This installation was created by Wolfgang Weileder.  A plaque by the side of the lake provided the following information:

On Nelly’s Moss Lake the artist has installed three dinghies to remind us of the power of wind and water and offers us a new visual experience and interpretation of Lord Armstrong’s inventive and visionary spirit.

The images on the sails are direct replicas of photographs to be found in Armstrong’s book, Electric Movement in Air and Water (1897) – the title of this work.

These electrical discharges were a product of Armstrong’s continued passion for discovery as he embarked upon electrical experimentation later in life.

When we visited one of the dinghies had capsized and was at the side of the lake.  It must has succumbed to some excessive air and water movement.

For those who are curious about the fourth installation that I did not manage to photograph, it was entitled Give and Take and was the creation of Jo Coupe.  It was situated in the Electrical Room which has not been open to the public for a number of years pending renovation.  The Cragside House Blog shows photos of the exhibit being installed and provides the following information:

This piece consists of 5 tanks filled with copper sulphate solution which will, over the course of the rest of the season, copper plate long-stemmed roses – a live electrical experiment! This one really represents the space it fills. The Electrical Room was the area purpose-built for Lord Armstrong to conduct his own Electrical experiments, although none quite like this.