Lovat's ghost on pilgrimage / The original of this very scarce print, of which this is a facsimile, was added to the collection of Mr. Ireland by Doctr. J. Webster, an intimate friend of Hogarth from whose hands he receiv'd it soon after the execution of Lord Lovat with an assurance of it's being his own design.

A facsimile by Ireland of an earlier print, the publication line for which is reproduced under the design: "Publish'd according to Act of Parliament, June 15th 1747". According to Ireland the original design was by Hogarth, but this attribution is not certain.
Not in British Museum?
See under Paulson. Hogarth's Graphic Works (1965), no. 288.