Shackleton's 1908 Expedition: cover addressed to 'Mr T.D. Robertson / King Edward VII Land / South Pole', endorsed at top left 'per Nimrod', dated at lower left '29-11-08', franked with ½d pair with Invercargill machine cancel, with 2 line violet h/stamp 'Not Known At / King Ed-VII Land'. Plus 3 transit cancels on the reverse and octagonal 'Christchurch / Unclaimed' on the front