Judgment :- 1. The petitioners in these two Original Petitions are public limited companies owning tea estates in the Kerala State. The petitioner in O. P. 2173 of 1966, namely the Travancore Tea Estates Co., Ltd., Vandiperiyar, owns eight tea estates situated contiguously to each other in Peermade Taluk of Kottayam District and having an extent of 9422.44 acres in the aggregate. It is stated that the Company has constructed roads within the aforesaid estates having a total length of 131 miles for the purposes of effectively carrying out the work of plantation. It is further stated that the Company owns seventeen motor vehicles consisting of tractors, trailers and lorries and that they are intended and kept exclusively for use within the estates. Similarly, the petitioner in O. P, 2081 of 1966 is the owner of three tea estates in Peermade Taluk having a total extent of 2715 acres and it is stated that it has constructed and is maintaining private roads within the estates having a length of about 50 miles. This Company owns five motor vehicles consisting of four tractors with trailers and one lorry and it is alleged that these vehicles have been purchased by the Company solely and exclusively for use in the estates and are also actually used only accordingly. The aforesaid vehicles owned by the petitioners have been duly registered under the Motor Vehicles Act. On their having been called upon to pay motor vehicles tax in respect of the said vehicles under the Kerala Motor Vehicles Taxation Act, 1963 (hereinafter referred to as the Act) the petitioners raised the objection that the tax imposed under the aforesaid Act is in the nature of a compensatory tax and will therefore be leviable only in respect of vehicles used on public roads and that the petitioner's vehicles not being intended or kept for use on public roads within the State are not liable to tax under the said Act. They also contended that they were entitled to exemption from tax under S.20 of the Act on the ground that the motor vehicles in question were designed for agricultural operations relating to food crops and were used solely for such operations in relation to their own lands. The Regional Transport Officer, Kottayam rejected these contentions by the orders evidenced by Ext. P4 in O. P. 2081 of 1966 and Ext. The Regional Transport Officer, Kottayam rejected these contentions by the orders evidenced by Ext. P4 in O. P. 2081 of 1966 and Ext. P8 in O. P. 2173 of 1966. The petitioners have come up to this court seeking to quash the aforesaid orders passed by the Regional Transport Officer and praying for the issuance of an appropriate writ or order directing the respondents to forbear from taking any action against the petitioners for recovering from them motor vehicles tax in respect of the above mentioned vehicles. In O. P. 2173 there is a further prayer that the respondents should be directed to refund to the petitioner an amount of Rs. 3150/-already collected from the Company by way of motor vehicles tax on threat of coercive process. 2. The Act was enacted by the State Legislature with a view to unify and amend the laws relating to levy of tax on motor vehicles in the State of Kerala. Prior to the enactment of this Act there were two different enactments in force in the State, namely the Madras Motor Vehicles Taxation Act, 1931 in the area referred to in S.5 (2) of the States Reorganisation Act as forming the Malabar District, and the Travancore-Cochin Vehicles Taxation Act, 1950 in the area which formed part of the erstwhile Travancore-Cochin State. The Act was brought into force with effect from 17 1963. S.3 of the Act which is the charging Section reads as follows: "Levy of tax (1) Subject to the other provisions of this Act, on and from the date appointed under sub-section (3) of S.1, a tax at the rates fixed by the Government by notification in the Gazette, not exceeding the maximum rates specified in the First Schedule, shall be levied on all motor vehicles used or kept for use in the State: Provided that no tax shall be levied on a motor vehicle kept by a dealer in, or a manufacturer of, such vehicle for the purposes of trade and used under the authorisation of a trade certificate granted by the registering authority. (2) The registered owner of, or any person having possession or control of, a motor vehicle, of which the certificate of registration is current, shall, for the purposes of this Act, be deemed to use or keep such vehicle for use in the State except during any period for which the Regional Transport Officer has certified in the prescribed manner that the motor vehicle has not been used or kept for use. (3) Notwithstanding anything contained in sub-section (1), the Government may, by notification in the Gazette, from time to time direct that a temporary licence for a period not exceeding thirty days at a time may be issued in respect of any class of motor vehicles on payment of such tax (not exceeding the maximum specified in Schedule II) and subject to such conditions as may be specified in such notification. (4) In the ease of motor vehicles in respect of which any reciprocal arrangement relating to taxation has been entered into between the Government of Kerala and any other State Government, the levy of tax shall notwithstanding anything contained in this Act, be in accordance with the terms and conditions of such reciprocal arrangement: Provided that the tax leviable under any such arrangement shall not exceed the tax leviable under the First Schedule or the Second Schedule, as the case may be: Provided further that the terms and conditions of every such reciprocal arrangement shall be published in the Gazette and a copy thereof shall be placed before the Legislative Assembly." Sub-section (1) provides that, subject to the other provisions of the Act, with effect from the date on which the Act is brought into force a tax at the rates fixed by Government by notification in the Gazette shall be levied on all motor vehicles used or kept for use in the State. The proviso to the said sub-section exempts from such levy motor vehicles kept by a dealer or manufacturer for the purposes of trade and used under the authorisation of a trade certificate granted by the registering authority. The proviso to the said sub-section exempts from such levy motor vehicles kept by a dealer or manufacturer for the purposes of trade and used under the authorisation of a trade certificate granted by the registering authority. By sub-section (2) it is prescribed that every motor vehicle of which the certificate of registration is current shall for the purposes of the Act be deemed to be used or kept for use in the State by the registered owner or other person having possession or control thereof except during any period in respect of which the Regional Transport Officer has certified that the motor vehicles had not been used or kept for use. S.5 enables the registered owner or person having possession or control of the vehicle to obtain exemption from tax in respect of periods during which the vehicle is not intended to be used or kept for use by giving previous intimation in writing to the concerned Regional Transport Officer and surrendering to that authority the certificate of registration and permit, if any, of the vehicle. Under S.20, motor vehicles owned by agriculturists and which are designed for agricultural operations relating to food crops and are used solely for such operations in relation to their own land are exempted from the payment of the tax. Power is conferred on the Government under S.22 to exempt from taxation or to reduce or modify the tax payable by such person or class of persons or in respect of such vehicles or class of motor vehicles provided it is found necessary in the public interest so to do. The remaining provisions in the Act are not relevant for the purposes of this case. 3. The main contention advanced before me on behalf of the petitioners is that the Act is really a compensatory tax and that therefore it would not have been the intention of the legislature to impose such tax in aspect of vehicles which are not intended to be used or actually used on the public roads. Counsel for the petitioners submits that the court must have due regard to the state of the law that obtained immediately prior to the passing of the Act as forming the background against which the statute has been enacted by the legislature. Counsel for the petitioners submits that the court must have due regard to the state of the law that obtained immediately prior to the passing of the Act as forming the background against which the statute has been enacted by the legislature. It is pointed out that under S.3 of the Travancore-Cochin Vehicles Taxation Act, 1950 the tax was leviable only on vehicles using any public roads in the State and that the position was substantially the same under the Madras Motor Vehicles Taxation Act, 1931 also. 4. Counsel relied very strongly on the decision of the Supreme Court in Automobile Transport Ltd. v. State of Rajasthan, AIR. 1962 SC. 1406, where their Lordships have described the taxes imposed under the Rajasthan Motor Vehicles Taxation Act as compensatory taxes. The question raised before their Lordships was whether the imposition of the taxes under the Rajasthan Motor Vehicles Taxation Act constituted a violation of the freedom of trade, commerce and intercourse throughout the territory of India guaranteed by Art.301 of the Constitution of India and it was in that context that their Lordships observed that regulatory measures or measures imposing compensatory taxes for the use of trading facilities did not come within the purview of the restrictions contemplated by Art.301 and need not therefore comply with the requirements of the proviso to Art.304 (b) of the Constitution, In my view, this decision is no authority in support of the proposition put forward by the counsel for the petitioners that the legislature has no power to impose a tax on Motor Vehicles kept for use within the State unless those vehicles are intended to be used or are used on public roads maintained by the State. 5. Another argument advanced by the learned counsel was that the court should attach due weight to legislative practice in interpreting the words used in the statute and in support of this contention the observations of the Supreme Court in The State of Madras v. M/ s Gannon Dunkerley & Co., (Madras) Ltd., AIR. 1958 SC. 560 at p. 569 regarding the interpretation to be placed on the expression "sale of goods" occurring in entry 48 of List II of the Seventh schedule to Government of India Act, 1935 were strongly relied on. 1958 SC. 560 at p. 569 regarding the interpretation to be placed on the expression "sale of goods" occurring in entry 48 of List II of the Seventh schedule to Government of India Act, 1935 were strongly relied on. According to counsel, the legislative practice relating to the topics of motor vehicles taxation has to be gathered from the provisions of the Madras Motor Vehicles Taxation Act, 1931 and the Travancore-Cochin Vehicles Taxation Act, 1950. Counsel also referred me to the provisions of the Tolls Act (VIII of 1951) to show that in its origin the levy was in the nature of a compensatory toll. 6. Where the legislature has expressed itself in clear and unambiguous language the function of the court is only to give effect to the plain words used in the statute giving them their ordinary grammatical construction. It is only in cases where there is ambiguity or doubt regarding the meaning or scope of the words used by the legislature that the court is called upon to resort to a process of interpretation seeking the assistance of extrinsic aids such as reference to established legislative practice and other equally well known relevant considerations. 7. It is seen from the preamble to the Act that the object of the legislature in enacting this statute was not merely to unify but also to amend the laws relating to the levy of tax on motor vehicles in the State of Kerala. It will not, therefore, be correct to assume that the legislature intended to impose only a tax identical in its structure and field of operation with the tax previously levied under the Travancore-Cochin Vehicles Taxation Act, 1950 and the Madras Motor Vehicles Taxation Act, 1931. On the other hand, the language of S.3 of the Act shows that there has been a deliberate departure by the legislature from the policy previously followed by it of restricting the tax liability only to vehicles using public roads. A charge to tax is imposed by S.3 on all motor vehicles kept for use in the State quite irrespective of any question as to whether or not or they are used on public roads. In the face of this clear provision it is not possible to accept the petitioners' contention that the legislature must be taken to have intended to levy such tax only on motor vehicles using public roads. 8. In the face of this clear provision it is not possible to accept the petitioners' contention that the legislature must be taken to have intended to levy such tax only on motor vehicles using public roads. 8. In the view that I have taken regarding the interpretation and scope of S.3(1) of the Act the only further question that arises for consideration relating to the validity of the levy is whether the legislature is not legally competent to levy such tax. A reference to entry 57 of List II in the seventh schedule of the Constitution shows that the legislature is duly empowered to levy tax on vehicles, whether mechanically propelled or not, suitable for use on roads including tramcars subject to the provisions of entry 35 of List III. It is therefore clear that the Constitution has not subjected the State's power to impose tax on vehicles to any conditioner limitation that such power shall be exercisable only in respect of vehicles used on public roads. The only test that is required to be satisfied under entry 57 is the test of suitability of the vehicle for use on roads. There being no case for the petitioners that the vehicles are not suitable for use on roads, it cannot be successfully contended that the legislature has no power to impose tax on such vehicles under entry 57 of List II in the seventh schedule. 9. From the above discussion the conclusion must follow that under S.3 (1) of the Act, tax is leviable by the State in respect of all motor vehicles used or kept for use in the State quite irrespective of whether or not such vehicles are used on public roads and that the only exceptions are cases of vehicles coming within the scope of the proviso to S.3(1) or of S.S. 20 and 22 of the Act. 10. Although the petitioners had a case that their vehicles are entitled to exemption under S.20 of the Act the claim has been rejected by the Regional Transport Officer on the ground that the vehicles in question are not used solely for agricultural operations relating to food crops. No grounds have been made out for interference under Art.226 of the Constitution with this finding of fact recorded by the Officer. 11. No grounds have been made out for interference under Art.226 of the Constitution with this finding of fact recorded by the Officer. 11. In the result, the original petitions are dismissed but in the circumstances I do not make any direction regarding costs. Dismissed.