1871-74 Great Northern Telegraph Company 25c. grey, $1 orange-yellow, $3 green & $10 rose-lilac, sets of 4 both of imperf plate proofs, & of the perf 11½ stamps. Imperf 25c with 'Serie F' serial no, the other imperfs w/o serial nos, while the perf stamps all with 'Serie F' serial nos. Hiscocks 1-4 & 1a-4a, Bft 1-4 & 1a-4a. (These stamps were printed by Waterlow & depict Professor H.C. Orsted, the Danish pioneer of electromagnetism. They were prepared for use on the Great Northern Telegraph Company's telegraph network in eastern Asia which had installed telegraph lines Hong Kong – Amoy – Shanghai – Nagasaki). Superb condition, imperfs UN as made, perf stamps MNH with pristine never hinged original gum, both sets right marginal. Of the imperfs probably 2 sheets of 25 of each existed, of which only 1 of the 25c had the serial nos. While of the issued perf stamps only 1 set of sheets of 25 has ever been recorded in private hands from which these originate - & we have never seen any of the issued perf stamps ever offered for sale elsewhere, while the 1 set we had previously had sold for $3700 in our auction 340. Extremely important offering for either the Hong Kong or Chinese specialist, or the collector of world telegraphs. 2018 Ceremuga photo certs. (8) (P)