The man pointing on the left is Dr Fritz Haber, a Nobel winning scientist, who - as well as discovering how to make artificial nitrates and so fertilizer - was the primary advocate of using poison gas.
The use of gas was to change the very nature of war in 1915. Until then, war was seen by all as being about personal courage and honour. The infantry all believed that dash and courage was the key. The British Artillery saw its role as to be fully exposed in the front in the field and firing directly at the enemy who would be in sight.
Honour required that men fought each other face to face.
The use of gas in the upcoming second battle of Ypres ended this idea of personal honour. War became "total" and industrial. The human element was removed. Flame throwers and mass indirect bombardment became the new norms.
There were to be no limits.
The Canadians were going to be amongst the very first troops to live through this change. For them, Ypres in 1915 was going to be what the Somme was to the Kitchener divisions in 1916.
But for now, in January 1915, the plan was for the Canadians to begin the war in a quiet sector. They would arrive in early February.
But as the staff was organizing to add the Canadians into this now quiet sector, Haber was working to change all of this. We have already seen how important Ypres was. If Ypres was taken, Germany could win the war in 1915.
Haber was convinced that the use of gas was going to give his country the edge and enable them to break the deadlock and take Ypres. In January, he was using the full power as his position as Germany's greatest living practical scientist to get the Army to agree.
At first the high command pushed back.
Here is how Crown Prince Rupprecht of Bavaria saw it
When Dr. Haber and General von Falkenhayn stayed with me before the gas trials were carried out in Flanders for the first time I didn't conceal my feelings from them. I consider this new weapon is not only distasteful, but envisage the potential danger from it for our own troops; if the gas is successful in the attack then the enemy will doubtless start to use the same method against us, and with even greater success. In Flanders, as in northern France, the wind seldom blows from the south-east. Predominantly the wind blows west-east, thereby giving ten times more opportunity for the enemy to blow gas towards our positions instead of us blowing it towards him.
In response to my concern I was told by Dr. Haber that our enemy's chemical industry was not capable of producing gas on that large a scale. I replied that this may well be the case at present, but that I doubted it would remain so.”
It was decided to go ahead though. Haber won.
The map above shows us how the final plan was devised.
It was a stroke of fate that, days before the planned attack, the Canadians replaced units in this key position on the right of the main attack.
This was the last time in the Great War where courage made the difference and it was the Canadians, with over 6,000 casualties out of the 18,000, who held the line.
There is massive irony to add.
Haber represents a paradox for science. A patriot, he could only see that the use of gas might be a war winner. Is this not the trap that confronts many scientists? Just because you can does not mean that you should.
As the Crown Prince feared, the British did respond only months later at Loos. Gas became the new normal for everyone. The playing field was levelled but at a more terrible level.
Haber paid a terrible price.
His wife, Clara, deeply ashamed and troubled by this decision and her own part in the research, killed herself in the fall of 1915.
Many scientists in 1919, when Haber received his Nobel, shunned him.
After the rise of Hitler, no credit was given to Haber for his work and his conversion to Christianity was no protection. Many of his family died in the holocaust. Haber's lab had also created Zyklon B, the gas used at Auschwitz. All his patriotism was for nothing.
And the final irony was that his second wife and children were given asylum in England the home of his enemies in 1915.
Haber remains for me a truly tragic figure.
And finally, Haber inadvertently might have saved my grandfather's life. On September 7th 1918, Alec and his entire battery were gassed. He survived and missed the last 2 months of the war when the Canadians had very high casualties.