. provided on Eniwetok and Parry Islands for limited fire pro- tection service, The temporary character and small size of other installations did not justify installing elaborate high pressure fire protection facilities. The salt water elevated storage consisted of storage in a bolted steel tank (procured from Navy surplus supplies at Pearl Harbor) mounted on a wood tower of sufficient height to maintain desired operating pressure upon the salt water distribution system, Fifty foot towers were used on Eniwetok and Parry Islands and 30 foot towers at all other locations. Wood towers resisted the climate and could be erected by semiskilled workmen, The elevated tank rode or "floated" upon the system and thus equalized static pressure throughout the distribution system, This tank simultaneously acted as a governor which permitted the system to operate at all times under the wide range of conditions caused by the summation of drafts upon the system as total output, and the constant rate or rates established by the raw water pumping units acting singly or in combination as total input, Tank sizes throughout the Proving Ground were standardized, where feasible, to take advantage of surplus Navy stocks at Pearl Harbor, The distillation equipment consisted of a battery of compres-— sion type stills on each inhabited island for conversion of salt water to fresh or potable water. Each battery of distillation units was supplied from the salt water distribution system, This connection constituted the largest single draft upon that system. The manufactured product of these units (distilled water) was then transferred to surface storage tanks. For flexibility of design and installation, new dis- tillation units were standardized in capacities, Two sizes, 85 gph and 600 gph, were specified throughout the Proving Ground installations. The sizes specified were chosen because the 85 gph units were readily available for procurement and the 600 gph units were the largest practical size for installation at Eniwetok, Larger units were much more complex in operation, and would introduce unnecessary problema in transportation, operation, and maintenance. In order to make available a sufficient supply of fresh water for construction forces, rapid procurement of the 85 gph units was essential in order to supplement the salvaged stills located on the Atoll and rehabilitated by H&N personnel. It might be noted at this point that the salvaged stills mentioned were later used as auxiliary units during peak population periods. Chlorination of distilled water was provided to further safe- guard potable water from contamination. Small hypochlorinators which permit the use of solutions mixed on the job for supplying the chlorine for disinfection were used to inject the chlorine solution into the fresh water system at a point in the 5-187