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[Then follows a particular description, with measurements in cubic yards and superficial feet respectively, of the various cuttings, embankments, bridges, tunnels, and other works of the canal.]

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"Our whole expense, act, surveys, &c., will be about "10,000l. spent. I have surveyed, levelled, planned, staked "out, and measured the cube yards cut, of the whole, per"sonally; I have also made bargains, superintended the work "and accounts, and by myself and one clerk paid the cash. "I have to the bargain been obliged to oversee every piece "of work that was in the least out of the common road. "I am now, in spite of a most [inclement] season, from "five to six hours in the fields every day, and ride about "ten miles. This is the one side. On the other, I am extremely indolent, cannot force workmen to do their duty, "have been cheated by undertakers and clerks, and am un"lucky enough to know it. The work done is slovenly, our "workmen are bad, and I am not sufficiently strict. I am 'happy in the friendship of the principal residing proprietors, " and am welcome to their houses as to my own, otherwise "my wretched health could not have borne the fatigues I "have undergone. What provokes me most is, that I am "sensible that most people could in the same time have done "much more and better work, possibly with as little trouble "to themselves. I would rather face a loaded cannon than "settle an account or make a bargain. In short I find my"self out of my sphere when I have anything to do with "mankind; it is enough for an engineer to force Nature, and "to bear the vexation of her getting the better of him. Give "me a survey to make, and I think you will have credit of me; I can draw tolerably; set me to contrive a machine, " and I will exert myself; in whatever way you choose to employ me, I shall endeavour to follow your advice."

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For two years and a half, from June, 1770, to December, 1772, Mr. Watt filled his office of engineer to the Monkland Canal, at his salary of 2007. per annum; which he considered a liberal allowance, and which he only resigned on the completion of that work, and his increasing engagements in other

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business of a similar kind. It was in the course of his correspondence in regard to these canals, that Dr. Small having mentioned the desire which Mr. Boulton and he entertained of moving canal-boats by the steam-engine, (which they at first proposed should be on the high-pressure principle) :-" Have you," says Mr. Watt in his reply, "ever considered A SPIRAL "OAR for that purpose, or are you for "two wheels?" And, to make his meaning quite plain, he accompanies his question by this rough sketch of A SCREW PROPELLER: even in the number of turns of the spiral not differing very greatly from such as in our own days, from a wide range of the most careful experiments, have been found to be best fitted for the purpose. The accompanying woodcut gives a faithful facsimile of the remarkable passage in which this idea was started, and which so well deserves to be considered as adding another laurel to those which already adorn the name of Watt.

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Unfortunately for the success of the project at that time, Dr. Small in his reply observed,-"I have tried models "of spiral oars, and have found them "all inferior to oars of either of the "other forms; I believe, because a cy"linder of water immersed in water can "be easily turned round its axis. This, "I dare say, you perfectly know, so 66 more need not be written.

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"that spiral oars are but indifferent." Dr. S. appears to have understood the proposal as being for two oars, one on either side of the boat; whereas there can be little doubt that Mr. Watt, from using the singular, "a spiral oar," as opposed to two wheels, as well as from the very distinct explanatory sketch which he added with his pen, intended his propeller to work at the stern, as a boat is sculled by one oar. Thus, however, did it happen, that the project of the screw-propeller, to be worked by his own improved steam-engine, was propounded by James Watt eighty-eight years ago; that, when propounded, it was, by the discouragement of his friend, abandoned, or at least left in retentis; and that only his suggestion of it has remained, to be disentombed at this distance of time, as a fresh instance of his singular ingenuity and foresight, and as one of the greatest curiosities of what may already be termed the traditional history of engineering antiquity!

In 1770, also, he was employed by the Trustees for the Annexed Estates, (or the estates which in Scotland had been forfeited to the Crown by the attainder of their owners for participation in the rebellions of 1715 and 1745), to make a survey for a canal from Perth to Cupar of Angus:-"I wrote "you from Perth," he says to Dr. Roebuck,* " on Sunday "last, since which time I have been close employed viewing "this country and examining which would be the proper "track for the canal, which I begin to survey to-morrow. "You will, perhaps, think a week a long time to look about "one; but it appears possible to make a canal from the hill "of Kinnoul (opposite to Perth) to Forfar, which will meaabove 36 miles, and that without a lock. There is a "great deal of rough ground betwixt Perth and this place, "but from hence to Forfar the ground is as well adapted as "may be expected in any country. This valley of Strath

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more is about 18 computed miles in length and six in "breadth, but not a dead flat, as we imagined; the soil in "general good, and of all kinds, from sand and gravel to

* From Cupar of Angus, 15 April, 1770.

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clay, though I have seen none so strong as the Kerse clay, " and very little of the country so flat. Agriculture is more "advanced here than in some more southern parts of Scot"land. There are some small proprietors of land, but it mostly belongs to great lords. There is here a great spirit "of improvement; and great abundance of shell marl, but no fuel, except what is brought from Dundee over hills. I have had my health very well here, though "much fatigued, and sometimes very cold with the piercing "winds from the snowy Grampians that form the north side " of this valley."

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My stay in Strathmore," he continues,* "was much longer than I expected. I had to examine and survey a "country of 36 miles in length, and to hunt about for a course "for a canal through country where Nature had almost done. "her utmost to prevent it;-indifferent health, and weather viciously cold and stormy, were the attendants on my "survey. The winds from the snowy Grampians, and snow " even in the valleys a foot thick on the 10th of May, con"vinced me of the utility of what I was about ;-for nothing can be more dismal than such weather in a country which "nature and art have deprived of fuel.”

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And, thirty-six years later, in answer to the Earl of Breadalbane, who, as chairman of a Committee for making a navigable communication between the Tay and Loch Earn, had applied to Government for part of the balances remaining from the forfeited estates, on the ground that such a grant had been in contemplation by the Board of Annexed Estates, and was prevented from being carried into effect only by the dissolution of the board on the restoration of those estates, he wrote,+-"I never made a survey from the Tay to Crieff and Loch Earn; but, at the desire of some "gentlemen of that neighbourhood, I rode over the ground "from the Linn of Campsie to Crieff, when I was making a survey from Perth to Forfar, (I think at the expense of the "Trustees for Fisheries and Manufactures), and found that a

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*To Dr. Small, 9 September, 1770.

† 12 May, 1806.

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"canal in that line was apparently very practicable; but it "has occurred to me since, that the proper line of canal "would be up the valley of Strathearn, from near the con"fluence of the Earn with the Tay; as it would by that means extend its influence over a greater tract of fertile country, and avoid the banks of the Tay, which, as far as "I remember, are in many places very steep between Perth "and the Linn of Campsie. But, as this view was taken so long ago as the year 1770, my memory upon the subject "cannot be much depended upon."

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In the same year, 1770, in which he made his survey in Strathmore, Mr. Watt made a survey, and drew out regulations for the contractor, for building a bridge over the Clyde at Hamilton:-" I have lately made a plan and estimate of a bridge over our river Clyde, eight miles above this; it is to "be of five arches and 220 feet water-way, founded upon "piles on a muddy bottom." He also made a survey and report on the declivities and state of the bed of that river, by desire of the magistrates of Glasgow, who were then engaged in endeavours to improve its navigation and deepen its channel; endeavours which have ever since been strenuously sustained, and have met with well-deserved though then quite unexpected success.

The names of the other engineers with whose Reports on the same subject that of Watt has thus been associated, viz. Smeaton, Golborne, Rennie, Whidbey, Clark, Hartley, and Walker, bear conspicuous testimony to the advancement which Mr. Watt was now rapidly attaining in such pursuits, as well as to the clear-sighted discernment and public spirit of those who thus employed him. The progressive and extraordinary increase of the opulence and commercial consequence of Glasgow as a port, has most signally manifested the advantage of such engineering operations, when conceived with sagacity, directed by a spirit of liberality, and executed with energetic vigour. Of this, no stronger proof can be given, than the fact that whereas in 1770 and eighteen

*To Dr. Small, 21 December, 1770.

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