BHAGWATI, J. :- These three appeals involve common questions of law and the facts in all the three appeals are also similar barring difference only in the period in respect of which octroi duty has been claimed by the Kadi Municipality (hereinafter referred to as the Municipality) and paid by the New Chhotalal Mills Company Limited (hereinafter referred to as the Company) and the amount of such octroi duty and it would therefore be sufficient if only the facts of the first appeal are set out in full and a mere reference to the period and amount of octroi duty is made in so far as the second and third appeals are concerned. The history of the facts relevant for the purpose of these appeals dates back to 24th June 1933 when the Company purchased a Textile Mill from the Liquidator of the Laxmi Cotton Mills Company Limited at a public auction held by the District Judge, Mehsana. The Textile Mill was situate in Kadi comprised within the territories of the former State of Baroda. After purchasing the Textile Mill the Company started running it from June 1934. It appears that around this time the Company made an application to the Baroda Government for exemption from certain taxes and duties and the Baroda Government by a Tharav dated 16th April 1935 granted those exemptions to the Company. We shall have occasion to examine the true nature and character of this Tharav a little later but it is sufficient to state for the present that one of the exemptions granted by the Tharav was and that is the exemption with which wears primarily concerned in these appeals from octroi duty leviable by the Municipality in respect of goods which might be brought within the mill premises by the Company. The exemption was not a total exemption but was a partial one in that octroi duty was exempted only to the extent to which it exceeded Rs. 300/-. The period for which the exemption was granted was twenty years. It appears that at the date when the Tharav was passed, the mill premises were not within the limits of the Municipality and there was accordingly no octroi duty payable by the Company in respect of goods which might be brought by it within the mill premises. On 11th February 1937, however, a notification was issued by the appropriate authority under the B Class Municipalities Act, being Act No. 32 of Samvat 1983, by which the Municipality was governed extending the limits of the Municipality so as to include within those limits the land on which the mill was situate. The mill premises having been brought within the limits of the Municipality, the Company became liable to pay octroi duty to the Municipality in respect of goods brought by it within the mil! premises. In view, however, of the exemption granted to the Company, the liability of the Company to pay octroi duty to the Municipality was limited to Rs. 300/- per year and the Company accordingly did not pay any amount exceeding Rs. 300/- per year as and by way of octroi duty to the Municipality. In 1939 the B Class Municipalities Act, being Act No. 32 of Samvat 1983 was repealed and substituted by the B Class Municipalities Act, being Act No. 14 of 1949, but the exemption granted to the 'Company continue and the Company continued to pay not more than Rs. 300/- per year in respect of octroi duty to the Municipality. This state of affairs continued right upto 1st May 1949 when the Ruler of Baroda State ceded full and exclusive authority, jurisdiction and powers for and in relation to the governance of the Baroda State to the Government of India under a merger agreement entered into between him and the Government of India. The territories of the Baroda State were thereafter governed by the Government of Bombay in virtue of the power delegated to it by the Central Government under S. 3(2) of the Extra-Provincial Jurisdiction Act, 1947, until the passing of the States Merger (Governors' Provinces) Order, 1949, by which the territories of the Baroda State became part of the territories