Lord Diplock (delivering judgment of the Board):

This appeal from the Federal Court of Malaysia is about the right to mine tin in an area of land near Papan Town in the State of Perak, and, in particular, in what was formerly part of the Railway Reserve for the Ipoh-Tronoh line. It turns upon the meaning of a forty-year-old agreement dated 22 October 1931. To this agreement there were three parties described as "the company", "the sub-lessee" and "the miner". The company is the appellant in this appeal, the interest of the sub-lessee in the agreement has devolved upon the second respondent and the interest of the miner is represented in this appeal by the first respondent as a consequence of events which it is no longer necessary to canvass in order to dispose of the appeal. Their Lordships will adopt the expressions "the company", the "sub-lessee" and "the miner", as referring also to those persons by whom the corresponding interest of the original party to the agreement was from time to time represented.

At all material times mining lands in Perak have been vested in the Sultan and the working of minerals regulated by the Mining Enactment. This provided for the grant of