‘A cetacean of the northern, the far northern seas, a moderate whale of about five yards long; and the male possesses a horn that may be half as long again. I say “horn” sir, because that is the term commonly used; but in fact the object is made of ivory.’
‘And only the males wear it?’
‘So I am told by whalers and by those few who have had the happiness of dissecting the creature.’
‘Then they share our fate: for with us too it is the males alone that wear the horns.’ After a moment Mr Wright began to laugh - a low, creaking sound that went on and on. ‘Forgive me,’ he said at last, taking off his spectacles and wiping them. ‘I am facetious at times. You were speaking of ivory?’
‘Yes, sir: a particularly hard and dense ivory. The infant narwhal has but two teeth, both in his upper jaw. That on the right usually remains in a rudimentary state: the other develops into a tapering column that may protrude for six or seven feet and weigh a stone or more.’
‘What is its function?’
‘That appears to be unknown. There are no reports of its use as a weapon - no boat has ever been attacked - and although sportive narwhals have been seen to cross their tusks above the surface, no fighting ensued, and it was thought to be done in play. As for its alleged use as a fishspear, an animal with no hands would be puzzled to transfer its transfixed prey from tusk to mouth: besides, the females are tuskiess: yet they do not starve. There are innumerable suppositions, all based upon very little knowledge indeed; but there is one undoubted, instantly observable phenomenon - the very curious shape of the horn. Not only does it bear a large number of parallel spirals ascending in half a dozen left-hand turns from the base almost to the bare, smooth tip, but it also has several much larger tori or undulating turns, rising in the same direction. All this puzzles me extremely, though I am something of a physiologist, devoted to comparative osteology; and I should very much like to ask whether these adaptations of the tusk are designed to strengthen it, without adding to its already considerable bulk, and whether the much larger tori help the animal, a very rapid swimmer, to diminish the turbulence it must encounter at every stroke. I am aware sir, that turbulence is one of the chief studies among gentlemen of your profession.’
‘Turbulence. Aye, turbulence,’ said Mr Wright, shaking his head. ‘Any man that means to build a lighthouse, or a bridge, or a jetty, must think long and hard upon turbulence, and the enormous force exerted by water in violent motion. But oh the wearisome calculations, the uncertainty! On the face of it, sir, your suppositions seem reasonable: surface corrugation does often increase resistance to certain forms of stress; and conceivably your tori might have a favourable effect in directing a spiral flow past the advancing body and in counteracting the rotary force - for your animal is propelled by his tail, is he not?’
‘Just so. A horizontal tail, of course, like the rest of his kind.’
‘It is an interesting problem: but any suggestion that I might put forward, based solely on a verbal description, however well-informed, would scarcely be worth the air expended. If I could see the horn, measure the depth and angle of the spiral and of the larger processes, my opinion might possibly have some slight value.’
‘Sir,’ said Dr Maturin, ‘if you would honour me with your company at dinner, let us say tomorrow, I should be delighted to show you my tusk, a small but perfect specimen.’
Jack and Stephen met again, almost on the very steps of the Crown. ‘Well met, brother,’ cried Jack from a little distance. Stephen considered the Commodore’s face and his gait: was he sober? ‘You look uncommon cheerful, my dear,’ he said, leading him in the direction of the Pigtail Steps. ‘I wish you may not have met with some compliant young person, overwhelmed with all the gold lace upon your person.’
‘Never in life,’ said Jack. ‘Aubrey the Chaste is what I am called throughout the service. I did indeed meet a young person, but one that shaves, when he can afford it. Stephen, you may remember that I have told you about our grievous lack of master’s mates, and how I yearned to replace poor Wantage?’
‘I do not suppose you have mentioned it much above ten times a day.’
‘It is not a question of those midshipmen who are promoted master’s mate merely so that they may pass for lieutenants at the end of their servitude - you know of course that they have to show certificates proving that they have served in that rating for two years - no, no, it is your true master’s mate, the mate to the master of the ship, if you follow me, whose only ambition is to become a master himself, an expert navigator and ship-handler, but as an officer with a warrant from the Navy Board rather than the King’s commission. Admittedly we have Salmon, but how I longed for another, if only to second poor tired old Woodbine! Our mids are good young fellows, but they are not mathematicians, and their navigation is brutish, brutish.’
A vigilant eye aboard Surprise had caught the Commodore’s broad gestures, designed to illustrate the brutishness of the ordinary midshipman’s navigation, and his boat set off across the harbour at once. It took some time to thread its way through the crowded shipping and smallcraft - the whole squadron was refitting at the utmost speed - and Jack went on, ‘Well, the young person I met was John Daniel.’ He looked into
