In the second theme of the recapitulation of Beethoven's Pathetique Sonata where the bass line goes into the treble clef and the bass register becomes part of the melody, I see the marking ben tenuto il basso. I tried looking it up last night and couldn't find an answer. Google translate said that this means "well held down", but that wouldn't be the musical definition, I know it wouldn't.
From finding out that ben in Italian means well and my knowledge of Italian musical terms, here is the best that I could translate it to:
Well held in the bass
So from that translation, here is what I think Beethoven is trying to get across with that marking:
Hold the bass notes as though there was a fermata in the bass, in other words, longer than your normal tenuto, while the melody is an accented staccato.
Is that what Beethoven is trying to get across with the marking?
EDIT: Here is what I see in the Schirmer edition, or whenever I look at Sonata Album Book II published by the same people. I use the Schirmer edition, partly because it makes it so easy to see where the recapitulation starts. But here is what I see in that edition:
As you can see, ben tenuto il basso is clearly marked here under the same measure that has the poco crescendo marking.