B. TERRESTRIAL PHYSICS AND METEOROLOGY. 107 



in (act, that the rains of the warm months are but slightly, 

 if at all, useful in regulating the flow of the river waters, be- 

 cause of the large evaporation which carries off the greater 

 portion of the rain-fall. Their own observations have, in ad- 

 dition, shown that whenever, toward the end of May, the head- 

 waters of the Seine have been very low, this deficiency is 

 never made up until after the middle of October. The rec- 

 ords of the past one hundred and twenty-five years show 

 that the stage of highest water has varied in the spring-time, 

 between February and March ; and, in general, the relations 

 of the river-flow to the surrounding country are such that 

 while they could not attempt to predict any thing with re- 

 gard to the character of the weather during the coming 

 summer and autumn, they were confident as to the truth of 

 their prediction with regard to the river-flow, and certainly 

 expected that by the middle of October the River Seine 

 would exhibit one of the very lowest stages that has ever 

 been recorded. 6 B, LXXVIII., 1528. 



THE FORMATION OF ICEBERGS. 



On the formation of icebergs, G. C. Laube, of the German 

 polar expedition, writes as follows: There are certain gla- 

 ciers that occur on the east coast of Greenland which have 

 received the very well- merited name of Puisootok. This 

 Greenland word indicates places where the ice breaks up out 

 of the sea, or where a glacier pushes its ice along under the 

 surface of the sea until its advanced portions, being broken 

 off, rise to the surface as icebergs. These glaciers are all 

 distinguished by very great breadth and a very gentle angle 

 of descent. Icebergs are found in their neighborhood such 

 as never occur in West Greenland, wedge-shaped or rounded, 

 with steep edges. They are, at the upper ends, pointed and 

 dome-shaped, very dense, and rising, according to accurate 

 measurements, to a height of two hundred feet above the 

 surface of the water, with a correspondingly great circum- 

 ference. This kind of iceberg is very distinct from the 

 cracked and jagged ones that are formed from the abruptly 

 ending glaciers, and equally distinguished from those that 

 are formed from flat glaciers, whose strata project over the 

 water. Laube thinks that those grand glaciers which shove 

 in front of them icebergs having heights of six to eisjht hun- 



