288 Apparent objections to the Glacial Theory. 



power of diffusing large blocks over northern tracts, yet such, 

 with reference to the period of deposition, are geologically distinct 

 from those other blocks and detritus more properly termed 

 erratics ; and again such modern blocks become more numerous to- 

 wards the lower limit of icebergs than in the preceding part of their 

 course. 



Now it ought naturally to follow, that if icebergs were the agents 

 which scattered the true erratics and detritus, the occurrence of 

 such phenomena should be more frequent as we approach the 

 southern limit to which icebergs are supposed to have travelled, 

 than when we journey northwards ; for as the icefloes engendered 

 in the north, sailed down towards the south, the higher tempera- 

 ture towards which they were floating would have caused them 

 to deposit the detritus with which they were charged over those 

 tracts within the influence of tropical heat, and consequently a far 

 greater accumulation of blocks and detritus would be found in those 

 warm southern regions over which the icebergs had melted, than in 

 those cold climates of the north which had given them birth. We 

 should therefore look for such transported matter in abundance as 

 we neared the warmer regions, and in a decreasing ratio as we tra- 

 velled north to the countries from whence the icebergs and boulders 

 started. But is such the fact ? assuredly not, — for precisely the 

 very reverse is well known to be the case, and Lyell himself, the 

 propounder of the theory, tells us, that " these erratics are far more 

 numerous in northern countries, although some are met with as far 

 south as the Swiss Jura;" (LyelVs Elem. Geol. p. 136, J and it 

 is precisely the gradual diminution of these blocks both in size and 

 frequency as we proceed southwards, which has hitherto influenced 

 all observers in declaring the course of the last diluvial currents to 

 have been from north to south. In this respect, therefore, the or- 

 der of deposition apparent in recent and ancient erratics is reversed, 

 and the inferences deduced cannot be relied on, for while modern 

 deposits of transported matter increase as we travel from the north 

 towards the limits to which icebergs can attain, the ancient detri- 

 tus is found on the contrary to decrease ; thus in this instance 

 it is evident, that the causes now in operation did not produce the 

 effects under consideration. 



