After my post yesterday (shouldn't rely on memory alone!), I checked
Bobrick "Labyrinths of Iron:  A History of the World's Subways" 1981.
Bobrick has a chapter on Beach and the pneumatic, including mention of
the hydraulic shield churning through the foundations of an "Old Dutch
Fort"--no word on whether this was, in some way, definitely identifiable
as a Dutch-period fort, or if, in 1870, that was the assumption about an
unidentified foundation encountered below Broadway.  The company that
re-encountered the pneumatic subway and its station was the BMT--not the
IRT, as I stated yesterday--apologies--date of rediscovery was 1912, 42
years after the pneumatic had opened, 38 years after it had closed.
Much of the rest of Bobrick's discussion is as summarized in the second
link in Daniel Davis's post here.  City Hall Station now occupies the
space once held by the pneumatic and its station, though the 1870
station may still exist, "behind a wall."  Unlikely, but stranger things
happen.  The tunnel itself, and the "Dutch" fort/foundation, sound as if
they were taken out entirely in construction of the station.  Bobrick
states that iron/steel machinery from the c. 1870 hydraulic shield were
salvaged, and taken to Cornell University, where they became part of the
collection in the Department of Engineering.  Any word on that?

D. Babson.


-----Original Message-----
From: HISTORICAL ARCHAEOLOGY [mailto:[log in to unmask]] On Behalf Of
Davis, Daniel (KYTC)
Sent: Monday, May 15, 2006 8:26 AM
To: [log in to unmask]
Subject: Re: sub-rosa subway

...and here. Cool photos and maps, as well.
http://www.columbia.edu/~brennan/beach/

-----Original Message-----
From: HISTORICAL ARCHAEOLOGY [mailto:[log in to unmask]]On Behalf Of
George Myers
Sent: Sunday, May 14, 2006 3:46 PM
To: [log in to unmask]
Subject: Re: sub-rosa subway


http://members.tripod.com/earthdude1/subway/subway.html

Very good description of its history here: