On the organization of the first board of directors of any such district they shall designate some place within the district as the office of said board: provided, that the board of directors may establish the office of the district temporarily outside of the boundary of the district, but within the county in which the same or some portion thereof is situated, in cases where the business of the district may be more conveniently transacted thereby; and if such temporary location be approved by a majority of the electors of the district voting at any regular election at which such question may be submitted then such temporary location may be fixed as the location of the office of the district for such period of years as may be designated on their ballots by the majority of such electors at such election.