Section 1712 - Kindergartens; nursery and night schools1. The board of education of each school district may maintain kindergartens which shall be free to resident children between the ages of four and six years, provided, however, such board may fix a higher minimum age for admission to such kindergartens.2. A board of education may maintain nursery schools which shall be free to resident children and may fix the age for admission.3. Night schools wherein the common branches and such additional subjects as may be adapted to students applying for instruction are taught on at least two nights each week, for two hours each night, shall be maintained by the board of education and in each school district where twenty or more persons from seventeen to twenty-one years of age are required to attend upon evening instruction, or where twenty or more persons over the age of sixteen years make applications for instruction in a night school, on at least fifty nights. All night schools shall be free to all persons residing in the district.