Dr Martens on the Glaciers of Spitsbergen. 177 



of the blocks are thrown off at the sides, and form the lateral 

 moraines which accompany the glaciers. 



5 th, During the two voyages of the Recherche, we never saw 

 blocks transported by floating ice ; but in crossing Bell Sound, 

 a little before entering the bay, my colleague M. E. Robert 

 has seen floating ice stained with earth on the surface, which 

 at the moment was taken for sandbanks. 



Thick ness of Glaciers.- — The lowest part of the glaciers 

 of Spitsbergen, that which looks to the sea, always forms a 

 vertical wall, the height of which varies between 30 and 

 120 metres. That of the glacier of Horn Sound, measured 

 geometrically by Scoresby,* was 121 metres. The second 

 of the glaciers of Smeerenberg or Fairhaven, 91 metres, ac- 

 cording to Phipps.t At Magdalena Bay, the glacier of TEn- 

 tre'e was 63 metres : that of Pointe aux Tombeaux, 76 metres, 

 according to the measurement of the officers of our vessel who 

 had charge of the hydrographical department. I estimate 

 that of the two glaciers, which terminate the two bays, at 32 

 metres. 



In Lapland, the great mass of ice which cover's the Sulitel- 

 ma presents an escarpment of 65 metres in height at its lower 

 part.:}: In Switzerland, the inferior glaciers in general are only 

 from 10 to 25 metres in thickness. § However, the Oberaar- 

 gletscher is 32 metres at its foot ;|| the Unteraargletscher, 38 

 metres \% that of Aletsch, scarcely 30 metres, near the lake 

 M$;-ill ;** that of Bois from 25 to 30 metres.ft 



But the thickness of the upper glaciers, HugiJt thinks, must 

 be estimated, at an average, from 40 to 60 metres. We thus 

 see that the resemblance between the Mers de Glace of Spitz- 

 bergen and the upper glaciers of Switzerland is supported 

 even by numerical calculations. 



{To be concluded in next Number.) 



* L. c. p. 102. t A Voyage towards the North Tole, p. !'<>. 



% Wahlenberg, 1. r. § 13. § Hftgi, 1. <•. p. :s: J .0. || Ibid. p. 17«. 



« ; [bid. p. 331. ** Ibid. ibid. U De Saasstee, 1. c. § 523. 



: <•. p. 33& 



VOL. SXX. 10. MX. JAM VliV lfi-lJ. M 



