16Much of the latter part of this paragraph is in fact derived from Lovecraft's own short stories, most notably "The Picture in the House", which featured the sadistic Robert Pickman character. Also, Lovecraft repeatedly cites Chambers' book as his main inspiration, although he created the Necronomicon before he first read Chambers. KKC
The story featuring Robert Upton Pickman is, of course, "Pickman's Model", not "The Picture in the House". See above on Chambers. I am unaware of any serious statement by Lovecraft attesting to any significant influence from Chambers' work. DC