In any such county the board of county commissioners shall upon presentation of a petition signed by electors of said county, equal to ten percent of the vote cast for secretary of state at the last preceding general election, submit to a vote of the people the question of the purchase of the necessary ground in said county and the establishment thereon of a juvenile farm for boys. Said question may be submitted at a special election called for that purpose, or at a general election, but said special election may be held at the same time as the city election, in which event a special ballot upon such question shall be provided for the voters at such election. Such question shall appear upon the ballot as follows:

For the “detention home” or juvenile farm   

Against the “detention home” or juvenile farm   

And if a majority of the votes cast for and against such proposition shall be in favor of such establishment, the board of county commissioners shall proceed to establish and maintain the same as herein provided. In like manner a detention home or juvenile farm for girls may be provided in any county containing a city the population of which is not less than 70,000; but propositions for the establishment of more than one home may not be submitted at the same election.