1. These are one hundred and eighty-two petitions under Art.226 of the Constitution preferred by operators of stage carriages on several routes in the erstwhile Travancore-Cochin State, for the issue of a writ of certiorari, or other appropriate writ, direction or order, quashing the notification, TB-2/14667/57/PW dated the 24th September, 1957, made by Government, by virtue of the power conferred on them by S.18(1) of the Travancore-Cochin Vehicles Taxation Act, 1950, referred to hereinafter as the Act. The Act has provided for the levy of a tax on every vehicle using any public road in the Travancore-Cochin area, and has prescribed in Schedules I and III thereof, the maximum tax leviable for each class of vehicles. S.3, sub-sections (1) and (2) of the Act authorised Government, to specify, by notification inter alia the rate at which, the tax shall be levied for each class of vehicles, which, under the proviso to that section, "shall not exceed the maxima specified in Schedule I in the case of motor vehicles, and the maxima specified in Schedule III in the case of vehicles other than motor vehicles". Pursuant to this, Government issued notifications specifying the rat