Lord Macmillan.-

The appellants are the owners of a private radio station, originally designated by the letters C K G W, at Bowmanville, some forty miles from Toronto, which they began to operate in 1928. In 1933, the Canadian Radio Broadcasting Commission, constituted under the Canadian Radio Broadcasting Act, 1932, who were then organizing a basic network of stations across Canada, entered into negotiations with the appellants with a view to acquiring a lease of their undertaking. As a result of these negotiations the appellants and the Commission on 9th and 16th June 1933, executed an indenture of lease "as of" 15th May 1933. It is with the chequered fortunes of this lease that the present litigation is concerned. Its validity, its interpretation and its effect are all in issue.

[2] The subjects of the demise are described as consisting of the lands and premises of the appellants at Bowmanville and "all plant and equipment owned by the lessor and used by it in connection with the operation of radio broadcasting station C K G W, the whole of the said property being hereinafter referred to as the 'demised premises.'" The lease in cl. 2 is expressed to be "for and during the terms of