The duchess, who said she had watched her mother die in agony from osteoporosis - a disease that causes bones to become brittle and easily fractured - attended a reception at Government House intended to raise awareness of the disease. It was, she said, the first thing she was determined to do when she knew she was coming to Australia.

The prince, for decades a proponent of sustainable design for housing, took himself off to the Housing Melbourne Symposium at the National Gallery of Victoria to applaud Melbourne's architecture, the preservation of its tram system and the creation of new urban areas for community enjoyment.

''Unlike most cities around the world, Melbourne kept its tram system and improved it and is now considered a global leader,'' he said.

Back at Government House, the duchess told members of Osteoporosis Australia that she believed it was important to spread the message worldwide that the disease could be prevented. She had not only watched her own mother succumb to osteoporosis - her grandmother had also died from the painful condition.

The prince won an attentive audience when he declared that urbanisation was the most pressing challenge of the 21st century, when more than half the global population lived in cities.

His own attempt to confront the challenge, by establishing his Foundation for Building Community, had been a ''lonely road'' from its inception a quarter of a century ago, he said.

As lonely, perhaps, as his journey to the gallery yesterday. The largest part of the tiny crowd of well-wishers outside was a group of old soldiers from the British Airborne Forces Association, Victoria. A small knot of the proud men in scarlet berets stood at attention and gave the royal salute.

Soon after, the prince and the duchess met up to visit the Victorian College of the Arts Secondary School in Southbank.

They were welcomed by students from the Huntingdale Primary School pounding Japanese ceremonial drums, as if, perhaps, they were really emperor and empress. Huntingdale teaches one-third of its curriculum in Japanese, putting it ahead of the current political drive towards an ''Asian century'', and the drums beat the message loud.

''Extraordinary,'' said the prince as he and the duchess swept by to attend performances within the college of the arts secondary campus.

Hardly more than two dozen members of the public stood in the street, but when the duchess - who owns Boston terriers - spied a French bulldog, she stooped to pat it. The dog's name, according to owner Neville Condron, a Coburg resident enthused by all things royal, was Bert.

''Bertie,'' cooed the duchess, possibly recalling Prince Charles's grandfather, and the re-named Bertie reciprocated by licking her hand.

''Yes, Camilla was quite taken with Bert and Bert was quite taken with her,'' said Mr Condron. Indeed, ''Bertie'' had met Prince Charles during a function in South Melbourne only the day before, and the prince, giving the mutt a pat, had opined that ''one of these days, I'll get my hand taken off''.

''Bert's more likely to lick your hand off,'' Mr Condron said.

The royal couple, who flew to Adelaide Wednesday, will travel to Tasmania on Thursday for events in the village of Richmond and the capital, Hobart.

with pool reporters