The text is an excerpt from Henry Holiday’s The Snark’s Significance (1989).
Page from a letter (1876-01-04) by C.L. Dodgson (aka Lewis Carroll) to Henry Holiday. The two lines at the bottom are notes written by Henry Holiday.
I think the note is:
× L.C. forgot that “the Snark” is a tragedy and [should]
on no account be made jovial. h.h.
In the end, Carroll produced a tragicomedy.