The magistrates and council of any burgh may resolve that from a subsequent date, to be specified in such resolution, the petty customs or duties, or part of them, levied or leviable in such burgh shall be abolished, and that in lieu thereof there shall be levied by way of assessment in such burgh at a rate or rates calculated to yield in the whole in the year an amount equal to the net yearly amount of such petty customs, or part of them, and no more, . . . F1, and from such date such petty customs or duties, or such part thereof, shall be wholly abolished in such burgh, . . . F1: Provided that no such resolution shall have any force or effect unless a month’s previous notice shall have been given of the meeting of the magistrates and council whereat such resolution was moved, and of the intention to move such resolution, in one or more public newspapers circulating within such burgh, and also in the manner in which notices of meetings of magistrates and town councils are usually given in such burgh, and unless also two thirds at the least of the members of the council present at such meeting concur in such resolution.