Fort Hancock's Battery Potter, constructed from 1890-1894, was the first disappearing gun battery in the U. S. Originally called Lift-gun Battery #1, it was the first and only disappearing gun battery powered by a steam hydraulic lift system. There is a YouTube video that shows how this worked here: http://youtu.be/PYxqTGxXybA In operation from 1893-1906, it was obsolete by the time it was built because the fastest firing of the gun took over two minutes. Fort Hancock in Sandy Hook, New Jersey.

Technical details:
Sakai Toyo 5x7 large format metal field camera with 4x5 film back.
150mm Caltar-S II F 5.6 lens in Copal BT shutter.
Arista EDU Ultra 200 (re-branded Fomapan) B&W Negative Film, shot at ISO 160.
1/8th second at F32.
Semi-stand development in Rodinal/Adox Adonal 1:100 dilution for 15 minutes in Mod54 daylight tank.
Negative scanned with Epson V600. Cropped to desired size in post.