German Mask

The early type of German mask probably served as the model for the French A. R. S. mask. The facepiece was made of rubber, which was later replaced by leather because of the shortage of rubber. The following is a good description of a typical German facepiece:

“The facepiece of the German mask was made of one piece of leather, with seams at the chin and at the temples, giving it roughly the shape of the face. The leather was treated with oil to make it soft and pliable, also to render it impervious to gases. The dressed surface was toward the inside of the mask. A circular steel plate, 3 inches in diameter, was set into the facepiece just opposite the wearer’s nose and mouth, with a threaded socket into which the drum containing the absorbents screwed. A rubber gasket (synthetic?) held in place by a sort of pitch cement, secured a gas-tight joint between the drum and the facepiece. There were no valves, both inhaled and exhaled air passing through the canister. The eyepieces were inserted by means of metal rims with leather washers, and were in two parts: (a) a permanent exterior sheet of transparent material (‘cellon’) resembling celluloid, and (b) an inner removable disc which functioned as an anti-dimming device. This latter appeared to be of ‘cellon’ coated on the side toward the eye with gelatin, and was held in position by a ‘wheel’ stamped from thin sheet metal, which screwed into the metal rim of the eyepiece from the inside. The gelatin prevented dimming by absorbing the moisture, but wrinkled and blistered and became opaque after a few hours’ use, and could not be changed without removing the mask. The edge of the facepiece all around was provided with a bearing surface consisting of a welt of finely woven cloth about one inch wide sewed to the leather. In some instances this welt was of leather of an inferior grade. The edge of the facepiece was smoothed over by a coat of flexible transparent gum, probably a synthetic compound.”

Fig. 50.—German Respirator.

Fig. 51.—The German Respirator

German Canister. The general appearance of the canister (Sept., 1916 Type) is that of a short thick cylinder slightly tapered and having at the smaller end a threaded protrusion or neck by which it is screwed onto the facepiece. The cylinder is about 10 cm. in diameter and about 5 cm. in length. In the canister are three layers of absorbents of unequal thickness separated by disks of fine mesh metal screen. The canister is shipped in a light sheet iron can 10 cm. in diameter and 8 cm. high. The can is shellacked and is lined with paper packing board. The container is made air-tight by sealing with a strip of adhesive tape.

Fig. 52.—Cross Section of 1917 and 1918 German Canisters.

Absorbents.

Absorbent.Composition.Weight. Volume.
1917. No. 1.Chemical Absorbent.66 gr.105 cc.
No. 2.Impregnated Charcoal.36 gr.85 cc.
No. 3.Chemical Absorbent.15 gr.45 cc.
1918.No. 1.Impregnated Charcoal.58 gr.185 cc.
No. 2.Chemical Absorbent.29 gr.45 cc.
Total Volume of Absorbents,1917, 235 cc. = 14.3 cu. in.
1918, 230 cc. = 14.0 cu. in.
Total Weight of Absorbents,1917, 117 gr.
1918, 87 gr.
Volume of Air Space above Absorbents = 50 cc. = 3.1 cu. in.

Body. The body of the canister is made of sheet metal (probably iron), which is protected on the outside with a coat of dark gray paint and on the inside with a japan varnish. For ease in assembling the sides of the canister have a gentle taper, and are formed so as to supply a seat for each of the follower rings. The protrusion or neck has about six threads to the inch, the pitch of the screw being 4 mm. The lower part of the body is rolled so as to give a finished edge, and the upper part of the cylinder is grooved to receive the top support.

The first screen is double, consisting of a coarse top screen five to six mesh, per linear inch, and immediately below, a finer screen of 30-40 mesh, per linear inch. The top support is a rigid ring of metal with two cross arms, which give added, strength to the ring and support to the screens. It springs into a groove at the top of the body and forms the support for the contents of the canister. Both screens are made of iron wire and the top support is made of iron (probably lightly tinned).

The second screen, which separates the second and third absorbents, is double, consisting of two disks of 30-40 mesh iron screen. Both screens are held in place by a follower ring.

The third screen is single, but otherwise it is exactly similar to the second screen. It serves to keep separate the layers of absorbents No. 1 and No. 2.

The fourth screen (30-40 mesh) is made of iron wire and is held to the bottom support by six cleats which are punched from the body of the support. The bottom support is simply a flanged iron cover for the bottom of the canister. It is punched with 79 circular holes each 4 mm. in diameter and is painted on the outside to match the body of the canister. The screen and the inside of the bottom support or cover are coated with a red paint.