According to the Home Office Statistics of Compensation paid during the year 1938, nearly 40% of the number of cases of compensation in the seven main groups of industries in Great Britain occurred in the mining industry, and 80% of the compensation to workers in the industry is paid by employers who insure their Workmen's Compensation risk with Mutual Indemnity Associations. As these Coal Trade Mutual Indemnity Associations deal with about one-third of the compensation paid in the seven main industrial groups, the experience of the larger associations is capable of useful analysis according to the age of the workman, the cause and effect of the accident or industrial disease, and the degree and duration of the resulting incapacity.