This extraordinary pass has excited public attention ever sidce the tirne of the Romans. In the curious map by Richard of Cirencester, (composed in the fourteenth century, and founded chiefly on Ptolemy's Tables,) a continued canal is represented along the whole of the valley between the east and West Seas. Of this, per haps the most ancient of existing maps, a correct copy is inserted in the able mernoir which accompanies Mr. Arrowsmith's excellent map of Scotland.
'Fire magnificent remains of Urquhart Castle on the east, and those of Inverlochy Castle on the west, with the chain of vitrified signal forts along the valleys, and likewise the three modern forts, are satisfactory evidence of its having constantly formed an important political feature in the country. After having long been subser N lent to the purposes of contention and warfare, it oc curred to their last agents, that it was at least equally well adapted for commercial intercourse, and the object, supplying the wants of the garrison at Fort Augustus, contributed to an experiment of navigating the largest lake. The importance of a general intercourse became, at last, so manifest, that in 1773, the trustees for the for feited estates employed IVIr. James Watt, (the celebrated improver of the steam engine,) then resident at Glasgow, to make a survey, and report respecting the practicabili ty of connecting the lakes and forming an inland naviga tion. This able and enlightened person, having made the necessary surveys with his usual accuracy, gave a description of the valley ; and stated that the regularity of this extensive track, in such a rugged country, was truly astonishing, and that the whole, as well as the com munications with the respective seas, were particularly favourable for an Inland Navigation.
The forfeited estates being restored to the respective families, the office of trustees was of course abolished, and any project which ntight have resulted from the above-mentioned survey was lost.
From this time the subject lay dormant until 1802, when, during the administration of Mr. Addington (now Lord Siclmouth) the state of warfare in the northern parts of Europe, the best mode of promoting the fisheries on the coasts of Scotland, and the local events of the north ern portion of the kingdom, having become objects of serious consideration, the lords of the treasury employed Thonias Telford, civil engineer, to make surveys of the whole coasts or Scotland, and also the interior of the northern counties, to report their present state, and his opinion as to various modes of improvement, The re sults of his extensive surveys and reports went to the establishing naval stations, improving ports, superseding ferries, by opening the country by means of roads and bridges, and consttucting an inland navigation across the great glen of Scotland, which he designatcd thc CALE DONIAN CANAL.
These eports appeared so important to the treasury board, and more especially to Mr. Nicholas Vansittart, who was then Secretary, and since Chancellor of the Exchequer, that the whole was immediately referred to a special committee of the Iiouse of Commons, who, af ter investigating the several subjects and examining evi dence upon all the material points, recommended, that the whole should be carried into effect ; parliament also approved of the plan, and two Boards were established under two separate acts, viz. one for constructing and im proving harbours, and making roads and bridges; and the other for constructing the CALEDONLAN CANAL. These Boards have ever since been assiduously employ ed upon the objects committed to their charge, and these objects have been nearly all successfully accomplished.
Considering the facilities afforded by (he lakes, and that it was desirable to accommodate the trade between the western parts of England and Scotland, and all Ire land ; the eastern coast of Britain, the Baltic, and East Country ; and also between the east coast of Scotland and the West Indies, and likewise to pass small ships of war ; Mr. Telford recommended, and the Board adopted, a ca nal upon a large scale, viz. 120 feet wide at the water surface, 50 feet at the bottom, and 20 feet depth of water : the locks of 170 and 180 feet of length, and 40 feet wide ; these dimensions being sufficient, both in single and unit ed locks, to admit of the largest vessels trading between Liverpool and the Baltic, the average of West lndiamen, and a 32 gun frigate when fully equipped. It likewise appeared, by the evidence of commercial and seafaring men, that if a navigation upon this scale was accom plished, the frequent and serious losses sustained in na vigating by the Orkneys and Cape Wrath, (luring the autumn, winter, and spring months, would be avoided ; that it would at all times be much more direct, and that it would be particularly useful in the time of war.