embankment was very high in proportion to the area secured; and hurricanes
from oceanward sometimes raised the streams until they over-topped the
banks and broke them. If these invading waters were briny the standing crop
would be killed and the soil perhaps made useless for several years until
fresh water had leached out the salt. At many places, in fact, the water
for the routine flowing of the crop had to be inspected and the time
awaited when the stream was not brackish.

[Footnote 4: David Ramsay, _History of South Carolina_ (Charleston, 1809),
II, 201-206.]

Economy of operation required cultivation in fairly large units. Governor
Glen wrote about 1760, "They reckon thirty slaves a proper number for a
rice plantation, and to be tended by one overseer."[5] Upon the resort to
tide-flowing the scale began to increase. For example, Sir James Wright,
governor of Georgia, had in 1771 eleven plantations on the Savannah,
Ogeechee and Canoochee Rivers, employing from 33 to 72 slaves each,
the great majority of whom were working hands.[6] At the middle of the
nineteenth century the single plantation of Governor Aiken on Jehossee
Island, South Carolina, of which more will be said in another chapter, had
some seven hundred slaves of all ages.

[Footnote 5: Carroll, _Historical Collections of South Carolina_, II, 202.]

[Footnote 6: American Historical Association _Report_ for 1903, p. 445.]

In spite of many variations in the details of cultivation, the tide-flow
system led to a fairly general standard of routine. After perhaps a
preliminary breaking of the soil in the preceding fall, operations began in
the early spring with smoothing the fields and trenching them with narrow