When the upset price of any entailed lands, the sale of which has been authorized by the Court shall have been fixed, the Court may authorize the lands to be exposed by the heir of entail in possession, in presence of the judge of the roup appointed by the Court, at such time and at such upset price, not being under the said fixed upset price, as the heir of entail in possession may arrange, and in the event of the lands not being sold at such upset price, then the heir of entail in possession may re-expose the lands at a reduced upset price, not being under the said fixed upset price, in presence of the judge of the roup, and so on thereafter if the said lands shall not be sold at such re-exposure: Provided always, that such heir of entail in possession shall advertise the land in the first and subsequent exposures, if any, in terms of the interlocutor which shall have been pronounced by the Court on authorizing the sale, and upon the heir of entail effecting a sale in virtue hereof, the Court shall approve of such sale according to the existing law and practice.