384 ANTARCTIC VOYAGE OF THE BELGICA. 



Ill the seas navigated by the Belgica we have seen as nianj as 110 

 icebergs at once, distributed all around the horizon. Fort}^ per cent of 

 these would be of the characteristic tabular form, while the remainder 

 resembled arctic bergs, or some form derived from the tabular. Large 

 icebergs were rare; heights of 50 meters (164 feet) were quite excep- 

 tional, and the tabular 1)ergs averaged only 30 to 40 meters (1)8 to 131 

 feet). The tabular icebergs are covered over with neve, and only show 

 the alternate blue and white bands at the base. . I only once had an 

 opportunity of examining this stratification, in an iceberg which was 

 inclosed in the pack and displaced so that the strata dipped at a con- 

 siderable angle. Both the blue and white bands were formed of glacier 

 ice with the characteristic grained structure; the strata were not 

 sharph' separated from one another, the only difference between blue 

 and white being that the ice in the latter was more porous, inclosing a 

 large number of air bubbles; the ice in both was compact. 



The supposition that tabular bergs are formed of sea ice is entirely 

 wrong. The mode of formation of the sea ice shows that its thickness 

 constantly tends to a limit, supposed by Weyprecht*" to be 7 meters 

 (23 feet) at a maximum, however low the mean winter temperature 

 and however great the number of years. I think Weyprecht's limit 

 is too great for the antarctic regions. In any case the continental 

 origin of the antarctic icebergs is indisputable, for the bed of the 

 Antarctic Ocean is covered with terrigenous deposit? and erratic 

 blocks laid down b}^ the melting of the ice, and these materials are 

 transported to great distances from the glaciers from which they are 

 derived. 



Our soundings'' and those of Ross have shown that the continental 

 inland ice does not extend (on the continental shelf) bej'ond the isobath 

 of 400 meters (1,312 feet), and this mav be taken as the maximum total 

 thickness of the icebergs coming from the pole in the whole antarctic 

 area of the Pacific. If one-eighth of the tabular icebergs appear 

 above the surface, we go 50 meters (164 feet) as the limiting height 

 of the bergs detached from the great ice barrier known to extend from 

 Victoria Land to longitude 170° W., and which doubtless continues 

 eastward to the land to south and west of Alexander Land. 



As soon as the Belgica entered the Pacific Ocean, the surveys of 

 the strait discovered being completed, and the season already well 

 advanced, de Gerlache did not wish to lose time, and set his course to 

 the southwest in order to cross the pack which we entered in longitude 

 80° W. Several attempts to penetrate the pack failed. 



In longitude 85°, however, the edge of the pack was more to the 

 south, and on Februar}'^ 27 we reached latitude 70° S. without difficulty, 

 the ice being navigable, and, aided by a gale, we made rapid progress 



*K. Weyprecht, Die Metamorphosen dos Polareises, p. 139. 



••H. Arctowski, The Bathymetrical Relations of the Ajitarctic Regions (CTCOg. 

 Journ., July, 1899). 



