( 473 ) 
during the years 1862 — 1906, that the soil of the Netherlands is 
still sinking, and that this sinking amounts to about 18 cm. a 
century. 
On the other hand Van de Sande BakhuYzen *) has derived from 
observations concerning the level of the official A.P. at Amsterdam, 
that it remained constant from 1700—1860, and that accordingly 
the ground of Amsterdam neither rose nor sunk during that period. 
The results to which Ramaer and Van de Sande Bakhuyzen have 
come, are not very well to be brought to accordance, unless we 
assume that the sinking set in again after the year 1860 after a 
period of rest, or as Mr. Ramaer is inclined to believe, that at 
Amsterdam also previous to the year 1860 the same sinking took 
place, but that it was just counterbalanced by a movement of the 
ground in consequence of the upward pressure of the underground 
marsh-gas. Neither of these explanations appears to be exempt from 
arbitrariness; for the present, acknowledging the question as an un¬ 
settled one, I will choose the case which is the roost favourable for 
the Netherlands, viz. that of stability of the ground during the two 
centuries preceding the year 1860. 
Summarizing' the geological history teaches, that at least from the 
late-tertiary time the ground of the Netherlands has sunk, that this 
sinking, however, has not been continually perfectly gradual, but 
that it has now and then been interrupted by shorter of longer 
periods of rest or movement in an opposite direction. Lorie has 
demonstrated one period of opposed movement with certainty in the 
lagoon stage while we may conclude to others with great probability 
on similar grounds. Also it has been concluded from the stability of 
the level of the A.P. at Amsterdam that there has probably been a 
period of rest during the two centuries preceding the year 1860. 
Before discussing the practical signification of this result it is 
necessary to inquire into the real nature of this subsidence. 
The movement of a block of land with regard to the surface of 
the sea may be caused either by actual movements of the land or 
by variations of the height of the sea-level. To evade the difficulty 
of giving a decision in every case, a neutral nomenclature has been 
adopted, and we speak of a positive and a negative shifting of the 
coast-line. 
In our case, however, the decision is not difficult. 
The sinking of the soil of the Netherlands has been an exclusively 
local phenomenon as appears from the above tables I and II. At short 
^ H. G. VAN DE Sande Bakhuyzen. “The height of the mean sea-level in the Y 
before Amsterdam from 1700—1860”. These Proc. X p. 703. 
