from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A turbulent section of a body of water, caused by strong currents passing over submerged ridges.
- v. To fall over (something).
- v. To attack (someone).
- v. To fall over.
from the GNU version of the Collaborative International Dictionary of English
- n. A cataract; a waterfall.
- n. A turbulent surface of water, caused by strong currents setting over submerged ridges; also, a dangerous submerged ridge or shoal.
from The Century Dictionary and Cyclopedia
- n. A cataract; the fall of a river; a rapid.
- n. Nautical: A dangerous bank or shoal lying near the surface of the sea.
- n. A rippling or race in the sea, where, by the peculiarities of the bottom, the water is propelled with great force, especially when the wind and tide or current set strongly together.
- Overshot, as a water-wheel.
- n. Nautical:
- n. A sudden drop in the sea-bottom, as at the edge of a submarine terrace or ledge.
- n. That portion of a dam or weir over which the water falls or flows, including the crest and the down-stream face of the dam.
- To fall over: as, a fog overfell them.
- To fall upon; to attack.
- To fall; fall over.
They continued then to follow the shores of Lake Grant by climbing the plateau; but, after having gone a mile in this direction, Cyrus Harding had not been able to discover the overfall, which, however, must exist somewhere.
If h '0 and if there is a limiting depth tlimit above the weir crest, the overfall is submerged.
The DAM at the Croton River is 40 feet high, and the overfall 251 feet in length.
At seven-thirty o'clock, he was again lost sight of in a heavy overfall, the current setting to the eastward at a place commonly known as La Ballesta.
On September 18 they put into the excellent port of the island of Gomera, 'the best,' he says, 'in all the Canaries, the town and castle standing on the very breach of the sea, but the billows do so tumble and overfall that it is impossible to land upon any part of the strand but by swimming, saving in a cove under steep rocks, where they can pass towards the town but one after the other.'
Between Dawney and Beta lieth a famous island in Orenoque (now called Baraquan, for above Meta it is not known by the name of Orenoque) which is called Athule (cataract of Ature); beyond which ships of burden cannot pass by reason of a most forcible overfall, and current of water; but in the eddy all smaller vessels may be drawn even to Peru itself.
It was most probable that an overfall existed somewhere, and doubtless through a cleft in the granite.
Harding had not been able to discover the overfall, which, however, must exist somewhere.
Thus the course of calculation and the formulas to be applied are the same for the retaining weir in the river and the free overfall weir in the lateral intake, e.g. between forebay and diversion canal (Fig. 26).
Numerical examples of the calculation of a free and submerged overfall weir as well as an overfall over a weir with stilling basin or race floor are given in Annexes 3 to 5.