding us to invent more products.

And it's not the country's Ph.D.s they're hoping to inspire, but schoolchildren, all 31 million of whom have been invited to participate in USPMF'S "Invent America!" campaign to rekindle the flame of commercial creation. The idea, says USPMF vice-chairman J. Morgan Greene, "is to put us back in the competitive running with the Japanese, who have had their Institute of Invention in operation since 1941 while we sat back and did nothing." Japan receives more than half a million patent applications annually, he frets, while the United States gets only about 130,000.

In pilot programs, schoolchildren have already dreamed up such potentially marketable gizmos as "a tall hanger for short people," a lock that lights up at night when approached by a key, a floating jigsaw puzzle for swimming pools, and an umbrella with a flashlight in its handle. "They may not be electronic geniuses," concedes Greene realistically, "but in 10 years, they could develop their own businesses." Some are indeed headed in that direction: Wendy Johnecheck of Petoskey, Mich., for one, receives royalties from the domestic manufacturer of a centerpole jumprope system she devised in the fifth grade.

Next month, the end of the program's first year, awards will be given to the inventions voted best by a panel of grownups, including the U.S. patent commissioner, a judge, and a banker. Then the typically native curiosities (the inventions, not the panel) will be put on display at the Smithsonian Institution.

At that, it will be USPMF's second collection to make it to those quaint halls. The first was a roundup of the small-scale models that until 1870 had to accompany patent applications. After the government discontinued the requirement -- apocryphally, perhaps, on the grounds that everything that could be invented had been -- a distressingly large fraction of the 175,000 constructions didn't survive banishment from federal safekeeping. But with the backing of a hoped-for $20 million in corporate contributions, USPMF is bringing the survivors together again. Along with standard examples of Yankee electronic ingenuity gathered from Morse, Edison, and Bell is the "New and Improved Manner of Buoying Vessels Over Shoals," patented May 22, 1849, by one Abraham Lincoln, of not only shoalless but waterless Springfield, Ill, No genius, obviously, but at least the youth showed enterprise.