Where from 4 to ten feet of head can be made available or where maximum efficiency is called for, it is doubtful if any aeration device can compete with the spray nozzle. This is believed to give a better dispersion or subdivision of the water that can be obtained by any other method. Moreover, the dispersion of all the water into small drops creates momentarily the maximum practical surface area of water in contact with air which facilitates adsorption of oxygen and expulsion of dissolved gases. Any degree of fineness may be obtained by a spray nozzle, varying from atomization up to coarse drops, but for practical reason only the large size nozzles having an orifice of one inch diameter and larger are used. The smaller nozzles have a tendency to clog and have a high loss of head. Spray nozzles require a minmum of head of about 4 feet, but much better results are obtained with some waters from higher operating heads. Possible damage to adjacent property from wind carriage of water has to be considered in connection with spray aeration.