[1][2][3] Born on 12 June 1785 into the Quaker family of a grocer in Hull, Hornor (sometimes spelled Horner) learned surveying and engineering from his brother-in-law.
He lived in Kentish Town, Chancery Lane, and then Church Court, Inner Temple, whence he undertook valuations as well as surveys and levelling of canals and drains.
He was successful and became wealthy producing bound portfolio volumes of plans, panoramas, watercolour paintings, all linked by exquisite copperplate handwritten accounts of tours in the area, for at least nine wealthy families with whom he appears to have mixed as an equal; at least one still bears the price, 500 guineas.
Initial plans to sell panoramic views came to nothing but an elaborate scheme to create a 360 degree panorama on the inside of a dome of the Colosseum,[9] specially built in Regents Park (and resembling the Roman Pantheon rather than the Colosseum), came to fruition but at such expense that his principal backer, Rowland Stephenson MP, had to flee to America in 1828, soon followed by Hornor.
[10] The Colosseum included a device to take "the visitor who pays an extra price"[11] to a suitably elevated viewpoint: Hornor had designed the first passenger lift in England.