... and neighbouring 6 WHITEHEAD ON DIRECTIONATLRAFFIC SURVEYS counties. The conditions, however, are probably typical of rural areas in Great Britain where traffic intensities seldom rise above 250 vehicles per hour in one direction. For the more intense traffic in towns, a different technique may be necessary...

... FLEMING A N D BLLEN ON MODERNTHEORY SOUND AND UNITSOF MEASUREMENT. Intensity: the decibel.-The sensation of sound is produced by small alternating pressure-variations in the air, which are propagated as a wave motion with a velocity of about 1,130 feet per second. The frequency of alternation may range...