In Spragge's first 'Sea Book' there is another copy of them identical except for a few verbal differences with those in the second 'Sea Book.' In the first 'Sea Book' they appear on the back of a leaf containing some 'Sailing Instructions by the Duke of York,' which are dated November 16, 1666, and this is the latest date in the book.

Moreover in this copy they are headed 'Additional Instructions to be observed in the next engagement,' as though they were the outcome of a previous action.

Now, as Wren died on June 10 (o.s.), and the battle of Solebay, the first action of the Third War, was fought on May 28 (o.s.), it is pretty clear that it must have been the Second War and not the Third that was in Spragge's mind at the time.

Still if we have to put them as early as November 1666 it leaves the question much where it was.

Besides the idea of containing the main body of the enemy after cutting off part of his fleet, the death penalty for firing over the line is obviously designed to meet certain regrettable incidents known to have occurred in the Four Days' Battle.