THE Department of Aeronautics at the Imperial College of Science and Technology is the largest activity of its kind in the British Empire. The announcement of the appointment of Mr. A. A. Hall as the new head, to succeed Prof. Leonard Bairstow as Zaharoff professor of aviation, is therefore of great interest. Mr. A. A. Hall will be one of the youngest professors in the country. If the course of the War makes it possible for him to take up his new appointment in October 1945 he will then be just over thirty years of age. He comes from Liverpool. Educated at the Alsop High School, Liverpool, and at Clare College, Cambridge, he obtained first-class honours in the Mechanical Sciences Tripos of 1934, wibh distinction in aeronautics, in thermodynamics, in applied mechanics and in the theory of structures. He was awarded the Rex Moir prize in engineering, the John Bernard Seely prize in aeronautics, the Ricardo prize in thermodynamics, and the Robins prize of Clare College. After a short period at the Royal Aircraft Establishment, he returned to Cambridge with an Armourers and Braziers' research fellowship to pursue aerodynamic research under Sir Melvill Jones and Sir Geoffrey Taylor. The work he did then, on the turbulence in a free stream and on the laminar and turbulent boundary layer, was an outstanding contribution to the subject. He joined the staff of the Royal Aircraft Establishment in 1938 and his activities there have covered a wide field-aerodynamics, wind tunnel design, and jet propulsion, followed since the outbreak of war by investigations on night interception of aircraft and on many scientific and engineering problems in the field of aircraft armament. In all he has shown high qualities of original thought and of leadership-the best augury for his future in a most responsible position.