A HISTORY OF DEVONSHIRE 



Torbay is surrounded with rocks, with one or two sandy beaches, of 

 which the largest is Paignton Sands. The bottom deposit in the bay is 

 chiefly mud, with sand on the south side, and a few patches of rock, chief 

 amongst which may be mentioned the ' Rough ' off Elbury Cove. 



In Teignmouth Bay the bottom deposits are sand inshore, down to 

 5fms., outside this in ii-i2fms., mud, with large stones and shells. 



In the estuary of the Exe low water exposes very large areas of mud, 

 sand, and muddy gravel banks, with Uha and occasional patches of Zostera, 

 of which the largest is ' Greenlands,' situated high up the estuary ; the Zostera, 

 however, is very stunted in growth compared with that found at Salcombe and 

 in the Yealm. The Polesands, a large sandbank on the south side of the 

 mouth of the estuary, consist of fine sand on the sea side, and coarse loose 

 sand on the north side. 



The conditions prevailing in the estuary of the Teign are somewhat 

 similar to those in the Exe. Both have a particularly strong tide, which is 

 said to run at 5 knots at Exmouth during spring tides. 



On the north coast the shore is chiefly rocky, with a few sandy beaches, 

 chief amongst which are those in Barnstaple and Morte Bays. The only 

 important estuaries are those of the Taw and Torridge, both of which have 

 a common outlet in Barnstaple Bay. 



The bottom deposits in deeper water are no less varied. Mud is found 

 in the east end of Start Bay, and from Berry Head to Teignmouth it extends 

 in a south-east direction for 10-15 niiles. With these exceptions most of 

 the trawling grounds are of fine or coarse sand, with areas of various grades 

 of gravel and stones, and an occasional outcrop of rock, especially close in 

 shore. Of the rocky patches may be mentioned the Mewstone Ledge, off 

 Yealm Head, the Eddystone Reef, the ledge in Teignmouth Bay, and the 

 ' Rough ' off Torcross. 



Tidal differences are naturally of great importance to the shore collector. 

 On the south coast they vary from 1 8 ft. at springs and 1 1 ft. at neaps at 

 Plymouth to 12 and 8 J ft. respectively at Exmouth. 



The strength of the tidal currents in the estuaries is about 5 knots at 

 spring tides at Exmouth and Teignmouth, 3 knots at Salcombe, and 1-3 in 

 Plymouth Sound, whilst in the offshore area it varies between i and 2 knots. 



According to Matthews^ the water in the channel during 1903 was 

 derived chiefly from the Bay of Biscay in February and May, from the Irish 

 Sea in August, and from both sources in November, its salinity varying 

 between 35-26 and 35*49. Dickson^ gives the following as the mean 

 monthly temperature of the surface of the sea at Salcombe, based on daily 

 temperatures taken by the coastguards during 17 years, 1880-86, 1888-97. 



Deg. Fahr. Deg. Fahr. 



January 45-4 July ^8-6 



February 45-3 August 597 



March 45-7 September 59-1 



April 48-1 October 55-4 



May 52-0 November 51-9 



June 56-2 December 48-0 



Year : — 52"i deg. Fahr. 



1 North Sea Fisheries Investigation Committee, Report 2, Southern Area. 



' The Mean Temperature of the Surface Waters of the Sea round the British Coast and its Relation to the Mean 

 Temperature of the Air (Q.T.R. Met. Soc. xxv.). 



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