396 



Pa rt III. — Eleventh Annual Report 



The mean temperature of the sea in 1892 was considerably below that in 

 1891, being from a degree* to a degree and a half (Oxcar) lower on the 

 East Coast and from half a degree to a degree lower on the West Coast. 

 Now at all the East Coast stations the mean annual temperature for 

 1891 was from 0° to 0 J, o lower than in 1890, with the exception of 

 Oxcar, where the mean temperature was nearly a degree higher. The 

 two West Coast stations where observations were made in 1890 also 

 show a lower mean for 1891 than for the previous year, although in the 

 case of Brodick the difference is less than the apparent one, since the 

 1890 mean is obtained from only nine months' observations. 



The means for the past three years are arranged in the following 

 table :— 



Mean Temperature of Surface Water for Year. 



Station. 



1892. 



1891. 



1890. 



Fore- 

 noon. 



After- 

 noon. 



Fore- 

 noon. 



After- 

 noon. 



Fore- 

 noon. 



After- 

 noon. 



East Coast. 















Bell Rock, . 



7°7 



7°8 



8-6 



8°7 



o 



9-0 



9°2 



North Carr, 



7'4 



7-5 



8'5 



87 



8-9 



9-0 



Abertay, 



7-5 



7'6 



8-3 



87 



8-9 



9-0 



Oxcar, 



7-6 



7 9 



9-0 



9-6 



[ 8-0 



8-4 



West Coast. 















Stranraer, . 



8-4 





9-3 









West Loch Tarbert, . 





9 '-4 





9-9 







Ardrishaig . 



8-8 



9-0 



9 2 



9-5 



9-4 



9 : 8 



Brodick, 



87* 



9-1* 



9-3* 



9 7* 



9-8t, 



10-3t 



* Taken an hour later than at other stations. t Mean for nine months only. 



The water at the surface of the sea round the Scottish coasts, so far as 

 can be deduced from the limited number of Stations where observations 

 are made for the Fishery Board, was warmer on the whole in 1890 than in 

 1891, and in 1891 showed a notably higher mean temperature than in 

 1892. 



It would be very important to ascertain the relative productiveness of 

 the fishing of these three years, especially as regards the districts where 

 physical observations are made. 



In comparing the results obtained from the various stations it must be 

 remembered that the East Coast observations are not made near the shore, 

 except at Dunbar, but in deep water — either from a lightship (Abertay 

 and North Carr), or from a rock rising sharply up to the surface (Bell 

 Rock and Oxcar). On the West Coast the observations are made from 

 piers or in shallow water, and the temperatures are therefore those of com- 

 paratively shallow shore water. 



At stations where the temperatures of surface and of bottom waters are 

 noted it is found that the upper layers of water are warmer during the early 

 months of the year, and the lower layers are warmer in autumn, except 

 at Stranraer where the bottom "water is usually at a higher temperature 

 than the surface water. 



The mean annual temperature at most stations is the same as that of 

 May and of November, being reached earlier in these months at Oxcar, 

 Abertay, and Ardrishaig, and later at North Carr, Bell Rock, and Brodick, 



* Temperature in this report is given throughout in degrees centigrade. 



