Unknown structure under hearth

[ChorleyJ]

I've removed the hearth and need to plaster the wall where it was. Unfortunatly there's a curved pot / brick object under the fireplace. It goes under the base of the fireplace. I'd like too remove the bit sticking out but concerned that it may be partly supporting the chimney. Does anyone know what it is and whether I can remove the bit sticking out? Thanks.

 

[mattylad]

Its not supporting the chimney, there is about 8" of bricks above it.

 

[ChorleyJ]

Thanks for assurance. Drilled a line of holes along the sticking out bit and managed to remove it with the rest of it unaffected. Wierd thing. The visible bit is like doughnut but goes back some way. Really solid.

 

[jj4091]

Perhaps at some stage it had a Baxi Burnall fire and that was the underfloor ventilation.