Strapped for money, archivists around the country are looking to private partners for help. Google has donated $3 million to help start an effort led by the Library of Congress that will digitize and share materials around the globe, and has also provided technical resources for digitizing various printed materials at the library. Google, on its own, is digitizing books at the Library of Congress, which has its hands full with other items. And a number of other companies and foundations, including Reuters, I.B.M. and the Andrew W. Mellon Foundation, have financed digitization projects around the world.

Image Despite ambitious and continuing digitization efforts at the Library of Congress, only about 10 percent of its vast collection is expected to be digitized anytime soon. Credit... Doug Mills/The New York Times

Even with outside help, experts say, entire swaths of political and cultural history are in danger of being forgotten by new generations of amateur researchers and serious scholars.

Consider the Library of Congress archive of one million photo prints from The New York World-Telegram & Sun; only 5,407 have been digitized. Of the 1.2 million images from U.S. News and World Report, the library has digitized only 366. Its collection of five million images from Look magazine, spanning the period from 1937 to 1971, creates what Jeremy E. Adamson, director of collections and services at the library, calls "a fascinating portrait of America through photo stories on social and political subjects, personalities, food, fashion and sports." Yet only 313 of those images have been digitized.

"It's a crying shame," Mr. Adamson said, "as today's public is acutely visually literate and comfortable with pictures as a means to understand the past and experience for themselves the direct look and feel of history."

The reason for not digitizing these collections? "Not enough money," Mr. Adamson said.

THE decision to put off digitizing a significant collection is seldom easy, archivists at the Library of Congress say. Plans to digitize The National Intelligencer, a newspaper published in Washington during much of the 19th century and filled with Colonial script not easily recognized by digitizing equipment, eventually had to be put on hold because of the high expense.

"If researchers conclude that the only valuable records they need are those that are online they will be missing major parts of the story," said James J. Hastings, director of access programs at the National Archives. "And in some cases they will miss the story altogether."

Maritime buffs, for example, hoping to use the Internet to piece together the story of the Silenus, one of the finest ships ever built in North America, will find a spotty narrative. The papers of its captain, Joseph King, who lived a brief but adventurous life, from 1782 to 1806, can be found courtesy of the Mellon Foundation, in a digitized archive from the Mystic Seaport's collection. Researchers will see how much Captain King paid for "1 potte lijn oli" in 1803, when the ship was in the Netherlands.