1. Egerton Ch 7427 Reference (shelfmark): Egerton Ch 7427 Title: Scope & Content: John Thompson, merchant, of London: Signet Warrant for inventor's patent to, for a corn-grinding machine: 1717. Inventions: Signet Warrants for patents for inventions: 1717-1725. Collection Area: Western Manuscripts Languages: English Date Range: 1717-1725 Extent: 1 item