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riting to another of the family： ‘I am sorry you took the trouble of applying to me about your son； as it lies quite out of my way to forward his views in the line of his profession as a Draper。'
III
A professional life of Robert Stevenson has been already given to the world by his son David； and to that I would refer those interested in such matters。 But my own design； which is to represent the man； would be very ill carried out if I suffered myself or my reader to forget that he was； first of all and last of all； an engineer。 His chief claim to the style of a mechanical inventor is on account of the Jib or Balance Crane of the Bell Rock； which are beautiful contrivances。 But the great merit of this engineer was not in the field of engines。 He was above all things a projector of works in the face of nature； and a modifier of nature itself。 A road to be made； a tower to be built； a harbour to be constructed； a river to be trained and guided in its channel … these were the problems with which his mind was continually occupied； and for these and similar ends he travelled the world for more than half a century； like an artist； note…book in hand。
He once stood and looked on at the emptying of a certain oil…tube； he did so watch in hand； and accurately timed the operation； and in so doing offered the perfect type of his profession。 The fact acquired might never be of use： it was acquired： another link in the world's huge chain of processes was brought down to figures and placed at the service of the engineer。 ‘The very term mensuration sounds ENGINEER…LIKE；' I find him writing； and in truth what the engineer most properly deals with is that which can be measured； weighed； and numbered。 The time of any operation in hours and minutes； its cost in pounds； shillings； and pence； the strain upon a given point in foot…pounds … these are his conquests； with which he must continually furnish his mind； and which； after he has acquired them； he must continually apply and exercise。 They must be not only entries in note…books； to be hurriedly consulted； in the actor's phrase； he must be STALE in them； in a word of my grandfather's； they must be ‘fixed in the mind like the ten fingers and ten toes。'
These are the certainties of the engineer； so far he finds a solid footing and clear views。 But the province of formulas and constants is restricted。 Even the mechanical engineer comes at last to an end of his figures； and must stand up； a practical man； face to face with the discrepancies of nature and the hiatuses of theory。 After the machine is finished； and the steam turned on； the next is to drive it； and experience and an exquisite sympathy must teach him where a weight should be applied or a nut loosened。 With the civil engineer； more properly so called （if anything can be proper with this awkward coinage）； the obligation starts with the beginning。 He is always the practical man。 The rains； the winds and the waves； the complexity and the fitfulness of nature； are always before him。 He has to deal with the unpredictable； with those forces （in Smeaton's phrase） that ‘are subject to no calculation'； and still he must predict； still calculate them； at his peril。 His work is not yet in being； and he must foresee its influence： how it shall deflect the tide； exaggerate the waves； dam back the rain…water； or attract the thunderbolt。 He visits a piece of sea…board； and from the inclination and soil of the beach； from the weeds and shell…fish； from the configuration of the coast and the depth of soundings outside； he must deduce what magnitude of waves is to be looked for。 He visits a river； its summer water babbling on shallows； and he must not only read； in a thousand indications； the measure of winter freshets； but be able to predict the violence of occasional great floods。 Nay； and more； he must not only consider that which is； but that which may be。 Thus I find my grandfather writing； in a report on the North Esk Bridge： ‘A less waterway might have sufficed； but the VALLEYS MAY COME TO BE MELIORATED BY DRAINAGE。' One field drained after another through all that confluence of vales； and we come to a time when they shall precipitate by so much a more copious and transient flood； as the gush of the flowing drain…pipe is superior to the leakage of a peat。
It is plain there is here but a restricted use for formulas。 In this sort of practice； the engineer has need of some transcendental sense。 Smeaton； the pioneer； bade him obey his ‘feelings'； my father； that ‘power of estimating obscure forces which supplies a coefficient of its own to every rule。' The rules must be everywhere indeed； but they must everywhere be modified by this transcendental coefficient； everywhere bent to the impression of the trained eye and the FEELINGS of the engineer。 A sentiment of physical laws and of the scale of nature； which shall have been strong in the beginning and progressively fortified by observation； must be his guide in the last recourse。 I had the most opportunity to observe my father。 He would pass hours on the beach； brooding over the waves； counting them； noting their least deflection； noting when they broke。 On Tweedside； or by Lyne or Manor； we have spent together whole afternoons； to me； at the time； extremely wearisome； to him； as I am now sorry to think； bitterly mortifying。 The river was to me a pretty and various spectacle； I could not see … I could not be made to see … it otherwise。 To my father it was a chequer…board of lively forces； which he traced from pool to shallow with minute appreciation and enduring interest。 'That bank was being under…cut；' he might say。 ‘Why？ Suppose you were to put a groin out here； would not the FILUM FLUMINIS be cast abruptly off across the channel？ and where would it impinge upon the other shore？ and what would be the result？ Or suppose you were to blast that boulder； what would happen？ Follow it … use the eyes God has given you … can you not see that a great deal of land would be reclaimed upon this side？' It was to me like school in holidays； but to him； until I had worn him out with my invincible triviality； a delight。 Thus he pored over the engineer's voluminous handy…book of nature； thus must； too； have pored my grand…father and uncles。
But it is of the essence of this knowledge； or this knack of mind； to be largely incommunicable。 ‘It cannot be imparted to another；' says my father。 The verbal casting…net is thrown in vain over these evanescent； inferential relations。 Hence the insignificance of much engineering literature。 So far as the science can be reduced to formulas or diagrams； the book is to the point； so far as the art depends on intimate study of the ways of nature； the author's words will too often be found vapid。 This fact … that engineering looks one way； and literature another … was what my grand…father overlooked。 All his life long； his pen was in his hand； piling up a treasury of knowledge； preparing himself against all possible contingencies。 Scarce anything fell under his notice but he perceived in it some relation to his work； and chronicled it in the pages of his journal in his always lucid； but sometimes inexact and wordy； style。 The Tr