176 Early Agriculture
the fertility-bearing rivers as closely as possible, and in doing so they had to find
ways of draining the lowland marshes and strengthening and reshaping the river
banks. Naturally the question of inland navigation did not arise everywhere. Exist-
ing rivers and streams might be suitable for irrigation, but not for shipping (Pueb-
los, Chagga, Highland Peru); or the ocean might prove an ideal means of
transportation (Hawaii, Coastal Peru). In certain localities inland navigation was
satisfactorily served by man-managed rivers (Egypt, India) and lakes (Mexico) plus
whatever irrigation canals were large enough to accommodate boats (Mesopota-
mia).
But when supplementary watercourses were not only possible but desirable,
the organizers of agrohydraulic works had little difficulty in utilizing their coop-
erative ‘apparatus’ to make them available. The new canals might be only minor
additions to the existing watercourses. The ancient Egyptians constructed canals in
order to circumnavigate impassable cataracts, and they temporarily connected the
Nile and the Red Sea;^44 but these enterprises had little effect on the overall pattern
of the country’s hydraulic economy. In other instances, navigation canals assumed
great importance. They satisfied the needs of the masters of the hydraulic state: the
transfer of parts of the agrarian surplus to the administrative centres and the trans-
port of messengers and troops.
In Thailand (Siam) the different hydraulic tasks overlapped. In addition to the
various types of productive and protective hydraulic installations, the government
constructed in the centres of rice production and state power a number of canals,
which essentially served as ‘waterways’, that is, as a means for transporting the rice
surplus to the capital.^45
The corresponding development in China is particularly well documented. In
the large plains of North China the beginnings of navigation canals go back to the
days of the territorial states – that is, to the period prior to 221 BC, when the vari-
ous regional governments were still administered by officials who were given office
lands in payment for their services. The difference between the state-centred sys-
tem of land grants as it prevailed in early China and the knighthood feudalism of
Medieval Europe is spectacularly demonstrated by the almost complete absence of
public works in feudal Europe and the enormous development of such works –
hydraulic and otherwise – in the territorial states of China.^46
The geographical and administrative unification of China which vastly increased
the political need for navigation canals also increased the state’s organizational power
to build them. The first centuries of the empire saw a great advance not only in the
construction of irrigation canals,^47 reservoirs, and protective river dikes but also in
the digging of long canals for administrative and fiscal purposes.^48
When, after several centuries of political fragmentation, the Sui rulers at the
end of the 6th century again unified ‘all-under-heaven’, they bulwarked the new
political structure by creating out of earlier and substantial beginnings the gigantic
Imperial Canal, significantly known in China as Yün Ho, ‘the Transport Canal’.
This canal extends today for about 800 miles, its length equalling the distance
from the American-Canadian Great Lakes to the Gulf of Mexico or – in European