The inventive Edgeworth, an uncategorisable radical thinker and father to 22 children, is particularly known for his enquiring, child-centred ideas about education. Darwin, Wedgwood, Boulton, Watt, Keir and Small were all Lunar Society friends, the first two especially close. Johnson published his best-known work, co-written with his daughter Maria. His translator Pictet drew him to France, where he met Montgolfier, and where he and his lifelong friend Day visited their hero Rousseau. He was introduced by his friend Banks to Hunter, Cook, Solander, Maskelyne and Smeaton, and constructed an early and unsuccessful telegraph across Ireland with Beaufort.