Ocean currents produced by evaporation and precipitation

At the end of his paper on the long period tides Hough* discussed the effects of precipitation and evaporation in reference to steady currents in the ocean. He assumed that the ocean covered the whole globe and that the precipitation and evaporation were functions of the latitude only. His work showed that no steady motions exist in this case. The present paper examines the case of an ocean bounded by shores extending from pole to pole along meridians, for which the evaporation and precipitation are also functions of the longitude. The results show that for a probable system of distribution of evaporation and precipitation steady currents do exist and are of the kind actually observed in the great oceans.