1. Jr. Research Engr., Hydrological Research Unit, Dept. of Civ. Engrg., Univ. of the Witwatersrand, Johannesburg, South Africa; formerly Byllesby Fellow in Civ. Engrg., Lehigh Univ., Bethlehem, Pa.
2. Dir., Hydr. and Sanitary Engrg. Div., Fritz Engrg. Lab., Lehigh Univ., Bethlehem, Pa.