Protection of Animals

Horse Mask. The need of protection for animals (horses and dogs), although not as great as in the case of men, was of sufficient importance so that masks and boots were developed for the horse and a mask for the dog.

The German horse mask was the first produced. It was of the nose bag type, enveloping the mouth and nose of the animal. It was fitted with a complicated drawstring and with snap hooks fastening it to the harness. The interior contains a plate of stiff material to prevent the collapse of the bag. The mask itself was apparently not impregnated, but was used wet or with a filling of wet straw or rags to act as the absorbent.

Fig. 82.—German Respirator for Horses.

The French had two types of horse masks impregnated with a glycerine-nickel hydroxide mixture. One type had a closed bottom, while in the other, the bottom was open.

The British horse mask has a two-layer flannelette bag, with a canvas mouth pad and elastic drawstring. It was impregnated with a mixture of phenol, formaldehyde, ammonia, canister soda and glycerine.

The first type of American horse mask was modelled after the British and was impregnated with the Komplexene mixture (hexamethylenetetramine, glycerine, nickel sulfate mixture). This mask had too high a resistance and caused complete exhaustion in running horses. The second mask was made of a large number of layers of very open cheesecloth. It consists of two bags, impregnated with different mixtures (Komplexene and Simplexene). Horses can run two miles with this mask without showing evidences of exhaustion.

Dewey gives the following method of manufacture:

The chemical employed consisted of a mixture of hexamethylenetetramine (to give protection against phosgene), nickel sulfate (to protect against the possible use of hydrocyanic acid), sodium carbonate and glycerine. This solution was mixed in a heavy steam jacketed mixing kettle with heavy geared stirrers. The mixture was conducted by pipes to the impregnating apparatus which consisted of a rotary laundry washing machine. The masks were treated in this machine for 15 minutes, and then placed in a power operated wringer and the solution driven off to a given weight. Following this operation, they were suspended on wire supports and conducted through a hot air drying machine and dried to a definite weight. 378,000 horse masks were produced at the rate of 5,000 per day.

Fig. 83.—Horse Mask—American Type.

Theoretically, horse masks and horse boots are very valuable,—practically, they did very little actual good in the field, not that they would not protect or that animals would not wear them. The trouble was with the riders and drivers. Gas attacks, coming usually at night, made adjustment of horse masks difficult at best, while in the confusion of bursting shell and smoke, the drivers absolutely forgot the horse masks or after putting on their own masks feared to try putting masks on the animals. This last was natural as most animals fight the adjustment of the mask and in so doing there is great risk that the man’s mask may be torn off and the man gassed. In the future, such masks will have even more importance than in the past, for the present methods of manufacture of mustard gas coupled with its all-round effectiveness will cause a use of it ten-fold greater than at any time in the World War. In such cases, operations will necessarily be frequently carried on over large areas thoroughly poisoned with mustard gas. Here the animals will be masked and booted before entering the gassed area, and remain so until they leave it. In the torn and broken ground around the front line there will always be need for animal transportation,—wagon, cart and horse—as in such places it is far better in nearly all cases than motor transport.

Dog Mask. The use of dogs in messenger service and in Red Cross work, in which gassed areas must be passed, led to the designing of a mask to give the animals suitable protection. The same materials and method of impregnation were used as in the horse mask. With eight layers of cheesecloth, adequate protection against mustard gas was secured with practically no pressure drop.

The eyepieces were made of thin sheets of cellulose acetate bound around the edge with adhesive tape and sewed directly over openings cut through the mask fabric. The ear pockets were made round and full enough to fit pointed or lop-eared animals. The mask is continued to form a wide neck band which may be drawn up by two adjustable straps. It is made sufficiently full to allow a free movement of the dog’s jaws and yet tight enough around the neck to avoid the possibility of being pawed off. The dog apparently soon became accustomed to wearing the mask.

Horse Boots. The increasing amount of mustard gas used on the Western front made it seem necessary to develop some form of protection for the horse’s hoof and fore-leg. It has been found that mustard gas vapors attack the fleshy portion of the leg, especially around the coronary band and causes inflammation of the frog of the foot. The problem was solved by devising a special hoof pad and a boot. The pad was made of sheet iron imbedded in a hoof protector (composition rubber) to which the shoe is applied. The shoe just overlaps the metal plate on the inside and provides a solid metal surface for the bottom of the foot. Such a pad not only offers protection against gas but against shell splinters, barbed wire, etc., and would be useful at all times on the front.

Fig. 84.—Impervious Boots and Pads to Protect
Horses’ Legs and Hoofs against Mustard Gas.

Fig. 85.—Protective Gas Outfit—Gas Mask, Gas Suit,
Gloves, Boots, Horse Mask, Horse Boots, Horse Pads.

The boot was made of satin, treated so as to be impervious to mustard gas. It covers all of the foot except the bottom and extends to just below the knee. The boot is held in contact with the hoof by a sewed cloth strap, which passes around the bottom of the hoof and is held in position by projections extending from the spur or toe clip. Special care is taken to insure a perfect joint at the rear of the boot since the small cavity in the back of the hoof is one of the most sensitive parts. The boot is wrapped about one and a half times around the leg and is clipped with five loops through which passes a ¾-inch strap.

Dugout Blankets. Dugout protection is intended to prevent entrance of any gases, lethal, lachrymatory or irritant, into the enclosed space. This has been most efficiently accomplished by means of curtains hung upon wooden frames and fitting closely against all edges of the opening to be closed. These curtains have usually been of heavy material and have generally been spoken of as dugout blankets. Since they were designed to exclude all toxic gases, they had to be devised upon general mechanical principles rather than upon principles of chemical action with specific gases. Permeability to air has not been considered a necessity, it being held that sufficient ventilation is secured by means of the air entering through the soil. For large dugouts and extended use large air filters were designed to draw pure air into the dugout with a fan.

The qualities aimed at, to which both fabric and treatment should contribute, are the following:

Army blankets, both those for men and those for horses, proved suitable materials for curtains, but the scarcity of wool made it desirable to select an all cotton fabric.

A large number of oils were studied as impregnating agents. The most satisfactory mixture consisted of 85 per cent of a heavy steam refined cylinder oil and 15 per cent of linseed oil. This is taken up to the extent of about 300 per cent increase in weight of the blanket during impregnation. It becomes oxidized to some extent upon the surface of the blanket, which becomes less oily than the soft, central core. The finished blanket possessed the following properties: It resists penetration of 400-600 p.p.m. of chloropicrin for 8 hours (dugout test) and mustard gas for 100-400 minutes (machine test). It is sufficiently flexible after standing for 2 hours at 18° F. to unroll of its own weight, and may be unrolled by applying a slight force at 6° F.; it is not ignited by lighted matches and shows but little loss by drainage.

Two types of machines were designed for impregnation, one for use on large scale behind the line, and a field apparatus for use at the front.

CHAPTER XVI
SCREENING SMOKES

The intelligent use of screening smokes in modern infantry tactics offers innumerable advantages through concealment and deception. It confers upon daylight operations many of the advantages which were gained by conducting operations at night with few of the disadvantages of the latter.

Smoke screens have been frequently used by the Navy and by Merchantmen; a common method of escape was to shut off the air from the fire with consequent incomplete combustion of the fuel, thus causing a cloud of dense black smoke. This is often mentioned in the blockade runners of the days in the Civil War, where wood, high in pitch and rosin, was freely introduced into the furnaces, in order that they might escape under cover of this smoke.

Early in the present war it was found that black smoke had a low obscuring power, showed frequent rents or holes and were difficult to standardize. Their production also caused a considerable loss in the speed of the vessel. They therefore fell into disuse except for emergency purposes and today the standard smoke for screening purposes of all kinds is, without exception, white.[33]