Image 2. Willoughby Falls by Charles Kerry Studio uploaded to Flickr by the Powerhouse Museum.
The Powerhouse Museum has posted two images on Flickr from the Tyrrell Collection which are identified in their caption as being Willoughby Falls. Both images are by the Charles Kerry Studio. Willoughby is a suburb of Sydney.
Image 3. View of a waterfall from the Phillips glass plate negative collection held by the Powerhouse Museum
Recently another image of a waterfall was added to Flickr by the Powerhouse Museum, this time from the Phillips collection, but without any identifying caption. Comparing the three images, that is the two known photographs of Willoughby Falls and the third unidentifed falls, I thought it likely that the third photograph too was of the Willoughby Falls. See some discussion of my reasons in the Flickr comments section here.
But how to confirm this?
"Primrose Park was originally occupied by the Cammeraygal people.
The Willoughby Falls area in the western gully was a favourite picnic spot in the early days of white settlement."
That page also leads to "Primrose Park - North Sydney Harbour Foreshore Bushwalk Guide" which contains a map with a clearly marked waterfall.
Checking it on Google Maps I see the geotagging on flickr by the Powerhouse Museum has also linked through to Google Maps which by clicking through links directly to the old-time image of Willoughby Falls in the Tyrrell collection.
A field trip is required.
Primrose Park is built on reclaimed land and the waterfall is in the north-west corner of the park shown here
the remnants of the North Sydney sewage treatment plant can be seen in the middle distance. The sewage works were completed in 1899 to service North Sydney parts of Willougby and Mosman. It closed in the late 1920s.
As far as I can make out from online sources, the Sewage works employed a number of different methods for treatment and or discharge over the years of operation.
This must have involved some works on the course of the Willoughby Falls and its run-off creek because some human intervention has created a U-shaped channel at the bottom, pictured here:
Notably, there is an aqueduct in the middle distance supported by two reinforced concrete columns which are plain with Doric capitals shown closer here:
But, to the falls. In Summer, the flow of water down the falls was only a trickle, but the form and geometry of the rocks could be seen here:
Looks nothing like the Images 1, 2, & 3, eh?
It seemed to me that some of the very large rock forms visible in Image 7 were so large that they were neither the result of construction rock blasting, nor would they have moved there in the past 100 years given the generally stable geology of the area.
Let's approach it from another direction. From the top.
Grafton Street, Cremorne runs above the top of the north-west edge of Primrose Park, and is about 70 metres above the area where I took the photograph Image 7.
Google Street view shows the outlook from Grafton Street to above Willoughby Falls here.
The concrete apron you see between the edge of the road and the fence is directly above Willoughby falls, and gives some idea of the major construction works which have been undertaken in the immediate area over the years.
So,I went to the fence, looked down and could see the top of Willoughby Falls:
Due to the point of view, the photograph does not adequately convey the distances involved. The sandstone ledge you see at the bottom of Image 8 is about 1.5 metres below the camera. The next green coloured sandstone ledge above it in Image 8 is about 3 metres below the camera.
The pool of water in the middle of Image 8 is about 20 metres below the camera.
Due to the near vertical drops on either side of the upper falls I was unable (unwilling) to get a front view of the upper falls for comparison with Images 1, 2, & 3.
Perhaps someone else will be more intrepid.