Or when impenetrable fog envelops them for days at a time, rendering chart and reckoning worthless, the as surance that a practically continuous line of keen-eyed and sleepless senti nels march and countermarch along the surf-beaten beaches or stand guard with warning signals in hand upon the jutting cliffs and headlands reaching far out into the sea for unwary vic tims, lends a comfortable sense of se curity. That this confidence is not misplaced is attested by the statistics of the Service, which show that of more than a hundred thousand lives imperiled upon vessels wrecked or in distress within the scope of the opera tions of the station crews since the systematic organization of the Service in 1871, less than one per cent has.