I believe Carolan's planxties originally carried words, usually praise for the patron, most of which are perhaps fortunately now lost.

This text looks to be 18th century: "Johnfon", "liv'd" etc. There was a revival of interest in harping and Carolan's works at the tail end of the 18th century, particularly Edward Bunting's harp festival in 1792. I wonder if this text could date from then?