Merrill Wisconsin - an odd gun in the Park

 Seen in a Veteran's Memorial park, Merrill Wisconsin.

It is of course an artillery piece, but what an odd one.  Huge springs!  Let's look for additional clues.  Here's a view that shows more, although with light that is less good.

And some helpful markings around the business end of things:

These read: 7 inch No. 48 Wt. 1689 lbs.  JPF Insp. Watervliet Arsenal 1900.  Elsewhere on the gun it says Model 1892 Bethlehem Steel.  Although that might be the gun carriage, not the gun proper.  Finally, there is a bronze bit that has stamped on it: No. 48 Model of 1895 Watertown Arsenal.  I'm a bit confused now.  So what is this critter?

To start things off, Watertown Arsenal and Watervliet Arsenal are not the same outfit.  The former mostly made gun carriages.  The latter made the guns, and as in this case, the howitzers.  Howitzers are short, stubby, larger caliber weapons designed to fire shorter distances and at very high angles.

So far so good.  But this is a very odd bit of artillery.  Most of what you see in assorted war memorials are either WWII surplus stuff or captured items from I or II.  This is neither.

It appears to be an item of obsolete coastal artillery.  That's a much less common variety of monument, but you can see how they'd get surplused.  I've run into one or two in my travels.  But nothing like this critter.

Even without the dated plaques it has to be 1890's tech.  Earlier artillery pieces would usually have wheels and/or some means to solidly dig into the ground or be welded to the deck of a ship.  Every time you fired it the recoil would move the gun and you'd have to reposition it.  In 1897 that all changed, when the French unveiled their 75mm cannon with hydraulic recoil dampening.  This was the model for all artillery for the next hundred years.

Before that there must have been assorted experiments with springs and similar gadgetry.  I've nosed about here and there in sources and can find nothing specific on this "thing", perhaps the internet will toss me an answer.

Was this some low production run experiment?  Some boondoggle project right around the Spanish American War when somebody in the War Office bought the fantasy that the Spanish fleet might sail into Boston harbor some day?  Who knows.