Aged nine Laurence was taken to admire the capital’s doomed gas holders and cooling towers. He spent the next 40 years exploring corners of the earth as far away from London as possible. A rekindled enthusiasm for the city, and particularly its most ingenious or scientific past inhabitants, encouraged him to write and to offer guided tours, and he has set quiz rounds for the British Library. When a hi-tech engineering career threatened to force him from London he rebelled and joined the ranks of the underemployed. He is a heritage volunteer who helped lead the first horse drawn barge in 60 years along the Regent’s Canal and who has handled the great experimental philosopher Michael Faraday’s shoe brushes.