[Illustration: SALVAGE VESSELS OFF YARMOUTH, ISLE OF WIGHT] XIII THE SALVAGE SECTION THE TIDEMASTERS IF Royal Canute, King of England and Denmark, with his train of servile earls and thanes, could revisit the scene of his famous object-lesson, he would learn a new value in the tide. Suitably, he might improve his homily by presentation of the salvage tidemasters, harnessing the rise and fall of the stubborn element to serve their needs and heave a foundered vessel to sight and service. He would note the cunning guidance of strain and effort, their exact timing of the ruled and ordered habits of the sea. As a moral, he could quote that, if tide may not be ordered to command, it can at least be governed and impressed to performance of a mighty service. Recovery of ships, their gear and cargo, is no longer wholly an application of practised seamanship. The task is burdened and complicated by powers and conditions that call for auxiliary arts. It is true that the salvage officer's ground, his main asset, is the knowledge and ability to do a seamanlike 'job o' work' when the time and tide are opportune; he must have a seaman's training in the ways of the wind and the sea and be able properly to assess the weather conditions under which alone his precarious work is possible. A scientist of a liberal and versatile type (not perhaps exhaustive in his scope and range), he is able to draw the quantum of his needs from a wide and varied summary. Together with his medical exemplar, he has developed a technique from crude remedies and imperfect diagnoses to application of fine science. He must have a sure knowledge of the anatomy of his great steel patients, be versed in the infinite variety and intricacy of ship construction, and the valves and arteries of their power; be able to pen and plan his formulæ for weight-lifting--the stress and strain of it, down to the calibre of the weakest link. A super-tidesman, he must know to an inch the run of bottom, the swirl and eddy, the value of flood and ebb and springs, for the tide--Canute's immutable recalcitrant--is his greatest assistant, a familiar _Genius maris_ whom he conjures from the deeps of ocean to do his bidding. Shrewd! He is a keen student of the psychology of the distressed mariner; again, like the medical man, he must set himself to extract truth from the tale that is told. His treatment must be prescribed, not to meet a case as presented, but as his skilled knowledge of the probabilities warrants. Tactful, if he is to meet with assistance in his difficult work, he must assume the sympathy of one seaman to another in distress. What, after all, does it matter if he agree heartily that "the touch was very light, we were going dead slow," when, from his divers' reports, he knows that the whole bottom is 'up'?