11A - Ballarat's was apparently a brilliant discovery (8) - I have ???C?A?E
26A - relations in some garbled taverns airs (10) I have ??R?A???E? - an anagram I assume but I don't get it
17D - historian promoting cultivation, we're told (8) I have ?A?D????
16D - he has naturally selected his belief (9) I have D?R?I???T