In his book "Canberra; Its history and its legends" he writes a short passage describing a living room sized cave...
This cave's location is today not publicly known, if at all. Rumour indicates it was sealed up in the early years of Canberra's development and one can only wonder how the entrance may have been blocked.
What is today known is the Black Mountain Peninsular was a well known riverside corroboree ground. An archaeological survey of this cave would be interesting. The corroborees were happening for a long time before we got here.
Posted about this at the beginning of last year so for new readers... A friend of mine, Dave Wheeler, researches the story. I will pass on any information, story, even rumour through to him that any one may relate.