"Weaponry: Use of Chlorine Gas Cylinders in World War I" "Weaponry: Use of Chlorine Gas Cylinders in World War I" Battle of Ypres "Weaponry: Use of Chlorine Gas Cylinders in World War I" "Weaponry: Use of Chlorine Gas Cylinders in World War I" "Weaponry: Use of Chlorine Gas Cylinders in World War I" Battle of Ypres "Weaponry: Use of Chlorine Gas Cylinders in World War I" "Weaponry: Use of Chlorine Gas Cylinders in World War I" "Weaponry: Use of Chlorine Gas Cylinders in World War I"