tears, punctures, or other defects. See that it is properly connected to the canister nozzle and to the angle tube and that the adhesive tape over the binding wires is present and in good condition.

FOUR. Examine the outlet valve for tears and pinholes by distending the rubber between the fingers (Fig. 130-4). Look especially for pinholes,

Fto. 130.—Matk inspection by the number» (ConlinucJ*. (4) Inapc^tinir the nutlet valve and guard nt the commnnd FOUR. In»pectin« the fmepiece at the command FIVE. («) Inspecting the head hnrne«» at the command SIX.

just below where the outlet valve is joined to angle tube, and for tears around valve opening. See that valve has no dirt or sand in it and that it is pro|>crly connected to the angle tul»e. See that the binding wire is projMTly taped. .See that out let-valve guard is not loose.

FIVE. Examine outside of facepieee for tears or other damage t<> stockinette. See that angle tube is properly connected to faeepiive, with rubber l»nn<l surrounding the binding. See that the fabric has not torn or pulled loose around the eyepiece frames. Examine the chin seam and see that ii is in good condition and properly taped inside and outside. Examine the inside of the faccpiece for pinholes (Fig. 130-5). See that the deflector is in good condition, properly connected to the angle tube, anrl properly cemented to the sides of the facepieee. Test the entire facepieee fabric for softness and pliability.

SIX. Examine the head harness (Fig. 130-6). Make sure that it is complete, that all its parts are properly attached, and that they are in a serviceable condition.

SEVEN. All men with defective masks step forward one pace, others replace mask in the carrier, taking care to replace canister and facepieee in projn.T position (Fig. 131).

Cake ok the Mark

Thi' importance of care of the mask, guarding it es|>ecia!ly against moisture and rough handling, should be impressed upon troofxs. They should l>e made to understand the causes of deterioration of gas masks and realize that a defective mask affords no protection.

Excessive and prolonged moisture causes general deterioration of a gas mask finally rendering it useless altogether. Moisture in the canister materially reduces the adsorptive 1 >ower of charcoal and is likely to result in caking with the opening up of large air passages through which the gas will freely flow owing to lack of sufficient contact with the alisorbents.

Moisture causes rotting of the stockinette and deterioration of the rublxr itself. The corrugated tube, flutter valve, and head harness are likewise affected. When the facepieee of a mask becomes wet and the mask is put away without careful drying the rubber tends to crease or take a permanent set so that it will no longer fit closely to the face. Other effects of moisture .are deterioration of the adhesive tape, rusting of binder wires, and separation and mildew of the eyepiece, i n.. 131.—Kcjilnritig the If a mask has been used in the rain or has f:,,,,",'r"Jirripr- otherwise become wet, it should Ik» slowly dried m a warm room. In no case should it be placed on a stove or near a fire ;is the rubber will be damaged.

Kulibrr parts of the mask gradually deteriorate with aye though the use of aniioxidents in the manufacture of rubln-r tends to prolong its life. If exposed to sunlight or heat the deterioration is greatly accelerated. Oil is also a cause of deterioration and oil from the hands and lace arc likely to accumulate on masks in service use.

Masks in storage should be kept in a cool dry place away from contact with sunlight, oils, corrosive liquids, or solvents. Packing in airtight

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