For in the first place it is to be remarked that the sinking of obstructions in an enemy's harbours in order to render more effective a blockade was no novelty in maritime warfare, as Russell must have well known, and that there was no modern record of such obstructions having permanently destroyed a harbour.

A far more reasonable explanation is that which connects the energy of the British Government in opposing a proposed American closing of Southern harbours by Presidential proclamation, with a like energy against the stone boat project.

The first method was indeed rightly regarded as a violation of accustomed maritime belligerency, but both methods were primarily objectionable in British eyes because they were very evidently the result of efforts to find a way in which an as yet ineffective blockade could be made more rigorous.

On the impossibility of an effective blockade, if conducted on customary lines, the British people and Foreign Secretary had pinned their faith that there would be no serious interruption of trade.

This was still the view in January, 1862, though doubts were arising, and the "stone boat" protest must be regarded as another evidence of watchful guardianship of commerce with the South.