hist-brewing: old time sparge techniques

[Greg Peters]

Dave,
    
>From what I have read. brewers used to    do succesive mashes also known
as parti-gyle brewing.  Mashing in with a heavy amount of grist and
afterward simply draining the mash tun completely.
Then a second charge of hot liquor (sparge water) was added to the mash
tun for a second mash.  Again,  the  hot wort   was drained completely.
sometimes. a third batch was done which resulted in  a   much weaker
brew known as small beer.

Bear in mind that each time, the mash was allowed to rest so that more
of the starches in the grains could be converted to sugars.   This
resulted in beers of   different strengths.
I hope this helps to answer your question.
Greg