FORTH, (including the arm of the sea generally called the Frith of Forth,) is the name of the largest river of Scot land, and that which has the longest course, rising on the north side of the mountain Ben Lomond, and discharging itself into the German Ocean in 55° 5 4' of North Latitude. The Forth, near its source, receives a small stream, and is then called Avondow, or the Black River ; and, on enter ing the parish of Port, receives the name of Forth, which is said to signify the same. Soon afterwards into a beautiful lake, from whence it is precipitated over a per pendicular rock, 30 feet high, and flows with a smooth winding course from Gartmore to Stirling bridge, 33 miles, though only 20 in a direct line. Thence, having received a considerable accession in the waters of the rivers Teith, Allan, and Doran, it gradually enlarges to 4 miles in width at Borrowstounness, but exhibits the most singular and beautiful sinuositics in traversing a level plain, called the Cruse of Stirling, where 24 miles occupied by its channel are no more than 6 miles in a straight line by land. It is next narrowed to less than two miles, by the sudden pro jections of headlands from the two Queensferries on its opposite sides, below which a regular expansion, little in terrupted, (the Bodotria of the Romans, and now named Frith of Forth,) is resumed down to Fifeness on the north, and St Abbs Head on the south, where it meets the German Ocean. Between these two points the distance is between 35 and 40 miles. The direct course of this river is scarcely less than 100 miles ; but its sinuosities do not traverse a shorter space than 200. Its depth from Sterling bridge to the mouth is from 3 to 37 fathoms, or more ; between Inch Garvie and the North Ferty it is 35 ; and somewhat further west, opposite to Rosyth castle, whet e the breadth is 3000 yards, it is 21 fathoms, whence it gradually shallows up wards. Part of the bottom is here covered with sleech or mud, 20 feet deep, deposited on freestone. The tide flows a mile above Sterling bridge, or between 70 and 80 from the sea in a straight line, until it is interrupted by a rock across the channel, where stream tides rise live feet. It flows and ebbs regularly twice in twenty-four hours ; but the flood and ebb run about two hours' longer in the middle than along the shore, and it rises at most about four fathoms in a stream. Besides this, however, there are particular cur rents, or irregularities, above Queensferry, and particularly from Culross to Alloa, or, beginning at the mouth of the river Carron and Borrowstounness, continue downwards. These irregularities consist in an intermission of the tide during the flood ; and before high water the sea ebbs. On the contrary, while the sea ebbs, and before low water, the ebb intermits, and a flow commencing continues some time ; after which the ebbing is resumed until low water. This is seen during two hours, and the irregularity occupies more of the river, according as it is spring or neap tide. These irregularties are well known by the name of leakies.
The principal rivers tributary to the Forth are, the Goodie, rising in the Loch of Monteith, the Teith and Allan, above Sterling bridge ; and below it, the Dovan, Carron, Avon, Almond, Leith, Esk, Leven, Tyne, and others. There is, besides, a communication, by means of a navigable canal, with the river Clyde, which preserves an intercourse be tween the east and west coasts of Scotland.
It would take a long time to describe the natural pro ductions of the Forth, and hitherto they have met with very little attention. Various cetacea, from 20 to 60 feet in
length, migrate here from the northern seas ; and whole shoals of grampuses have accidentally stranded themselves on the shores. We learn from history, that five or six hundred years ago they also frequented this river. The porpoise is constantly seen tumbling in the water ; one specimen of the beluga, or white whale, was killed in 1815, near Stirling : the sun fish is occasionally taken ; and the opah, or gold fish, has also occurred. But there are others, the constant source of valuable and productive fisheries ; • such as salmon, herring, haddock, turbot, and oysters. A great salmon fishery is carried on at Stirling, which sup plies all the neighbourhood, and allows a quantity for ex port. Salmon is so abundant, and so easily obtained at this part of the Forth, that the inhabitants of Stirling were, dur ing a long time, provided with it at the rate of three half pence a pound, which became a particular privilege, nor is it long since it was abrogated. Two fisheries on a smaller scale have recently been established on the south side of the river, at Abercorn, and near Queensferry, and their produce chiefly transmitted to the capital ; and a third was attempted near the first, which had sonic success, at Black ness castle. Vast shoals of herring resort periodically to the Forth, and afford employment to many hands in their capture, as well as ample subsistence to the poor ; but they are neither so large nor so much esteemed as those taken on the west coasts of Scotland. Nevertheless, their cheap ness, which is sometimes sixpence a hundred, is of incal culable benefit to a large city, where there arc many indi gent inhabitants, as well as to the towns on the coast, which in general possess little wealth. The herring fishery, which has rather declined of late from the uncertainty of success, is carried on from the mouth of the river to six or eight miles above Queensferry. Haddock, cod, and turbot fisheries, are principally lower down than Leith. Skate, flounders, and halibut, are common ; turbot is obtained in sufficient quantity to supply Edinburgh market at prices not immoderate, that is, from four to ten shillings, accord ing to size and scarcity ; but most of it goes to London. Some time ago, contracts were made for turbot, at two shillings each when taken, to be carried thither. Soles also inhabit the sandy bays of Aberlady and Musselburgh, but are seldom caught. This being ascribed to the unskilful ness of the fishermen, an experiment was made by others purposely brought from places noted for it ; but, after re peated trials, the fishery was given up. To judge by the shells thrown up on the coast, an extensive portion of the Frith is inhabited by oysters; and, accordingly, many valuable oyster beds are resorted to, for the most part to the east ward of Leith. There is little doubt, however, that there are others for several miles westward of it. Great quanti ties of oysters are consumed ; for it is a favourite kind of food, both in the sea-port towns and in the country ; and there are particular rules observed in dredging, and in re jecting those of insufficient size. The beds themselves belong to different private proprietors ; but some have been totally exhausted from injudicious management. The con sumption of oysters is so great in the metropolis, that there are certain regulations established for conducting the mar ket. Mussels are also collected in quantities along the shores ; and while oysters are sold by numbers, they are sold by measure, at so much per pint.