SOLUTION to General Knowledge No. 2606:

Across - 1, Walt Whitman 8, Shofar 9, Itaipu 10, El Al 11, Cotehele 13, Otter 15, Vetch 18, Inkerman 19, Sita 20, Schist 21, Oracle 22, Paul Gauguin. Down - 2, Athelstan 3, Tefal 4, Horace 5, Thirty 6, Arachne 7, Dune 12, Locatelli 14, Evelina 16, Amstel 17, Angola 18, Ilsa 19, Smaug.