From the Strand, May 1899:

Our next photograph is a facsimile of an address on a letter that found its way from Spain to the G.P.O., St. Martin’s-le-Grand. Remarkable as it may seem, this specimen of handwriting was deciphered by ‘the blind man of St. Martin’s,’ and the letter safely reached its destination. It is addressed to the ‘Spanish Ambassador (or Embassy), London.’

(The “blind men” were “the decipherers of illegible and imperfect addresses” in the returned letter office of the General Post Office. Further examples.)