Detailed reference will now be made to the methods and controlling effect of the Postmaster-General's apportionment of passenger train space between the mails and the other services rendered on passenger trains. Such an apportionment was a necessary step in the calculations reported in Document No. 105. Having obtained certain estimates of the cost of the passenger train services, considered together, by methods, producing the lowest results, the next step shown in Document No. 105 was to apportion a part of this cost to the mail service. The accepted method for such an apportionment is to distribute the total cost in proportion to the train space required by each of the respective services. The Postmaster-General obtained from the railways statements which he might have used in applying this method and these statements showed that 9.32 per cent. of the total space in passenger trains was required by the mails, but, instead of using the data showing this fact, he substituted figures of his own which reduced the space credited to the mail service to 7.16 per cent. of the total. The total of passenger train costs which the Postmaster-General estimated should be apportioned among passengers, express and mail, on the basis of space occupied, was $37,074,172.[D] He therefore assigned to the mail service 7.16 per cent. of the last-named sum or $2,654,510.69. If, however, he had used the proportion of space, 9.32 per cent., resulting from the reports he had obtained from the railways, the amount apportioned as cost of the mail service for the month would have been $800,802 greater. Multiplying this by twelve gives an increase in the estimated annual cost of over $9,600,000. [Footnote D: This is the sum which was apportioned by the Postmaster General on the basis of train space occupied. He estimated $40,121,294.83 (Document No. 105, page 280) as the total operating expenses and taxes of the passenger train services for the month. Of this total $21,993.06 was charged directly to the mails and $3,025,129.77 directly to the other passenger train services, leaving the sum stated in the text to be apportioned on the space basis.] Thus the Postmaster-General arrived at his declaration that the railways were getting an excess profit of $9,000,000 by means of two fundamental errors, omitting for the present reference to any other errors. He understated the annual mail expenses and taxes of the railways by at least $9,600,000, and he ignored entirely the necessary return on the value of railroad property.