a river of Ireland, by far the largest in that country, and one of the most important in the United Kingdom. Its source is at the foot of Caileagh, one of the mountains in the county of Cavan, which surround Lough Allen, into which it falls after a course of a few miles. Out of this lake, which is about 10 miles in length, it issues at its southern extremity, and flows in an irregular course, generally southwards, in a narrow, shallow, and somewhat interrupted bed. It receives the Boyle River from Lough Key on the right, and further down it expands into a sheet of water called Lough Bodrarrig. Beyond this it flows through a wide expanse of boggy land, till it enters the northern extremity of Lough Ree at Lanesborough. This lake is the second in size of those the Shannon flows through, being 17 miles in length by 7 in its greatest breadth. It is diversified by many promontories, bays, and creeks, and has very beautiful scenery. Issuing from Lough Ree, a little above Athlone, the Shannon continues to pursue a circuitous and southerly course, through a low, flat, and fertile region, dividing itself at some places into arms which enclose considerable islands. In this part of its course, the Suck, its chief affluent, and little inferior to the main river, joins the Shannon from the west, after a course of 60 miles.

The largest lake that the river flows through is Lough Derg; it is 25 miles long, narrow, and much indented. It is also the most beautiful in its scenery; for, unlike the others which lie in low ground, a great portion of this lake, especially its lower end, is environed by mountains; Slievy Boughty rising on the west, and the Arra Mountains on the east. From Killaloe at the foot of Lough Derg, the Shannon flows south-west to Limerick; and about half-way between these places are the falls of Doonass. These are, properly speaking, rapids; the river, which is here 40 feet deep and 300 yards broad, rolling tumultuously over a succession of rugged rocks for about half a mile, in the midst of luxuriant meadows and shaggy woods; while the ruins of Castle Connel occupy a lofty rock overlooking the stream.

From Limerick onwards the course of the Shannon is due west, and it is here rather an estuary or arm of the sea than a river, though it is known by the name of the Lower Shannon. It enters the Atlantic between Lough Head on the north, and Kerry Head on the south. Several rivers join it in this part of its course, the chief of which is the Fergus, from the north. The whole length of the Shannon, from its source to the sea, is 220 miles. During its course from Lough Allen to below Lough Bodarrig it separates the counties of Leitrim and Roscommon; from thence to the lower part of Lough Derg it divides Leinster and Munster on the one side, from Connaught on the other; Longford, Westmeath, and King's County belonging to the first, Tipperary to the second, Roscommon and Galway to the third of these provinces. The rest of its course lies in Munster, between Clare on the 'north', Limerick and Kerry on the south. The most remarkable thing about the Shannon is the length of navigable water it has. In this respect it is far superior to any river in the United Kingdom, for vessels may ascend from its mouth as far as Lough Allen, so that there are only 6 or 7 miles out of 220 that cannot be navigated. There are, indeed, at various places obstructions caused by the shoals and rapids of the river; but these have, for the most part, been overcome by lateral canals, or by deepening the channel. Upwards of half a million sterling has been expended on various works for the improvement of the river; and yet, from the want of proper management, it is still in an unsatisfactory state. The value of such a river to the country is necessarily very great, as it connects the most inland places with the sea, and by the Grand and Royal Canals to Dublin inland navigation is extended also to other parts of the island. The highest tides in the Shannon rise about 18 feet, the lowest 14; the velocity in narrow parts of the estuary is frequently very great, and the water assumes an appearance very like that of a bore. Several varieties of fish are found in the Shannon, and the most productive fishery is that of eels.