A computation has been made of ton mileage on each individual mail route by multiplying weight carried by length of route; to the sum of these we add the dead weight of cars. The report of the Second Assistant Postmaster-General for year ending June 30, 1908, page 32, gives the number of cars engaged in mail service, which we have multiplied by the average mileage made by the average car, based on experience of the Union Pacific and Southern Pacific Systems, to ascertain total car mileage for the United States. Multiplying this by the dead weight of a car gives the ton mileage of dead weight, which, added to the ton mileage of mails, gives the gross ton mileage, measure of work and cost imposed on the railroads in return for the pay they receive for handling the mails. These computations are shown in the following statements, the results being conservative, as for want of accurate data it has been necessary to omit some work which the railroads do, which, if ascertainable, would increase the cost. For example, we have made no charge for the dead weight of that portion of baggage cars devoted to the handling of pouch mail, such pouch service, according to the Postmaster-General's report, covering annually on railroads and express trains 122,027,597 miles; nor for the dead weight of storage mail cars provided by the railroads. Neither has any account been taken of the value of transportation given mail clerks, which, based on the Postmaster-General's report of 1908, amounted to 629,778,443 miles, which at 2 cents a mile would be $12,500,000; nor for the value of transportation or postal commissions of Postoffice Department officials; nor does it take into account special service rendered by the railroads, such as delivering mail at stations, value of space furnished by the railroads and required of them by the Postoffice Department at important junction and terminal points for mail distribution and accommodation of government transfer clerks. The statistics of passenger service in the following statements are based on the 1907 Annual Report of Statistics of Railways published by the Interstate Commerce Commission (1908 figures, which would show higher operating cost, not available), with the exception that the average mileage per car per annum run by passenger cars is based on the experience of the Union Pacific and Southern Pacific Systems. Statistics of freight service are likewise based on the 1907 Report of Statistics of Railways, freight car mileage being actually reported by the Interstate Commerce Commission, dead weight per car being computed from all freight cars handled on Union Pacific and Southern Pacific Systems. MAIL SERVICE. Year Ending June 30, 1908.