The National Geographic Society, chronicler and patron of some of the world's greatest adventures, celebrated its 100th birthday by donating $20 million to help overcome the ignorance of American children about the planet they live on. "Our kids don't know where they are. And if you don't know where you are, you're nowhere," said Gilbert M. Grosvenor, president of the society and great-great-grandson of its founder. The money will go into a new foundation, and the society promised to add $20 million more if outsiders contribute an equal amount. A Geography Education Project started by the society in 1985 has been spending $4 million a year. Creation of the National Geographic Society Education Foundation will give that program a permanent base. The foundation's primary emphasis will be on teacher training. It was Jan. 13, 1888, that 33 geographers, explorers and armchair adventurers gathered in the Cosmos Club near the White House to organize "a society for the increase and diffusion of geographical knowledge."