In Ireland the attempt to bring, into cultivation the immense tracts of bogs or flats partially covered with water, a few years ago attracted the public attention ; and a board of commissioners was appointed to inquire into the nature and extcnt of the bogs in Ireland, and the practicability of reclaiming them.
These commissioners have published reports containing much interesting and instructive matter, exhibiting, the present state of the wastes in certain and evincing clearly the practicability of converting them at a compara tively small expense, into rich arable and pasture land.
On the north and west coasts of Ireland there are a great number of deep bays or inlets of the sea, presenting great facilities fur embanking. Amongst these the estuaries called Lough Swilly and Lough Foyle, in the counties of Donegal and Derry, seemed to offer tosome enterprising speeu lators a tract of land peculiarly adapted for embanking.
Sir John :Macneill having been consulted on the scheme for the drainage of these loughs, employed Mr.J. W. Bazal zette to make the necessary surveys for the purpose, and the latter has furnished to the Institution of Civil Engineers a valuable paper on the subject from which the following observations have been extracted.
Lough Foyle is described by Mr.13azalzette. as not entirely insulated from the Irish Channel, but as having a narrow mouth communicating with it. Above this mouth the waters spread over a wide tract of land, and then again contract into a narrow channel. The edict of the tide rising through so small a passage has been to scour the narrows, and throw up the deposits on the sides of the Lough. By the accumu lations of years these deposits have at last become immense banks of rich alluvial soil extending fifr some miles and covered only at high water. To reclaim this land it was proposed to construct an embankment or sea-wall, a little low-water for film-teen miles in length, by which about 25.000 acres of land would be enclosed.
Lough Swilly is less extensive than Lough Foyle, but pre sents greater difficulty in the construction of the works, frotn the scarcity of the necessary materials. It is wider at its Mouth (w bleb opens into the Western Ocean,) than in any ' other part, mid in its whole extent is extremely exposed to the winds. It was proposed to constrnet here three embank
ments, the first 1,100 yards, the second 1,1:13 yards, and the third 033 yards in length. The position of these hanks being fixed ht careful measurements and soundings, the pro posed method of thrmation was as follows : Each bank was to be 4 feet in perpendicular height above the highest spring-tides, which here rise to IS feet : and to have a slope on the sea-thee of :1 to 1, except in the most exposed part, \ here the slope was to be 4 to 1. The materials aNailable for the WO tit were stone, elay, earth and gravel, taken front the adjoining lands, and the banks were to he faced with rough stones on both sides, laid as close as possible with the edge outwards, in courses not exceeding 4 feet in height. In the centre of each hank was to be built a culvert of masonry, with proper sluices and flood-gates. These culverts were to rest on a finindation made by driving piles into the which from its alluvial character could not be depended upon in itself. '1'lle sluices being sell acting. the d rainage would be efreeted in the following manner. At high water, it being supposed that the whole of the slob (as it is termed in Irebuid,) is covered on the receding of the tidal water, the sluices would shot of themselves, retaining the water within the banks. When the Illtod-tide came on, the pressure on the sluice-gates from within, would prevent their opening, to admit IS, and the retained water would soon eynpo, ate, leaving the rich slob dry, and to lie in a short time lit for agricultural purposes.
The extent of the slid, thin enclosed by these three walls would he about *2,000 acres, and the value of it may be estimated by the thet that a large quantity of lam I has already been reclaimed near this part of the Longh. 'Ilk land now lets at .C5 per acre, mid is considered the richest soil in the neighbourhood. Indeed, in every case, where a proper selection of land has been made. and the works performed judiciously, xnnrhar success has been the result.