Leaky Tides at Kennetpans
The tides in the River Forth, for several miles, both above and before Clackmannan, exhibit a phenomenon not to be found (it is said) in any other part of the globe. This is what the sailors call a leaky tide, which happens always in good weather during the neap tides; and sometimes also during the spring tides, if the weather be uncommonly fine. When the water has flowed for 3 hours, it then turns back for about an hour and a half, exactly as far as when it began to flow; it returns immediately; and flows during another hour and a half to the same height it was before; and this change takes place both in the flood and the ebb tides. So that there are actually double the number of tides in this river that are to be found anywhere else. In very boisterous weather, however, these leaky tides are by no means regular; but water only swells and gorges, without any perceptible current, as if the two tides were acting against each other. The cause of this irregular phenomenon in the tides of the river Forth may be a subject of inquiry to the philosopher; for it has not as yet been discovered.