Plate 17 FARM WALKS OF "NEVALLAN"      Upper: Party of Queensland farmers arrive by two specially chartered 'buses making a 1500-mile trip specially to see Keyline development on "Nevallan". There have been a number of such visits.    Lower left (from left to right) : The author, Lady Hicks, the author's wife, and Sir C. Stanton Hicks, at "Nevallan".    Lower right: Graduates in Agriculture from the Sydney University visit "Nevallan" following the author's address at their Graduation Ceremony mentioned in Chapter XIII.