{"article":{"id":"britannica-11-english-chakkel","work_id":"britannica-11","title":"English Chakkel","normalized_title":"english-chakkel","slug":"english-chakkel","aliases":[],"subtitle":"Internet Archive OCR import","body_text":"ENGLISH CHAKKEL (commonly called \"The Channel\"; Fr. La Uanche, \" the sleeve \"), the narrow sea separating England from France. If its entrance be taken to lie between Ushant and the Scilly Isles, its extreme breadth (between those points) is about 100 m., and its length about 350. At the Strait of Dover, its breadth decreases to 20 m. Along both coasts of the Channel, cliffs and lowland alternate, and the geological affinities between successive opposite stretches are well marked, as between the Devonian and granitic rocks of Cornwall and Brittany, the Jurassic of Portland and Calvados, and the Cretaceous of the Pays de Caux and the Isle of Wight and the Sussex coast, as well as either shore of the Strait of Dover. The English Channel is of comparatively recent geological formation. The land-connexion between England and the continent was not finally severed until the latter part of the Pleistocene period. The Channel covers what was previously a wide valley, and may be described now as a headless gulf. The action of waves and currents, both destructive and constructive, is well seen at many points; thus Shakespeare Cliff at Dover is said to have been cut back more than a mile during the Christian era, and the cliffs of Grisnez have similarly receded. Of the opposite process notable examples are the building of the pebbly beaches of Chesil Bank and near Treguier in C6tes du Nord, and the promontory of Dungeness. The total drainage area of the English rivers flowing into the Channel is about 8000 sq. m.; of the French rivers, including as they do the Seine, it is about 41,000 sq. m. From the Strait of Dover the bottom slopes fairly regularly down to the western entrance of the Channel, the average depths ranging from 20 to 30 fathoms in the Strait to 60 fathoms at the entrance. An exception to this condition, however, is found in Kurd's Deep, a narrow depression about 70 m. long, lying north and north-west of the Channel Islands, and at its nearest point to them only 5 m. distant from their outlying rocks, the Casquets. Towards its eastern end Hurd's Deep has an extreme depth of 94 fathoms, and in it are found steeper slopes from shoal to deep water than elsewhere within the Channel. Nearing the entrance to the Channel from the Atlantic, the 100 fathoms line may be taken to mark the edge of soundings. Beyond this depth the bottom falls away rapidly. The too fathoms line is laid down about 180 m. W. to 120 m. S.W. of the Scilly Isles, and 80 m. W. of Ushant. Within it there are considerable irregularities of the bottom; thus a succession of narrow ridges running N.E. and S.W. occurs west of the Scillies, while only 4 m. N.W. of Ushant there is a small depression in which a depth of 105 fathoms has been found. As a general rule the slope from the English coast to the deepest parts of the Channel is more regular than that from the French coast, and for that reason, and in consideration of the greater dangers to navigation towards the French shore, the fairway is taken to lie between 12 and 24 m. from the principal promontories of the English shore, as far up-channel as Beachy Head. These promontories (the Lizard, Start Point, Portland Bill, St Alban's Head, St Catherine's Point of the Isle of Wight, Selsey Bill, Beachy Head, Dungeness, the South Foreland) demarcate a series of bays roughly of sickle-shape, the shores of which run north and south, or nearly so, at their western sides, turn eastward somewhat abruptly at their heads, and then trend more gently towards the south-east. On the French coast the arrangement is similar but reversed; Capes Grisnez, Antifer and La Hague, and the Pointe du Sillon demarcating a series of bays (larger than those on the English coast) whose shores run north and south on the eastern side, and have a gentler trend westward from the head. The configuration of the coasts is perhaps the chief cause of the peculiarities of tides in the Channel. From the entrance as far as Portland Bill the time of high water is found to be progressively later in passing from west to east, being influenced by the oceanic tidal stream from the west under conditions which are on the whole normal. But eastward of a line between Portland Bill and the Gulf of St Male these conditions are changed and great ' irregularities are observed. On the English coast between Portland Bill and Selsey a double tide is found. At Portland this double tide corresponds approximately with the time of low water in the regular tidal progression, and the result is the occurrence of two periods of low water, separated by a slight rise known locally as \" gulder.\" But farther east the double tide corresponds more nearly with the time of high water, and in consequence either the effect is produced of a prolonged period of high water, or there are actually two periods of high water, as at Southampton. Various causes apparently contribute to this phenomenon. The configuration of the coast line is such as to present at intervals barriers to the regular movement of the tidal wave (west to east), so that reflex waves (east to west) are set up. In the extreme case at Southampton the tidal effect is carried from the outer Channel first by way of","body_html":"

ENGLISH CHAKKEL (commonly called "The Channel"; Fr. La Uanche, " the sleeve "), the narrow sea separating England from France. If its entrance be taken to lie between Ushant and the Scilly Isles, its extreme breadth (between those points) is about 100 m., and its length about 350. At the Strait of Dover, its breadth decreases to 20 m. Along both coasts of the Channel, cliffs and lowland alternate, and the geological affinities between successive opposite stretches are well marked, as between the Devonian and granitic rocks of Cornwall and Brittany, the Jurassic of Portland and Calvados, and the Cretaceous of the Pays de Caux and the Isle of Wight and the Sussex coast, as well as either shore of the Strait of Dover. The English Channel is of comparatively recent geological formation. The land-connexion between England and the continent was not finally severed until the latter part of the Pleistocene period. The Channel covers what was previously a wide valley, and may be described now as a headless gulf.

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The action of waves and currents, both destructive and constructive, is well seen at many points; thus Shakespeare Cliff at Dover is said to have been cut back more than a mile during the Christian era, and the cliffs of Grisnez have similarly receded. Of the opposite process notable examples are the building of the pebbly beaches of Chesil Bank and near Treguier in C6tes du Nord, and the promontory of Dungeness. The total drainage area of the English rivers flowing into the Channel is about 8000 sq. m.; of the French rivers, including as they do the Seine, it is about 41,000 sq. m. From the Strait of Dover the bottom slopes fairly regularly down to the western entrance of the Channel, the average depths ranging from 20 to 30 fathoms in the Strait to 60 fathoms at the entrance. An exception to this condition, however, is found in Kurd's Deep, a narrow depression about 70 m. long, lying north and north-west of the Channel Islands, and at its nearest point to them only 5 m. distant from their outlying rocks, the Casquets. Towards its eastern end Hurd's Deep has an extreme depth of 94 fathoms, and in it are found steeper slopes from shoal to deep water than elsewhere within the Channel.

\n

Nearing the entrance to the Channel from the Atlantic, the 100 fathoms line may be taken to mark the edge of soundings. Beyond this depth the bottom falls away rapidly. The too fathoms line is laid down about 180 m. W. to 120 m. S.W. of the Scilly Isles, and 80 m. W. of Ushant. Within it there are considerable irregularities of the bottom; thus a succession of narrow ridges running N.E. and S.W. occurs west of the Scillies, while only 4 m. N.W. of Ushant there is a small depression in which a depth of 105 fathoms has been found. As a general rule the slope from the English coast to the deepest parts of the Channel is more regular than that from the French coast, and for that reason, and in consideration of the greater dangers to navigation towards the French shore, the fairway is taken to lie between 12 and 24 m. from the principal promontories of the English shore, as far up-channel as Beachy Head.

\n

These promontories (the Lizard, Start Point, Portland Bill, St Alban's Head, St Catherine's Point of the Isle of Wight, Selsey Bill, Beachy Head, Dungeness, the South Foreland) demarcate a series of bays roughly of sickle-shape, the shores of which run north and south, or nearly so, at their western sides, turn eastward somewhat abruptly at their heads, and then trend more gently towards the south-east. On the French coast the arrangement is similar but reversed; Capes Grisnez, Antifer and La Hague, and the Pointe du Sillon demarcating a series of bays (larger than those on the English coast) whose shores run north and south on the eastern side, and have a gentler trend westward from the head. The configuration of the coasts is perhaps the chief cause of the peculiarities of tides in the Channel. From the entrance as far as Portland Bill the time of high water is found to be progressively later in passing from west to east, being influenced by the oceanic tidal stream from the west under conditions which are on the whole normal. But eastward of a line between Portland Bill and the Gulf of St Male these conditions are changed and great ' irregularities are observed.

\n

On the English coast between Portland Bill and Selsey a double tide is found. At Portland this double tide corresponds approximately with the time of low water in the regular tidal progression, and the result is the occurrence of two periods of low water, separated by a slight rise known locally as " gulder." But farther east the double tide corresponds more nearly with the time of high water, and in consequence either the effect is produced of a prolonged period of high water, or there are actually two periods of high water, as at Southampton. Various causes apparently contribute to this phenomenon. The configuration of the coast line is such as to present at intervals barriers to the regular movement of the tidal wave (west to east), so that reflex waves (east to west) are set up. In the extreme case at Southampton the tidal effect is carried from the outer Channel first by way of

","volume_id":"britannica-11-v9","page_range_label":"Vol. 9, pp. 455-455","source_url":"https://archive.org/details/encyclopaediabrit09chisrich/page/n502/mode/1up","text_source_url":"https://archive.org/download/encyclopaediabrit09chisrich/encyclopaediabrit09chisrich_djvu.txt","scan_source_url":"https://archive.org/details/encyclopaediabrit09chisrich","quality_status":"ocr-imported-page-aligned","parser_version":"ia-djvu-xml-v1","page_refs":[{"page_number":"455","label":"p. 455","image_url":"/source-assets/scans/britannica-11/encyclopaediabrit09chisrich/encyclopaediabrit09chisrich_0503.jpg","source_image_url":"https://archive.org/download/encyclopaediabrit09chisrich/encyclopaediabrit09chisrich_jp2.zip/encyclopaediabrit09chisrich_jp2%2Fencyclopaediabrit09chisrich_0503.jp2&ext=jpg","source_url":"https://archive.org/details/encyclopaediabrit09chisrich/page/n502/mode/1up"}]},"work":{"id":"britannica-11","slug":"britannica-11","title":"Encyclopaedia Britannica","short_title":"Britannica 11th","edition":"11th edition","publisher":"Cambridge University Press","publication_start_year":1910,"publication_end_year":1911,"language":"English","country":"United Kingdom / United States","copyright_status_note":"First published before 1931; treated as public domain in the United States. Verify jurisdiction before redistribution outside the U.S.","source_quality":"mixed-clean-and-ocr","text_source_url":"https://en.wikisource.org/wiki/1911_Encyclop%C3%A6dia_Britannica","scan_source_url":"https://archive.org/details/encyclopaediabri","volumes":[{"id":"britannica-11-v1","volume_number":"1","title":"A to Androphagi","year":1910,"source_url":"https://archive.org/details/encyclopaediabri01chisrich","text_source_url":"https://en.wikisource.org/wiki/1911_Encyclop%C3%A6dia_Britannica","scan_source_url":"https://archive.org/details/encyclopaediabri01chisrich","page_count":1084},{"id":"britannica-11-v2","volume_number":"2","title":"Andros to Austria","year":1910,"source_url":"https://archive.org/details/encyclopaediabri02chisrich","text_source_url":"https://archive.org/download/encyclopaediabri02chisrich/encyclopaediabri02chisrich_djvu.txt","scan_source_url":"https://archive.org/details/encyclopaediabri02chisrich","page_count":null},{"id":"britannica-11-v9","volume_number":"9","title":"Edwardes to Evangelical Association","year":1910,"source_url":"https://archive.org/details/encyclopaediabrit09chisrich","text_source_url":"https://archive.org/download/encyclopaediabrit09chisrich/encyclopaediabrit09chisrich_djvu.txt","scan_source_url":"https://archive.org/details/encyclopaediabrit09chisrich","page_count":null},{"id":"britannica-11-v26","volume_number":"26","title":"Submarine Mines to Tom-Tom","year":1911,"source_url":"https://archive.org/details/encyclopaediabri26chisrich","text_source_url":"https://archive.org/download/encyclopaediabri26chisrich/encyclopaediabri26chisrich_djvu.txt","scan_source_url":"https://archive.org/details/encyclopaediabri26chisrich","page_count":null},{"id":"britannica-11-v27","volume_number":"27","title":"Tonality to Vesuvius","year":1911,"source_url":"https://archive.org/details/encyclopaediabri27chisrich","text_source_url":"https://ia903207.us.archive.org/15/items/encyclopaediabri27chisrich/encyclopaediabri27chisrich_djvu.txt","scan_source_url":"https://archive.org/details/encyclopaediabri27chisrich","page_count":null}]}}