A photograph entitled 'Demonstrating a Crile head tractor', taken in October 1937 by Saidman for the Daily Herald. This device - shown here at a medical exhibition at London's Horticultural Hall - was invented by the American surgeon, Dr. George Crile (1864-1943).

A photograph entitled 'Demonstrating a Crile head tractor', taken in October 1937 by Saidman for the Daily Herald.

This device, shown here at a medical exhibition at London's Horticultural Hall, was invented by the American surgeon, Dr George Crile (1864-1943).

Two Saidman brothers, Reuben and Barnet, worked as staff photographers for the Daily Herald. Their photographs are simply stamped 'Saidman' on the reverse, making it difficult to tell which of the brothers took the photograph.