PORT ECONOMICS
most distant port from which the vessel has arrived or to
which it is bound. Pending adjustment of the amount due,
the Port Rates Collector generally receives a deposit on
account, sufficient, in his opinion, to cover the charge,
and thereupon he furnishes a certificate to the Collector
of Customs enabling the Entry of the vessel to be made.
Clearance Outwards is not permitted until a receipt for
the full amount of the rates has been produced for the
inspection of the Customs officer. A vessel may be legally
detained by a port authority until all rates have been
paid. As regards rates on goods as apart from tonnage
rates, it is the general practice for merchants and others,
with a great number of transactions during the course of a
year, to keep a Deposit Account with the port authority ;
the balance in hand suffices to cover the amount due
between periodical adjustments. The procedure is similar
in principle to that of keeping an account at the bank to
meet the presentation of cheques for payment.
2. The Canvassing Department endeavour to secure for
the port as much traffic as possible, by soliciting business
among merchants, and others, pointing out the advantages
of the port and so attracting goods for export, as also by
offering inducements in the way of better facilities for
vessels arriving with imports. The field of their activities
is the hinterland, which has been mentioned in Chapter I.
The considerations which will induce merchants and shipowners
 to select a port for shipment and discharge are
various, and, in some cases, involved. Goods do not
always go to the port nearest, geographically, to their
ultimate destination for reasons which may not be apparent
on the surface. Financial, commercial and insurance
interests may cause a considerable deflection of route.
London is the leading British market for wool, though the
material ultimately goes to Yorkshire. Much rice is consigned
 to Hong-Kong, for dispatch elsewhere. Indeed,
many commodities find convenient centres for sale and distribution
 at ports not on their direct route. Rubber and

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