I don't know if it's somthing that you would have seen in an English county home in that period, even for a family as rich as the Darcy's, but spouting fountains have been around at least as long at the Roman Empire. They don't necesarily require an external power source. Clever engineering can give you a spouting fountain powered simply by gravity. All you need is a water source higher than the level of your garden, say a stream or pond uphill from your property. If you are lucky enough to have your land situated over an artesian well you could also incorporate that into a garden water feature.