I'm going nuts trying to find a copy I own of a short story. I think the author was D. Brin, Alan Steele or Harry Turtledove. Its about a post-apocalyptic society that mines the ruins of our world as it claws its way back. It's told in vignettes covering various time periods, with the first about a bandit/warlord re-discovering "advance" firearms, the second is about his descendant bringing WW1 style planes back, etc. Each vignette features a scientist type, with the role expanding until a formal "Bureau of Tech Reclamation" evolves. The final segment features the Starship Claude. Sad that I can recall so many details-but can't remember the author or title.