columns (and column) undefined

datatables.net 1.10.3

the following code results in an error "Object doesn't support property or method 'column'". i get essentially the same error if i try columns() instead.

for (i = 0; i < 6; i++)
tbl.column(i).visible(false);

but the following works:
for(i = 0; i < 6; i++)
tbl.fnSetColumnVis(i, false);