The Nuttall Encyclopedia
Originally the flag of Great Britain, on which the crosses of St. George and St. Andrew are blended, with which certain white streaks were blended or fimbriated after the Union with Ireland.
Wood, James, ed. Entry for 'Union Jack'. The Nuttall Encyclopedia. https://www.studylight.org/encyclopedias/eng/nut/u/union-jack.html. Frederick Warne & Co Ltd. London. 1900.