The submissions that the Amendment Act was not retrospective and that the enhancement of the tax was not made following the procedure prescribed by law, were also negatived holding that the procedure prescribed under the old Act was followed inasmuch as under the old Act the property tax was levied on the basis of only rental value whereas under the new Act it was on the basis either of the rental value or of the capital value, and that under the old Act when tax was being levied on the basis of rental value there was no need to ascertain the capital value of the land and for enhancing the assessment all that the authority had to know was whether there had been an increase in the rent and Rule 6 of Schedule II which dealt with the value of the building for the purposes of property tax was inapplicable as the levy under the old Act on the basis of rental value and enhancement could be done accord ing to the procedure contained in Schedule VII Rule 10 of the old Act.