And even if it hasn't happened to them or someone they know, it's a rare genealogist whose search has not been affected by the fire that destroyed so much of the 1890 census or the 1973 fire that took out roughly 80 percent of 20th century military personnel files held in St. Louis. But far more dangerous than these major events that capture our attention is the subtle deterioration that is happening every day. Wind and water erode. Dust and dirt cover things. Sun dries out materials.
Gravity pulls matter down and breaks it.
Leather dries and cracks. Worms and rodents feed on paper, glue, cloth and leather. Pencil lines smear and rub off. Book bindings crack and break. Staples and paper clips rust.