Clocks: faces (top), and mechanisms (below) of a Ferguson (right), and a Smeaton-Franklin clock (left). Coloured engraving… https://www.rawpixel.com/image/13953744/image-cartoon-faces-circleFree Image from public domain licenseClocks: a Smeaton-Franklin clock (top), and a Ferguson clock (below). Engraving by J. Taylor. https://www.rawpixel.com/image/14008564/image-paper-pattern-circleFree Image from public domain licenseJames Ferguson. Line engraving by T. Cook, 1778, after J. Townsend. https://www.rawpixel.com/image/14009586/james-ferguson-line-engraving-cook-1778-after-townsendFree Image from public domain licenseJames Ferguson. Stipple engraving by T. Wright after J. Northcote. https://www.rawpixel.com/image/14017520/james-ferguson-stipple-engraving-wright-after-northcoteFree Image from public domain licenseJames Ferguson. Mezzotint by R. Stewart, 1776, after J. Townsend. https://www.rawpixel.com/image/14008639/james-ferguson-mezzotint-stewart-1776-after-townsendFree Image from public domain licenseJames Ferguson. Mezzotint by F. Haward, 1776, after J. Northcote. https://www.rawpixel.com/image/13992639/james-ferguson-mezzotint-haward-1776-after-northcoteFree Image from public domain license