14 down Fish - am catching fifty in due time (3-6) S?A ?A????
15 down Semi-Christian sect apt to leave anabaptists confused(8) ?S???A??
16 down Book of songs accompanied by unknown instrument(8)?S???E?
Many thanks but I think 16 down must be psaltery. Your psalter gave me the clue and I looked it up and psaltery is a musical instrument. I missed a ? off the end it was 8 letters.