sewer

Is that the Croton Aqueduct in the background?

it's the viaduct (Riverside Drive) that extends from Riverside Park where Claremont Inn stood to 135th street. There used to be a ferry just beyond the viaduct

Yeah, I saw a show on TV the other day about NYC's water supply (including the aqueduct), and forgot to go remove my dumb question. Thanks for setting it straight!

The photo was taken in Manhattanville (West Harlem). The photo shows the aftermath of a burst water main on West 129th Street just east of the crossing at Broadway which occurred on June 23rd, so the photo was probably taken later that month. The NY Times reported ("Flood Rages In Manhattan Valley," June 24, 1911) the loss of 3,000,000 gallons of water from the "city's dwindling supply" and $10- to $15,000 in property damage. The vertical girder to the left holds up the elevated section of the Manhattan Street subway station -- renamed 125th Street Station in 1921 -- of today's #1 line. The front of the white Sheffield Farms building in the central background (built in 1908, and known today as Columbia University's Prentis Hall) is obscured by a frame structure on the triangular block where area locals will recall the Floridita Cuban Restaurant was located until recently and where a gas station is still in operation. To learn more about this fascinating old NYC neighborhood, see my book, "Manhattanville: Old Heart of West Harlem." Thank you LOC for sharing this pic, which I'd never seen, although I immediately recognized the event.

Thank you, Eric, for your synopsis of the event and details about the neighborhood. We'll fill in the caption information and date the next time we update the record. I hope that you will continue to browse our images and share your research. Your book sounds fascinating.

That looks like a tripod mounted theodolite on the balcony.

Yes, it does. I'll see if I can find a larger version of this image so we can get a bit more detail....DONE!

A larger version will also help to show the built up area on the background hill. I originally thought this was Kosciusko, but no way is that the case with those buildings in the background. Buildings also make it likely there is a local historical society somewhere that has a good idea where this is. @Wragge on twitter (Dr. Tim Sherratt) also knows a good deal about the history of meteorology in Australia. We may need to tap him for this one.

Thanks and for those following these comments @wragge on Twitter was a great help and believes this to be a surveying station rather than a weather station. We will contact the Observatory as advised and see what else we find out.

I think that is Sydney town in the right distance - no NSW country town would have so many spires and large houses. We are looking west-ish (see shadows) from some surveying spot near Bondi. Maybe something to do with the Bondi sewage outfall? The large size image certainly helps. I am amused that with all that surveying equipment etc, they could not get the camera level!