A long line source has been simulated by placing a horn terminating in a slot8×14in.. between two large, rigid plane surfaces 8 inches apart. The resulting cylindrical sound field has been used for measurements of acoustic radiation forces. The force exerted on rigid spherical obstacles of up to 3 cm radius has been measured at distances within 10 cm of the source of the field. Forces of attraction have been found; their magnitude as a function of frequency, size of spherical obstacle and distance from the source is in agreement with theory [T. F. W. Embleton, J. Acoust. Soc. Am.28, 155(A) (1956) and Can. J. Phys.34, 276 (1956)]. This apparatus overcomes the difficulty of eliminating spherical waves from the sound field encountered in previous experiments with a short line source.