=Overseas Repair Section No. 1.= During the latter part of November, 1917, Overseas Repair Section No. 1, under the command of Captain Mayo-Smith, Sanitary Corps, with four other officers and 130 men, arrived in France. Since mask development and manufacture in the United States was still under the Medical Department, this mask repair section was organized as a part of the Sanitary Corps. As there were at that time no masks to be repaired and no laboratory equipment or buildings for that purpose on hand and none likely to be for months to come, Captain Mayo-Smith was assigned to duty under Colonel Crawford, Chief Gas Officer with the Line of Communication, in Paris. A site for a mask repair plant was located at Châteauroux, and a site for a gas depot at Gievres was investigated. Inasmuch as there was at that time greater need for men to learn the handling of poisonous gases than to repair masks, some 40 or 50 of the company were put in gas shell filling plants at Aubervilliers and Vincennes in the suburbs of Paris, while later still others were assigned to Pont de Claix near Grenoble. The remainder of the company were used in the Gas Depot at Gievres and in the office in Paris. It was not until the latter part of June, 1918, that the mask repair plant began operations. In the meantime these men did very valuable work in shell filling and in learning the manufacture of gases. Several of them were sent to the United States, some of them remaining throughout the war to aid in gas manufacture and in shell filling. =Construction Division, Gas Service.= The Construction Division under Colonel Crawford in Paris made complete plans for phosgene manufacturing plants, for shell filling plants and for the Mask Repair Plant. These plans included a complete layout of the work for all persons to be employed in the plants. During this same time a very careful study of the possibilities for manufacturing gas for filling shell in France was made.