The State Board of Education, upon the recommendation of the State Superintendent of Education, shall designate the site for each of the trade schools and determine the order in which the schools shall be established. The board must devote the entire appropriation herein made for each fiscal year to the establishment of the school required to be established during that year; except that, of the appropriation for each year, $75,000.00 thereof shall be reserved as a fund for operating and maintaining such school. Each school shall be located in a different section of the state and so situated that every part of the state is within as close a radius as is reasonably possible to one of the schools of the Alabama School of Trades at Gadsden. No more than one trade school shall be located in a single congressional district; provided, that the trade school now located in Limestone County, Alabama and owned by the city board of education, Decatur, Alabama, shall, when its support by the federal government is terminated and the school has been conveyed to the State of Alabama, be considered an additional or fifth trade school under the operation of this article, and an additional sum of $75,000.00 per year is hereby appropriated from the Education Trust Fund for the maintenance of said school, the said yearly appropriation to commence upon the termination of federal government support of said school and the conveyance of the same by the city board of education, Decatur, Alabama to the State of Alabama.