I found the guns pictured in the below website.
Which is tricky to get to - I can't seem to save the web site properly.
A Google search of 'CAMP No. 168 Cohoes, NY' will get you there.
I pulled down a picture of them from the site.
They are visible on Google - Street View: 90 Oneida St Cohoes, NY
They are trophy guns from the Spanish-American War.
They look like fortress or 'coast defense' type guns.
I couldn't get a sniff of them from the near magnificent http://www.spanamwar.com/spanishf.htm site.
Thanks in advance.
Charles