>> I'm afraid it seems that that was how they heated the water in
>> 'cooking pits'. Cf Fergus Kelly, 'Early Irish Farming' 336. You
>> can't light a fire under a pit, but you can light one under a
> But let's just suppose that the 'superheated rock' you put in a cooking
> pit could be called a 'bruth' (just like a mass of heated metal can be).
Rocks heated in the open fire were also used to heat bath water.
These weren't called "brotha" (pl. of "bruth") however, but rather
prosaicly "clocha fothraicthe" (DIL C 248.32-6).