It is ordered that each member of the advisory board of engineers upon plans of the Panama Canal shall be allowed $5,000, payable upon the completion of the report of the board. In addition thereto he shall, when on duty with the board, be allowed $15 per day for personal expenses from the date of leaving his home until his return thereto, including Sundays and Holidays. He shall also be allowed the actual cost of transportation incurred by him in travel on duty in connection with the board to include cost of ticket by railway or steamer, sleeper or parlor car accommodations, baggage transportation, cabs and porterage.
It is further ordered that the allowance of $5,000 to Gen. Davis and Gen. Abbott shall be increased by the amount of their retired pay for the time during which they are employed upon the work of the board, it being my intention that these members of the board shall receive the same compensation for this work as the other members, and this increase being made to provide for the usual reduction of retired officers' pay.
Theodore Roosevelt, Executive Order Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/206636