Leaning back in his arm-chair of an evening, he would close his eyes and scrape carelessly at the fiddle which was thrown across his knee.
I think the scrape means play here, fiddle means violin. But the part 'which was thrown across his knee' confused me. 'which' is referred to the 'fiddle', right? so does that mean he threw the fiddle on his knee? thanks. If he was playing violin, how he put it on his knee; if he was not playing, then did the author merely mean he just scrape the violin?