The collection curves of both single and multi-wind systems resemble sine curves; these curves were completed by interpolation. Bias properties of both systems can be described by certain parameters. For the HOW platform, a single-wind system, its bias ratios varied over a narrow range of 1.4 to 1.8 where the ground factor is close to unity. The platform-ground data of the HOW station is too limited to permit extrapolations to other single-wind systems. In the case of the YAG's, the bias ratios ranged from 1.8 to 20 and the bias fraction from 0.16 to 0.97. Bias vector summation showed that the YAG-40-B, YAG-39-A and YAG-39-D experienced single-wind bias. The sampling bias of the LST and YFNB's could not be completely defined because of the complications caused by the ship structures. Their approximate bias ratios varied from 1.3 to 3.6. The determination of equivalent ground values of shipboard collections was not possible because of the undefined platform-ground relationship in the multi-wind cases and the lack of bias ratio-ground factor data in the single-wind cases. Approved by: E. R. TOMPKINS Head, Chemical Technology Division For the Scientific Director 31