152 IV. CLIMATE. 



that for the whole twenty-four hours, at some neigh- 

 bouring place, becomes the corrected mean temperature. 



Unfortunately, when brought togethei", many of those 

 records ai'e scarcely to be reconciled one with another. 

 Some years are rather colder or rather warmer than the 

 average for a series ; and it is seldom possible to compare 

 the same number and series of j'^ears for many different 

 places. Instruments differ in their graduation, one com- 

 pared with another. The situations in which they are 

 fixed, are not always the best adapted for giving true 

 indications at all times and seasons. And observers are 

 themselves more or less inexact ; besides having to ap- 

 point deputies to obseiwe for them during occasional 

 absence. The chances and sources of error become 

 altogether somewhat numerous ; although several of them 

 may tend to neutralize each other in the averages, by 

 leading to some figures being given in excess, while 

 others are given in deficiency. 



This is not the place or opportunity to write an essay 

 on thermometrical registration. Tables of recorded tem- 

 perature may be found in pubHshed works on meteoro- 

 logy, physical geographj'-, phyto-geogi'aphy, &c. Some 

 such tables relating to the climate of this country were 

 introduced into the little work published by the same 

 writer full twenty years ago, under title of ' Remarks on 

 the Geographical Distribution of British Plants.' After 

 the lapse of a score of years those tables might now be 

 greatly extended and improved. But it is feared that if 

 thus re-written and enlarged, and accompanied by suf- 

 ficiently ample explanations and needful qualifications, 

 they might become too far lengthened in proportion to 

 the pages that could be spared for them here. And at 

 last, they would still be only a collection of details and 

 almost unconnected facts. Instead, an attempt will now 



