On my volcano grows the Grass — Fireplace

On my volcano grows the Grass 1
A meditative spot-
An acre for a Bird to choose
Would be the General thought-

How red the Fire rocks below-5
How insecure the sod
Did I disclose
Would populate with awe my solitude.
(F.1743/J.1677)
[1] volcano:: alluding the fireplace at home. Grass:: being free from fixed engagements (OED 5); leisure time without work.
[2] meditative spot:: a place where she could dream.
[3] Bird:: a small secret.
[4] general thought:: no so serious thinkings.
[5] red the Fire:: the glowing passion. below:: lower part of the body; sexually.
[6] sod:: a fellow, chap.
[7, 8] disclose, solitude:: if she disclosed her secret, she would be more alone.