June, 1834. erratic blocks, 289 



strongly prove it than La Condamine's* story. He says, 

 " Below Borja even for four or five hundred leagues, a stone, 

 even a single flint, is as great a rarity as a diamond would 

 be. The savages of those countries don't know what a stone 

 is, and have not even a notion of it. It is diversion enough 

 to see some of them when they come to Borja, and first meet 

 with stones, express their admiration at them with signs, and 

 be eager to pick them up, loading themselves therewith as 

 with a valuable merchandise." It is therefore a remarkable 

 circumstance that as soon as we reach the colder latitudes in 

 the southern hemisphere (from 41° to Cape Horn), the same 

 phenomenon occurs, almost on as grand a scale and with 

 similar limits, as in the northern parts both of the Old and 

 New World. Neither in the southern nor in the northern 

 hemisphere do the fragments, coming from the polar regions, 

 or from other mountain groups, arrive within a considerable 

 distance of the lines of the tropics. 



We must couple the absence of erratic blocks along that 

 part of the Andes which is situated under a warmer climate, 

 with the similar non-occurrence, as I am informed by Pro- 

 fessor Royle, in Northern India round the flanks of the 

 Himmalaya ; — those loftiest pinnacles on the face of the globe. 

 With regard to Southern Africa, from lat. 35° to the tropic. 

 Dr. Andrew Smith, who has visited as a naturalist so large a 

 portion of the interior, assures me he has never seen any 

 thing of the kind. Nor do I recollect meeting with any 

 mention of them, in the w^orks of the numerous travellers in 

 the equatorial regions of the same continent. The same 

 remark certainly holds good with Australia in the parallel of 

 Sydney, but perhaps is more doubtful with respect to Van 

 Diemen's Land.f To my mind these negative facts| have 



* La Condamine's Voyage (English translation), p. 24. 



-|- I will here put together all the (apparent?) exceptions which I have 

 met with to the supposed law that erratic blocks are absent in the inter- 

 tropical regions of the world. First, iii the Bulletin de la Societc Geo- 

 logique, 1837, p. 234, there is an account of some erratic blocks near 

 Macao (lat. 22" N.) ; but as it is distinctly stated they are all of granite, 

 VOL. in. u 



