IN the Askania Review, the journal of the Askania-Werke A.G. of Berlin, the well-known makers of instruments, there is an interesting and instructive article on ‘The Divisions of the Circle’. It is pointed out that all topographic services of the Reich are adopting the division of the circle into 400 grades instead of 360 degrees. A history of the adoption of these units is given. The Babylonians knew that the sun completes the zodiac once within 360 days approximately, so that 1° is approximately the sun's daily travel. The adoption of 360° is advantageous inasmuch as the figure is readily divisible by 2, 3, 4, 5, 6, 8, 10, 12, etc. The resulting arcs of the circle or the angles of 180°, 120°, 90°, 72°, 60°, 45°, 36°, 30°, etc., are of great importance in connexion with regular diagrams as well as in technics. Since the absolute angular unit defines the angle by the ratio of the arc length to the radius, it has no ‘physical’ dimensions. In Germany, therefore, it is not given any special name. In other Anglo-Saxon countries it is usually called the ‘radian’.