Equipment was tested in Wisconsin in 1947-48. The method of application at 30 to 40 lbs. pressure and 15 to 30 gal./acre appeared to be secondary to dosage per acre of 1 lb. technical DDT or chlordan, or 1.5 lbs. technital chlorinated camphene. Emulsions appeared to lose their residual effectiveness more quickly than wettable-powder sprays. Most machines tested could be improved by pumps of increased capacity, especially if used for wettable powders. The use of an emulsion is perphaps more desirable in sprays with limited capacity pumps.