The scientific world will warmly welcome the foundation of the Institute of Navigation, and indeed we may regret that it was not founded long ago. The interest in scientific navigation goes back nearly 300 years, since it was with the aim of assisting navigation that the Royal Observatory was founded, and during the eighteenth century navigation was greatly advanced by the encouragement given to Harrison in his work on the chronometer. It took some time before this was extensively used at sea, but by the beginning of the nineteenth century it would have appeared that astronomical navigation had nearly reached perfection. It was a fine and accurate science, as witnessed by the world surveys made by such seamen as Captain Fitzroy in the 1820's and 1830's, and little more seemed to be called for, or indeed could be expected as long as astronomy was the sole means of location. In the seventeenth and eighteenth centuries our Institute would have had a great many interesting activities, but in the nineteenth we cannot help feeling it would have been rather dull. Even then, however, there is a matter that may excite our surprise, for the ‘Sumner’ line was discovered at a rather late date, by a master mariner at sea, whereas it ought to have been an obvious idea to anyone with even a rudimentary mathematical training.