Chart Fig 177 is for sand, not clay. Stiff, etc. applies to cohesive soil. On the subject, in the last few years somehow "medium or firm" are "old fashioned". Now it is "medium dense" in my area. Why not "medium loose" or "very medium"? Also, how's come "soil engineering" is now "geotechnical engineering", a longer fancy sounding word to mean the same. Maybe makes for longer report length to impress someone I suppose.