Dulat, J.

1. This writ petition (No. 287 of 1956) was referred to this Bench by Bishan Narain, J., on the view that it sought to challenge the vires of East Punjab General Sales Tax Act, 1948. Before us, however, it emerges from the arguments that what is in substantial dispute is not the validity of the Act but the application of that Act to the particular facts of the present case and the main controversy actually is about the facts themselves.

2. The petitioners are timber merchants of Yamunanagar in the Ambala district although the head offices of some of the petitioners are outside the Punjab. The petitioners are being assessed to sales tax under the East Punjab General Sales Tax Act, 1948, and they claim exemption in respect of certain sales of timber made by them to the Railway Department, and the exemption is claimed on the ground that those particular sales took place outside the State of Punjab and are consequently not hit by the Sales Tax Act. Only in the alternative it is suggested that if the East Punjab General Sales Tax Act purports to impose a tax on such sales made outside the State, then it is invalid as the State Legislature has no authority to impose suc