The author began by stating, that during a calm, when the rain-drop was under the influence of the centripetal force only, the form and position of the rain-gauge were unimportant. The case, however, was widely different when the drop was likewise influenced by wind, for then any object raised above the surface, such as a rain-gauge projecting three or four feet from the ground, occasioned deflections and eddies, whereby the regular fall of the rain into the collector was prevented. The Author then recommended, that in all cases the gauge should be placed on the ground, with its mouth on a level with a regularly trimmed grass plot, so as to prevent eddies and evaporation.