Far more interesting is an account we obtained of the Caledonian Canal, which may truly be said to make an island of Sutherland, Caithness, Cromarty, Rosshire, and a part of Inverness.  The canal was designed by Watt, as far back as 1773; but the present work was not commenced until the year 1804, when Telford was directed to make a report on the subject.  By his plan the canal was to be one hundred and ten feet wide at the surface and fifty feet at the bottom, and the depth of water twenty feet; so that a thirty-two gun frigate of that day, fully equipped and laden with stores, could pass through it.  The works, however, were carried out on more moderate proportions.  There are twenty-eight locks, each one hundred and seventy feet long and forty feet wide, with an average lift of eight feet.  Some of the lock gates are of timber, and others are of cast-iron, sheathed with pine planking. The summit level is in Loch Oich, into which pour a number of streams, supplying an abundance of water for both sides.  It stands exactly one hundred feet above high-water mark at Inverness.  The extreme length from sea to sea is sixty and a half miles; and so direct is the continuity of the lakes that a line drawn across from point to point would only exceed the distance by rather more than three miles.  There are twenty-two miles of canal cutting, and thirty-eight and a half miles of lake water is made available for the canal.