The Council shall cause to be made up annually and entered upon its journal an accurate estimate of all sums which are or may become lawfully chargeable on said Town, and which ought to be paid within one year, and it shall order a Town levy of so much, in its opinion, as may be necessary to pay the same; provided, however, that the tax rate shall not exceed thirty-five cents on the one hundred dollars, except where it appears to the satisfaction of the Council that a levy of thirty-five cents on each one hundred dollars will not produce sufficient revenue in any one year to pay current expenses, the interest on the bonded indebtedness of the Town, and provide for a sinking fund sufficient to liquidate such bonded indebtedness within the time prescribed by law; and in such case, the Council may, by a vote of a majority of all members elected to the Council, increase such tax rate to such a rate, not exceeding fifty cents on the one hundred dollars, as may be necessary for the purpose aforesaid. All vacant property embraced in the proposed boundaries of the said Town, beyond the old limits of the Town, shall be subject only to such taxation for the benefit of said Town, as is levied upon other property for county and district purposes, and until the said vacant property shall be divided into lots for building purposes, and offered for sale as such, and until the streets of the said Town shall be opened for the use and accommodation of the same.