38 Fishery Board for /Scotland. 



of 0°, but rather to the fact that m this region the temperatures of 

 our standard meridian were unduly depressed by proximity to the 

 great cold land-mass of Iceland ; (3) the very marked lowering of the 

 minimal temperatures, especially in the southern half of the diagram, 

 that is to say, where the line passes through the North Sea. 



There are many other matters connected with the surface tem- 

 perature phenomena of our seas, and many other facts contained in 

 our tables and our diagrams, which might be dwelt upon at much 

 greater length and further illustrated in various ways. For instance, 

 I have not attempted to describe, or to discuss in words the various 

 special phenomena which, at various seasons, characterise one portion 

 or another of our coasts. These various phenomena will, for the most 

 part, be obvious enough to any careful student of our charts. It will 

 be time enough for a more detailed discussion when our observations 

 have become more numerous, and all our facts are better established. 

 Let me remark, in conclusion, that, while all the charts and diagrams 

 in this paper are to be regarded as no more than first approximations 

 to the truth, drawn to the best of my own powers from the somewhat 

 scanty data which are all that we have as yet, this is especially true 

 of the isopleth diagrams (Figs. 25-32) which we have just been dis- 

 cussing. These are to be clearly understood as diagrammatic or 

 simplified representations of much more complicated phenomena. 

 As a matter of fact, these isopleth diagrams were all drawn before I 

 made my last revision of the maps on which they are based, and to 

 embody our last corrections in them would have involved redrawing 

 the whole series. None of the corrections are such as to interfere 

 with the general truth of the diagrammatic picture ; but it is possible 

 that a careful reader may here and there discover some slight 

 discrepancy between these diagrams and the isotherms of our twelve 

 monthly charts. 



