( 479 ) 
burg would certainly have destroyed these remains, as they did 
afterwards. 
So this displacement of the dunes inland must have taken place 
between 800—1000 before Christ and 1647. During the first centuries 
after Christ the coast immediately behind the dunes was still inhabited. 
But because the dunes were blown inland, this coast was deserted 
for so far as it became beach, and the inhabitants moved to those parts 
of the island which had been raised and made habitable by deposition 
of silt. Yet the coast, which had partly become beach, continued to 
be used, for some years after 1647 the remains df a canal were 
discovered, which was used by the boats of the herring fishery, and 
is reproduced by Mr. Frederiks on his map of 1866 . l ) It is known 
that Domburg had still a harbour in 1544, from which the boats 
sailed out for herring fishing. 
So there is no reason to assume that first a sinking should have 
taken place between the beginning of our era and the tenth century, 
and still less that a rise should have taken place between the 10 th 
century and the seventeenth century, which caused the remains of 
the temple, the burial ground, and the dwellings from the Roman 
time to reappear. A rise has not been necessary to bring this about. 
J. C. Ramaer, head-engineer of the hydrographic survey, has 
derived 1 st a sinking of 1,3 mm. a year from the water levels observed 
on 8 accurate gauges during 35 years, 2 nd a sinking of 1.6 mm. from 
the observations of a series of gauges in our country during 47 years, 
3 rd a sinking of 1.4 mm. a year from observations during 6 years. 
H. G. van de Sande Bakhuyzen has subjected these records of 
Ramaer’s gauges to a strict critical examination, and has arrived at 
the conclusion, that no reliable results are to be derived from them. 
It seems to me that the Mounds in Friesland and Groningen, and 
also those in East-Friesland, Oldenburg and Holstein might teach us 
something about the sinking, if we examine the bottom or the floor 
(of the mound or hillock) (Wierde, Word or Wurth) with respect 
to the mean high water mark of A. P. For it may be assumed 
that the erection of the Mound or Wierde has taken place on a 
“kwelder” •) (Schor, Groden) which was dry at low water, and gave 
protection from the high water by the raised Mounds, as Pliniis 
l ) Miss Marie de Man: Que sait-on de la plage de Dorabourg? 1899G.Th.Bom 
en Zoon. P. 51. 
a ) A “kwelder” is a new 
side the coast. 
alluvial deposit of clay-silt outside the last dike, < 
