On the other side of the river there exists a natural ridge, which is a little higher than the highest floods. It is not continuous, but interrupted in five places. These circumstances are held by Mr. Lynam to “render it very easy to protect the lowlands from all floods.” Very favourable sites exist for back-drains to carry off rain-water and springs. The 641 acres of lowlands may be thus protected from summer and autumn floods at a cost of 6000_l._, being 10_l._ per acre. This would allow of winter irrigation also, which the occupiers of the lands particularly require. The system of river embankments is much objected to as dangerous, and properly so, when it is proposed to make high embankments. In this case the required embankments are in existence for seven-eighths of the required length, so permanently solid as to be absolutely safe, and the small portions to be built need not be more than 3 feet to 5 feet high. The obstructions are a rock-shoal near the middle of the length, an old bridge with narrow arches and thick piers, and a shoal of solid limestone rock at the outlet. MINOR IRISH RIVERS. _The Barrow River_ has been rendered navigable from the tideway below St. Mallins up to where it is joined by the Grand Canal at Athy Bridge, a distance of 43 miles, falling 172 feet. But from Athy to the mouth of the Barrow, in the estuary of Waterford Harbour, and through that to St. George’s Channel, the distance exceeds 60 miles. _The Blackwater River_, county Cork, is navigable from its mouth at Youghall up as far as the tide reaches, or at most to Cappoquin. There is another, and smaller Blackwater, connected with the Tyrone Canal, and flowing into Lough Neagh. _The Boyne River_ is navigable from the Bay of Drogheda for 22 miles, up to Trim, in the last 7 miles of which it ascends from Navan 189 feet by means of locks, which are from 80 to 100 feet long and 15 feet wide. _The Corrib River and Lough_, or Lake, form a navigable line, commencing at the mouth of that river, in Galway Bay, and extending from Galway town in a north-westerly direction for about 24 miles. _The Earne River and Lough_, or Lake, are navigable through the lake from the upper part, where the river enters it, below Belturbet, till it leaves it again at Enniskillen, where it is obstructed by weirs; but below the isle on which that town is built the river again expands into the lower part of the lake, through which it is also navigable. Thus far the entire distance is about 30 miles, and the navigation is terminated by a fall, from which the river has a rapid course of 9 miles to Donegal Bay. It has been proposed to construct a canal from Lough Earne, beginning near Belturbet, and to follow along the valleys of the Finn and Blackwater to Lough Neagh. _The Fergus River_, county Clare, is navigable from its mouth, in the Shannon, up to Ennis, the county town.