Midstonehall or Neilsland House, as it later became known, was extended around 1891-1893, I would imagine that the fountain went in around then...no idea about powering pumps though.
We do know that pipes were laid over the estate coming from Torlake, behind Torheads Farm.
I did try to post a photo of the house and fountain but unfortunately the file was too large...any suggestions on how to overcome this?