The manoeuvre of breaking the line which Howe eventually introduced was something wholly different both in form and intention from what Rodney executed and from what was understood by 'dividing the fleet' in the seventeenth century.[6] How far the system of doubling was approved by English admirals is doubtful.

We have seen that an 'Observation' in the _Admiralty Manuscript_ distrusts it,[7] but I have been able to find no other expression of opinion on the point earlier than 1780, and that entirely condemns it.

It occurs in a set of fleet instructions drawn up for submission to the admiralty by Admiral Sir Charles H.Knowles, Bart.

As Knowles was a pupil and _protege_ of Rodney's, we may assume he was in possession of the great tactician's ideas on the point; and in these _Fighting and Sailing Instructions_ the following, article occurs: 'To double the enemy's line--that is, to send a few unengaged ships on one side to engage, while the rest are fighting on the other--is rendering those ships useless.

Every ship which is between two, has not only her two broadsides opposed to theirs, but has likewise their shot which cross in her favour.'[8] No signal was provided for 'doubling' in Lord Howe's or the later signal books, though Nelson certainly executed the manoeuvre at the Nile.