This happy state, unfortunately, did not long continue; and looking back the reasons are now quite clear. When the war broke out unemployment was generally feared, so much so that a Government Committee on the Prevention and Relief of Distress was appointed which invited mayors and provosts throughout the country to form local committees to deal with unemployment. The Local Government Board urged local authorities to expedite public work; even the Director of Army Contracts appended to Government contracts a memorandum advising contractors that in executing the work they should arrange for the employment of as large a number of men as possible instead of working overtime. By December 1915, not unemployment, but a grave shortage of skilled engineering workmen proved to be the national difficulty. Various attempts were made to remedy the shortage; first, by transferring skilled men from commercial work to munitions work; next, by obtaining the release of skilled men from the Colours; thirdly, by importing skilled Belgian refugees and mechanics from Canada; fourthly, in some districts, by forming “king’s squads” or mobile companies to work wherever they were most needed. All these methods proved quite inadequate and the sole remaining course left open was to make the best use of the skilled men who were actually available, that is to say, to remove them from work on which unskilled men or women could be employed and up-grade them on to the most difficult skilled work which only a tradesman could undertake, or put them as supervisors over the unskilled labour so brought in. This is what was popularly known as “dilution,” but its successful introduction involved a definite suspension of Trade Union customs.