A product of Power Specialities Ltd. of Maidenhead (later Slough), the "Rotoscythe" was the world's first rotary lawnmower, being introduced in 1933 from a design by David Cockburn. Cutting was by a rotary impeller with cutting discs, and the cut grass was driven into the rear-mounted grass box. Pre-war "Rotoscythes" were available with 14, 16, and 20 inch cut, as well a special long grass pram-wheeled 18 inch version. Post-war the company produced the "Rotoscythe 16", as a more streamlined version of its pre-war machine. This had Power Specialities' own 120cc engine and sold for £38.15.0d (plus P.T.) in 1949. After 1952 when Power Specialities Ltd. had been acquired by J.E. Shay, the "Rotoscythe 16" and its variants, the "Windsor" and the "Eton", continued in production and the basic design was continued by Wolseley-Webb into the 1970s.