FORTH, one of the largest rivers in Scotland. It is formed of two streams rising to the north of Ben Lomond, (one of them passing through Loch Chon and Loch Ard), which unite above Aberfoyle. The river flows eastward in a direct course for above 100 miles, receiving in its progress the Goodie, the Teith, and the Allan above Stirling, and below it the Devon, the Carron, the Avon, the Almond, the Leith, the Esk, the Leven, the Tyne, and others; and it discharges itself into the German Ocean in about 56° 10' N. lat. The windings or “links” of the Forth above and below Stirling are extremely tortuous. From its junction with the Teith to the “carse” or alluvial plain below Gartmore they extend about 28 miles, although the distance in a direct line is only about 20. From Stirling harbour to Alloa, where it widens into an estuary, the length of the river is 10 j miles, though the distance in a straight line is not more than 5. From Grangemouth to North Queensferry the depth increases in the first mile from 10 to 15 feet, in the second to 25, and in the third mile to 53 feet, while the remaining part of the distance—7 miles, including the great anchorage of St Margaret’s Hope—has a depth generally of about 60 feet at low water. At Queensferry the firth is 2 miles wide; between Dysart and Aberlady about 12; and between St Abb’s Head and Fifeness, where it joins the German Ocean, it is from 35 to 40 miles. Near Queensferry, between Inchgarvie and the North shore, it deepens to 37 fathoms. The bed of the river consists to a great extent of mud,—the depth of the deposit in some places being upwards of 200 feet; and there are extensive alluvial formations along the lower part of its course, and in the upper reaches of its estuary. The tides are felt 4¾ miles ...