I already know one relic:
Smokepowder

The Hall has held many marvels over the years. Currently on display are many small devices and a few large pieces. Many of the small devices seem to be locks or strongboxes so devised as to look like something else, from goblets to statues to chairs. The larger items include a mechanical scribe, a steam dragon, a pump of Gond, an everlight, a fan chair, and a farseer.
Unless one has been to the Hall, some or all of these items are undoubtedly unfamiliar, so I will attempt to describe them and their functions briefly A mechanical scribe is a handset type printing press. A steam dragon is a steam engine with fittings that render it capable of moving large objects along a continuous path by means of pulleys, of pumping water, of operating a lift up a cliff or wall by means of a continuous rope, of rowing a barge, and so on. A pump of Gond is a muscle-powered pump, worked by pedaling a flywheel, for use in farm irrigation and in filling bilges and reservoirs. An everlight is a system of self-filling oil lamps fed from a central oil tank. A fan chair is an adjustable reclining chair that can be rocked, operating a fan to cool the sitter. And, finally, a farseer is a seeing glass with a series of tinted and graduated glass lenses that enable it to be used for viewing tiny things up close, viewing sights as far away as the horizon, or focusing the heat of the sun so as to ignite or melt things.