A New Flora of Northumberland and Durham; With Sketches of Its Climate and Physical Geography, with a Map (Paperback)

Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: Mictiu lllil'lil.i-. [i AND DTTBHAH. 51 mean temperature falls as we ascend the hills at the rate of 1 for every 100 yards. For the interior of the country, from London northward to Edinburgh, we may take from 47 to 49 as a fair average, 47 for the South of Scotland, 48 for the North of England, and 49 for the Midland counties: the difference between summer and winter being usually from 18 to 20. On the sea coast the difference between summer and winter is smaller than in the interior, and the mean temperature generally a shade higher; but in our table this last character, as between Bywell and Shields, does not hold good. We will take then the annual average of our Lower zone at from 48 to 45, of the Middle zone at from 45 to 42, and of the Upper one at 40 or 41. The great characteristic of the climate of Britain, as compared with that of other parts of the North Temperate zone, is its equability, the absence of extreme degrees of either heat or cold, and the consequent smallness of the difference there is between winter and summer. "We shall see shortly what an important influence this has upon the distribution of plants. Even within the compass of England we can trace palpably the influence of the sea in cutting off the extremes in both directions. Of course, it is on the west side of the island that this influence operates most powerfully, and we see from the table just given, that although Helston is 6 warmer in winter than Greenwich or York, it is rather colder than the former and only 1J warmer than the latter in summer; at Shields and Alnwick that the difference between summer and winter is only 16 and 14. The winter is not materially colder at Newcastle than at London; but all the other seasons are, though the difference, when expressed in figures, is probably much ...