Measurements have been made of the anisotropy of neutron slowing down in Al-H2O plate lattices. The moments of the slowing down distribution from fission to 1.46 eV were determined in the two characteristic directions at two volume ratios using the point-source, point-detector method. For the 1:1 case, with an Al plate thickness of 0.25 in., the ages parallel and perpendicular to the plates were 65.4 ± 0.8 and 60.8 ± 0.8 cm2, respectively, giving an anisotropy of 1.076 ± 0.02. In the 2:1 (A1:H2O) case, with an Al thickness of 0.50 in., the corresponding values are 100.3 ± 1.5 and 92.5 ± 1.3 cm2, giving an anisotropy of 1.085 ± 0.02. The higher moments were characterized by higher anisotropics.