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Geology. — ''Facts hadi/H/ to trace out tlie motion and the origin of 

 the underyroiind nyitcr in onr sea-j)rovinces'" . By Prof. Euo. 

 Dubois. (Coiinmmicuted hv Prof. H. W. Bakhuis Roozeboo.m). 



(Communicated in tljc meeting of June 27 tb, 1903). 



As to the origin and the condition of the nndergronnd water in 

 our low-lands, we are, as vet, almost entirely in the dark; facts, 

 that niiu'ht llii-ow lighl on I he subject, are almost entirely lacking. 



The hazardous suppositious made on the subject by some, and 

 the extraordinary caution, which others thought necessary in practice, 

 prove this. Only hilely Dakvpsky, in a dictatorially written article, 

 held forth that e\en now rivers of former geological periods 

 follow theii very same channels, but now as underground streams. 

 The Tuiderground water he considered as almost exclusively river- 

 water '). 



Others have admitted }»owerful artesian currents from the eastern 

 high-land, without any decided facts supporting that opinion. Again 

 others fancied to ha\e found the explanation in Volger's hypothesis, 

 on the condensation of vaj^our in the gromid; a hypothesis, refuted 

 already a long time ago by no less an authority than Hann -). A single 

 phenomenon obser\ed in one of the East-BMsian Islands, already 

 3'ears ago observed in our own country, and explained, but no>v 

 forgotten, led some to imagine possibilities, as to the sea threatening 

 us also from l)elow, a thing which tilled them with anxiety. Not to 

 mention altogether absurd and physically impossible suppositions. 



However ii appeared to me that an earnest searching for facts, 

 could not but bring to light something that w^ould give us a clue, 

 further to lind our way in this important question, important both in a 

 scientiiic and a practical respect. Indeed, thanks to the kindness 

 I met from ditferent sides, I Avas enabled, during these latter mouths, 

 to make a large number of observations and to collect facts which 

 show forth, in outline, the direction, the origin and the general 

 condition of the underground water in the main part of our 

 low-lands. 



Since it will take some time fully to work out the results obtained, 

 the present circumstaiu'cs make it desirable I think, already now, in 

 this short communication, to make known tlie most important of 



1) L. Darapsky, Die Tiiukwasseilïagc in Amsterdam. Journal fur Gasbeleuchtung 

 und Wasserversorgung. iG Jahrgang, p. 468, sqq. (1903). 

 -) J, Hann, Zeitschrifl fur Meteorologie. 1880, p. 482—486, 



