The 8 MeV linear accelerator at the MRC Cyclotron Unit, Hammersmith Hospital, London.

This machine was the first linear accelerator designed for medical use and the first to be installed in a hospital. The first patient was treated in 1953 and the last in 1969. During this period the machine was used for research during the evenings and latterly it was available for research all day long. It was switched off for the last time in February 1984. In addition to the X-ray beam, electrons were used for treatment and for research, where the high dose rate and large field size were particularly useful. An account is given of some of the highlights of the clinical and research programmes.