Hi Karl,
Welcome to WAGS!!
I can't say that I have ever seen that mark before. Maybe someone else has though.
I also notice that this pot does not have a gatemark on the bottom. This would be a line or scar in the casting where the molten iron entered the mold. Items with this bottom gatemark are generally considered to be older than 1880-1900, but that is just a rough guess really.
If you look closely around the outside of the rim, at the top of the pot, you may see an area or two that appears to have been ground. This is where the side poured gate was normally located. This will help determine the century that your pot was made in. A good first step.
I did find another pot with an anchor, but it looks nothing like yours. Back in May of 2009, one of our members found a pot marked S&H Co, and it had an anchor mark.
http://www.griswoldandwagner.com/cgi-bin/yabb/YaBB.pl?num=1242990473/5#5 This pot does have a gatemark on the bottom, so is probably older than yours.
It might be helpful to post a picture from the side, so we could get a better sense of the style of the item.
Chris