Martin adopted abstraction in the late 1940s, constructing his first mobiles in 1951. In 1953, he established his most characteristic form, the Screw Mobiles. The geometry resulting in spiral structures occurs naturally in shells. It was discussed in D’Arcy Wentworth Thompson’s influential book On Growth and Form, which Martin is known to have consulted. The group of British artists known as the Constructionists rejected mimetic art in favour of new (predominantly geometrical) forms, materials and techniques. Yet, naturally occurring sequences could still be the sources for such works.