Spotlights a treasured collection of objects from Carnegie Mellon's special collections to mark the reopening of the Posner Center. Rare Books & Ancestral Machines is a portable guide to the Posner Center--home to Carnegie Mellon University's special collections and the university's repository for rare books, manuscripts, and early technologies. Part museum and part laboratory for the humanities, the Posner Center is Carnegie Mellon's destination for discovery, research, and hands-on engagement with the past. Published to mark the reopening of the Center in fall 2025 after an extensive renovation, this richly illustrated handbook features nearly one hundred objects from the collection alongside eight interpretive essays. Designed to reflect the layout and logic of the Posner Center itself, the book blends item descriptions, illustrations, and thematic reflections in a compact, visually engaging format. It celebrates both the history and the future of special collections at Carnegie Mellon.