2-15-13. Compensation and mileage of convention delegates--Disbursements for convention expenses. Each delegate shall receive five dollars per day for the first five days he is in attendance at said convention, and ten cents per mile for each mile necessarily traveled in going to and returning from said convention. The secretary and other officers shall receive such compensation as may be fixed by the convention. Disbursements for the foregoing purposes and for other necessary expenses of the convention, when approved by the convention and signed by the president and secretary, shall be made by the state treasurer out of any appropriation available therefor.