Sir Douglas Haig

General Sir Douglas Haig was commander of the British 1st Army, making him one of Britain’s most senior soldiers. In September 1915, Douglas Haig was ordered by BEF commander, Field Marshal Sir John French, to prepare an attack on German trenches in the Loos area of northern France, to commence on the 25th. But every week the German lines got stronger. It was a daunting prospect.

In desperation, Haig decided to release poisonous chlorine gas. The problem was that he needed winds of the right strength and direction to carry the gas across to the German lines.

Assisting Haig in making his decision was Britain’s leading meteorologist, Ernest Gold. Haig spent much of the night before the battle monitoring the weather forecasts. Mr Gold arrived. His weather charts were most interesting, but his forecast for a favourable wind was not very encouraging. Mr Gold at 6pm reported telegrams from

With so much at stake, tension was high at 1st Army headquarters during the early hours of 25 September.

The greatest battle in the world’s history begins today – some 800,000 French and British troops will actually attack today.

At 3am, I saw Mr Gold. Wind in places had fallen to 1 mile per hour. He could not say anything definitely beyond that the wind would probably be stronger just after sunrise. I went out at 5am – almost a calm. Alan Fletcher lit a cigarette and the smoke drifted in puffs towards the north-east.

At one time owing to the calm I feared the gas would simply hang about our trenches! However, at 5.15, I said: “Carry on.” I went to top of our lookout tower. The wind came gently from south-west and by 5.40 had increased slightly. The leaves of the poplar gently rustled.

The decision was taken.