But the spirit of the infantry in this work, as in all they undertook, is to their everlasting credit. These tasks were an enemy challenge and they accepted it successfully, albeit with much cursing. The work was indeed beyond description and the country, colonial, and London troops expressed their opinion equally emphatically in their own peculiar way. Think again of the need of systematic wind observation along the whole front of attack, the disorganisation and "gas alert" conditions imposed on the favourable night, the possibility of postponement, and we can only draw one conclusion. There must have been some imperative need or justification of cloud gas attack for the army to have encouraged or even tolerated its continuance. There is no difficulty in understanding why gas attack was so exceedingly unpopular among the staffs in the early stages of the war. Later, however, when they realised the enemy casualties that were being created by the gas, and what a large part it was taking in the war of attrition, the opposition and lack of appreciation vanished. Further, when the projector arrived to produce similar effects with less demand upon infantry personnel, and less dependence on the wind, the whole tone of the army towards gas was changed, and it became almost popular.

The peculiarity of cloud gas attack was the concentration of all this effort of preparation within a few days. In terms of military efficiency, the amount of energy expended was fully justified by the casualties produced. We know that some of our cloud attacks were responsible on one night for many thousands of casualties, and the amount of artillery effort to give such a result would probably have been considerably larger. But under normal conditions of warfare, such artillery effort would have been expended over a much longer period of time.

The Livens Projector.—The Somme offensive witnessed the use of a new British gas weapon which became of the utmost importance. This was the mortar known as the Livens Projector. Its origin dates back many months, however, and is of considerable interest. A British engineer, Lt. Livens (afterwards Major, D.S.O., M.C.) of the Signal Corps, was inspired to constructive and aggressive thought on the gas question by a double motive. He quickly realised the tactical weakness of the German method at Ypres, once shorn of its vast initial possibilities of surprise. He saw the advantage of being able to command the point or locality of incidence of the cloud, instead of being limited to the actual trench front. Prompted by a direct personal interest in the huge loss sustained by the Lusitania outrage, he determined to find a practical outlet for his feelings by developing his views on the future of gas clouds. In a few months the general principles of the projector were defined and a crude specimen resulted. Caught up, however, in the gas organisation, preparations for the cloud attack at Loos absorbed all his attention and energies and the consequent reorganisation found him developing a flammenwerfer and training a company for its use. It was really the Somme battle which gave him the first opportunity to carry his idea into offensive practice. This arose in front of High Wood, which was a veritable nest of German machine gunners in such a critical tactical position as to hold up our advance in that region. The huge stationary flammenwerfer had recently been used by Major Livens and his company against a strong point in front of Carnoy in the assault of July 1st. Here again the effect of flame was limited even more than that of cloud gas by dependence on a fixed emplacement. It was quickly grasped that the solution was to be found in the application of the projector principle to the use of oil for flame and a crude projector was devised for the emergency, using oil cans as mortars, burying them in the earth for two-thirds of their length and employing water cans as bombs.

As soon as the possibilities of the weapon were seen its development was pressed. The usual Livens Projector consisted of a simple tube mortar or projector closed at one end, and fitted with a charge box on which rested the projectile. By an electrical arrangement and suitable communications, large numbers, sometimes thousands, of these projectors could be discharged at a given moment. In this way quantities of gas, comparable with the huge tonnages employed in the normal stationary cloud attack, could be used to produce a cloud which would originate, as cloud, as far as a mile away from the point of discharge. In other words, the advantages of cloud attack could be used with a much smaller dependence on wind direction, and with a much greater factor of local surprise. Thus when the partially perfected and efficient weapon was used in large quantities during the British Arras offensive in April, 1917, the German Army was thrown into great consternation. But for the fact that protection had developed so strongly on both sides, the use of the Livens Projector would have gone far towards a decision.

The simplest way to illustrate the peculiar value of the projector will be to quote from one or two of the many Intelligence reports collected. Thus from a captured document dated July, 1917, belonging to the 111th German Division, signed Von Busse, we have: "The enemy has combined in this new process the advantages of gas clouds and gas shells. The density is equal to that of gas clouds, and the surprise effect of shell fire is also obtained. For the bombardment the latter part of the night is generally chosen, in a calm or light wind (the direction of the latter is immaterial). The enemy aims essentially at surprise. Our losses have been serious up to now, as he has succeeded, in the majority of cases, in surprising us, and masks have often been put on too late. . . . As soon as a loud report like a mine is heard 1000-1500 metres away, give the gas alarm. It does not matter if several false alarms are given. Masks must not be taken off without orders from an officer. Men affected, even if apparently only slightly, must be treated as serious cases, laid flat, kept still, and taken back as soon as possible for medical treatment. Anti-gas officers and Company Commanders will go through a fresh course of training on the above principles." The influence of gas discipline is borne out by another captured statement that they could only attempt to "reduce their losses to a minimum by the strictest gas discipline." Again, from a prisoner we learn that "every time a battalion goes into rest, masks are inspected and a lecture is delivered by the gas officer on British gas projectors, which are stated to be the most deadly form of warfare." So great was the impression formed by the introduction of the projector that uneasiness at the front was reflected later on in the Press. Thus, quoting from reference to the military discussion before the main committee of the Reichstag. "Casualties from enemy poison gas admit on the whole of a favourable judgment, as the harm involved is only temporary, and in most cases no ill after-effects persist" (Tagliche Rundschau, 24.4.18). "Cases of gas poisoning are not as a rule accompanied by harmful consequences, even though the treatment extends sometimes over a long period" (Vorwarts, 25.4.18), Based on the later mustard gas casualties these statements would have been more truthful. As it was, they afforded poor consolation to the German people.

British Gas Shell.—The British first used shell gas as lachrymators, in trench mortar bombs, in small quantities, during the battle of the Somme, but for the first time, during the battle of Arras, 1917, our supplies of gas for shell were sufficient for extensive and effective use. Our success can be measured by the report dated April 11th, 1917, from the General Commanding the first German Army, on "Experiences in the Battle of Arras," in which he says: "The enemy made extensive use of gas ammunition against our front positions as well as against batteries." "The fighting resistance of the men suffered considerably from wearing the mask for many hours." Artillery activity seems to have been paralysed by the effects of the gas.

In a general comparison of British and German methods of gas warfare,[1] General Hartley tells us "our methods improved rapidly during 1917. At first we neglected, almost entirely, the question of rate of firing, but we soon arrived at the method of crashes of lethal shell. These got the surprise concentrations of gas which proved so effective, and we realised that the number of shells required to produce an effect was much bigger than we thought originally. At Messines gas was used in much the same way as at Arras."

[1] Journal of the Royal Artillery, February, 1920.

German Gas Shell Development, 1916.—The main evidence of Allied reaction was to be found in the intensive development of cloud gas attacks, but during the same period the Germans, who appeared to be abandoning the use of cloud gas, were making steady efforts to regain their initiative by the comprehensive development of shell gas. Thus, to quote from General Hartley's report to the British Association, "In the Summer of 1916 chlor-methyl-chloroformate with toxic properties similar to those of phosgene was used against us in large quantities during the battle of the Somme. Later this was replaced by trichlor-methyl-chloro-formate, a similar liquid, which was used until the end of the war as the well-known Green Cross shell filling. The use of phosgene in trench mortar bombs also began in 1916." Many of those on the front in 1916 will remember the surprise gas shell attack of December of that year, on the Baudimont gate at Arras. We were fortunately let off lightly with little over 100 casualties, but the effect was to tighten up gas discipline all along the line. The appearance of the new substances represented definite German progress and had definite military results, but they lost decisive value owing to the relative inefficiency of German gas shell tactics.

Consideration of the Allied reaction must include some reference to the appearance of the American Army in the field. The Americans during their more or less educational period gave serious attention to the gas question, and showed almost immediately, by their preparations, that they attached enormous importance to the new weapon.