The geological factors that are significant in the evaluation of excavation characteristics of earth and rock materials are descriptionbed and a guide to the assessment of rippability by tractor mounted rippers is provided.
Effective water pollution control embraces more than just supervision over the purification of polluted water. Pollution abatement in the fullest sense implies more efficient use of natural resources. The industries of South Africa are descriptionbed as they occur in certain defined regions. Present methods of pollution abatement are discussed as well as trends toward the better utilization of raw materials which could result in higher production coupled with less pollution. Conversion of wastes to useful products and research work in this connection are mentioned.