The board of directors of the public library of any township, which has issued bonds pursuant to the provisions of this Act, shall, on or before the first Tuesday in August, of each year, ascertain as near as practicable, the amount of money which must be raised by special taxation for the ensuing year, for the purpose of paying the interest upon such bonds and the principal thereof, as they respectively become due; and shall cause the same to be certified, under the signatures of the president and secretary of such board of directors, and filed in the office of the county clerk of the county in which the library is situated, on or before the second Monday in August of each year; which certificate may be substantially in the following form:
     We certify that the Board of Directors of the …. Public Library has determined that it will require the sum of $……, to be levied as a special tax upon the taxable property of …. Township, for the year (insert year), for the purpose of paying the bonds of the Township and the interest thereon.
     Dated (insert date).
     Board of Directors of …. Public Library.