“§ 34. That no rate or assessment to be made under the authority of this act shall be valid, unless notice of the intention of making such rate or assessment, and of the time at which the same is intended to be made, and of the place where a statement of the proposed rate shall be deposited for inspection, shall be given by the clerk of the trustees by circular to all the proprietors and feuars intended to be charged with such rate, or their respective agents , and posted at Glasgow at least seven days previously to such rate being made.