The impact of the First World War on the lead companies – rising profitability, control of lead supply by the Ministry of Munitions, encouragement towards amalgamation. The lead industry had largely missed the merger boom of the 1890s and had controlled competition by means of cartels. Although the merger had shown signs of being formalised with the formation of Associated Lead Manufacturers Ltd in 1919, there were clearly serious difficulties which were to lead to its failure. Capital expenditure, for instance new blast furnaces at Elswick and Chester, a new rolling mill and expansion of the red lead capacity, had helped to bring the firm up-to-date in technology and reduce manufacturing costs. On the other hand the lead manufacturers were making very good profits, even on reduced output and had no great incentive to look to amalgamation. This position continued into the post-war boom but from the slump of 1921 the factors changed.