E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
The national banner of Great Britain and Ireland. It consists of three united crossesthat of St. George for England, the saltire of St. Andrew for Scotland, and the cross of St. Patrick for Ireland.
In the Union Jack the white edging of St. Georges cross shows the white field. In the saltire the cross is reversed on each side, showing that the other half of the cross is covered over. The broad white band is the St. Andrews cross; the narrow white edge is the white field of St. Patricks cross.
In regard to the word Jack, some say it is Jacque (James), the name of the king who united the flags, but this is not correct. Jacque is a surcoat emblazoned with St. Georges cross. James I. added St. Andrews cross, and St. Patricks cross was added in 1801. (Jaque, our jacket.)
Technically described thus:
The Union Flag shall be azure, the Crosses saltire of St. Andrew and St. Patrick quarterly per saltire counterchanged, argent and gules, the
latter fimbriated of the second, surmounted by the Cross of St. George of the third, fimbriated as the saltire.By order of the Council.
Jaque, de lallemand jacke, espèce de petite casaque militaire qu on portait au moyen âge sur les armes et sur la cuirasse.Bouillet: Dictionnaire Universel.