Whenever any school district organized under a special act of the legislature shall vote to abolish such district and to unite with the town district, if said town district shall vote to receive said special district, and the special district has for the 5 years next preceding such vote maintained a high school, it shall be incumbent on the town district with which it unites to thereafter keep and maintain a high school within the limits of said special district for at least 34 weeks in each year, of equal grade to that which had been previously maintained therein by such special district, said high school to be open to all scholars in the town district, of suitable age and qualifications.