The Maintenance-of-Way Employees and the Letter Carriers not only limit the age of the insured but also grade the charge per $1000 according to age. In the case of the former, members from eighteen to thirty-five years of age pay $1 monthly per $1000 of insurance; those from thirty-five to forty, $1.25; from forty to fifty, $1.50. Insurance rates in the Letter Carriers' Mutual Benefit Department have, with the exception of the first year of operation, been graded according to age. The minimum and maximum age limits are twenty-one and fifty-five years. The monthly rates vary according to age from 77 cents per $1000 of insurance at twenty-one years to $2.06 at fifty years. The following table shows the regulations as to the amount and rate of insurance issued according to ages: Amount of Insurance Organization. Age Classes. Issued. Engineers ............. Under 40 years. $4500 40 and under 45. 3000 45 and under 50. 1500 Conductors ............ Under 35 years. 3000 35 and under 45. 2000 45 to 50. 1000 Firemen ............... Under 45 years. 3000 45 and over. 1500 Trainmen .............. No age restriction. 1350 Telegraphers .......... 18 and under 45. 1000 45 and under 50. 500 50 and under 60. 300 Switchmen ............. No age restriction. 1200 Maintenance-of-Way Employees ........... 18 and under 45 at graded rates. 1000 Letter Carriers ....... 21 to 55 at graded rates. 1000 to 3000 The necessity for a reduction in the amount of insurance issued to the older men was more urgent among the Engineers and the Conductors than among the other railway organizations, since the latter form the school of apprenticeship from which the engineers and the conductors are drawn. In the Trainmen's and the Switchmen's organizations the young men contribute materially to the cost of insuring the old men. This charge is not so heavy as might appear at first sight, since in both organizations many members withdraw when they are promoted to higher positions in the service. In grading the amount of insurance offered according to age, the brotherhoods have made a compromise between an assessment on each individual according to the liability incurred, and a system in which the welfare of the individual is regarded as entirely at one with the welfare of the membership. The principle of solidarity is still recognized, but under limitations.