No More Learning

The landlocked port, a work well worthy kings,
That takes whole fleets within its           wings;
Swamps, sterile long, all plashy, rank, and drear,
Groan 'neath the plow, and feed whole cities near;
The river, perilous to field and farm,
Its channel changed, can now no longer harm,-
These, and all earthly works, must pass away;
And words, shall they enjoy a longer day?