up-to-date map available. The sheets with the remaining subjects do not change,
substantially cutting down on damages and mistakes in the procedure.
Although relatively more expensive base material is used, the costs connected with
this unique method are importantly less than those connected with the conventional
Photographie method, where the labour involved in drafting each change is consider-
able. This cost saving factor is particularly evident when the use of the divisional-sheets
extends over a number of years.
50 Kilometers
r—t
25 seamiles
Delfzijl
ENGLAND
Amsterdam
NETHERLANDS
Rotterdam
DÜTCH CONTINENTAL SHELF
Block division
RIJKSWATERSTAAT
DIRECTIE BENEDEN RIVIEREN
AFDELING HAVENMONDEN
Fig. 1. Sheet index
shelf.
of the Documentation Sheets 1 50 000 of the Dutch part of the continental
278
K.N.A.G. Geografisch Tijdschrift VI (1972) Nr. J
