A whatzit cannon

[cannonmn]

This cannon is cast iron, weighs 84 lbs., is 16.5 in. long, and has a bore of 2 1/4 in.  It was made with no trunnions, on puropse.  I have an identical pair of these.  From the lines of it, including the raised vent field, it looks like a ca. 1800 style cannon.

I've never seen of a fog cannon, made just to make noise as a fog signal, but I know that surplus military cannons were kept at light houses to fire fog signals when required.  Some lighthouses still have them as displays.

I wonder if these two cannons could have been fog cannons, specifically cast to have one and only function, to make noise as fog signals?  If not, what else could they be?  Note that only one of the cannons is shown in all the photos.

[mortarmaker]

Those are interesting Cannons, If they are Flash or Fog cannons,  I would like to see the carriage that held them. Let us know if you find a link.
you sure can dig up the cannons!

[cannonmn]

would like to see the carriage that held them.

I'm thinking that might have been one of the attractions of this design, these could have been held in very simple wooden rack, many side-by-side.  All you'd need really is a thick plank with a big notch cut in it, since these only shoot blanks and recoil would be light.

[cannonmn]

At the bottom of this page is a pic of a large fog cannon, and a little history on it. 

http://www.lighthousefriends.com/light.asp?ID=76

[mortarmaker]

Did I read that right? an 80 ft. cannon! Not to get off course, but what is the purpose of the raised vent field?

[cannonmn]

>raised vent field?

The little bowl it formed contained the priming powder better, making it easier to ignite with portfire or linstock.  It was also probably a good idea to have that at lighthouses, which were always exposed to wind that might blow priming powder off a flat vent pan.  Just a guess.

[Terry C.]

Eight not eighty.

Raised vent fields were mostly found on guns fired with loose priming powder. The raised field helped keep the priming powder from blowing away. Sometimes instead of the raised field, there would be a trough.

Later guns that fired with friction primers didn't need this.

[mortarmaker]

makes sense to me.

[lance]

 i liked reading about the job of having to fire the big gun every half hour, to bad the cost of powder went up and they had to let him go.

[mortarmaker]

 I have a Y seeing disorder;) 80 didn't make much sense at all.