8. The Government of India Act, 1919, which, among other things, aimed at giving a reasonable measure of autonomy to the provinces as the first step in the process of self-government, made the first clear-cut allocation of resources between the Centre and the provinces without having any divided heads between them. Under this Act, certain specific heads were given wholly to the provinces and the remaining sources were retained by the Centre. Thus among the principal heads of revenue, Land Revenue, Excise and Stamps were given to the provinces, while the Centre retained Customs, Income-tax, Salt and Opium. Of the three great commercial departments of Government, Railways and Posts and Telegraphs were retained by the Centre, while Irrigation was handed over to the provinces,