I'm going to add a 'perhaps' here on this one .
Maybe this was a water dispenser , in a kitchen .
Of course , it would have had to sat on something quite substantial , if it was used above floor height ; it'd be most convenient is if was off the floor (in an alcove , etc.) .
If this item was this , perhaps the baffles inside of it would have prevented some 'sloshing around' of the water , when being filled via bucket(s) 'blindly' overhead & would have kept the worker from being doused .
This guess also assumes that there was not indoor running water , at the location where it was used (prob. had to huck it up from a well) .
Another possible here is that the small 'vent' inside of this item was a spot for a dowel-ish thingie (for a water gauge) .... perhaps could also be used as a siphon , in the event of a hand-valve clog , or to remove excess sediment .....
The image posted does seem to indicate that different liquid levels left their marks on it's interior .
It also seems too nice to be sitting out-of-doors .
Looks like this puppy is tough enough to handle hot water too ...
Fecal matter in rivers & streams was a concern for folks in-the-know , when it came to drinking water ... not so much of a concern (way back then) for washing & so forth .
Then again , this may simply be a predecessor of an item like the modern one in the image below .
Talk about your wine-in-a-box !
That's my penny guess , so far .