This was one of the first covers of the new Hydro Review magazine, when the illustrations were still printed in black and white. That would have been in the 1980s. The theme of bells and whistles referred to all of the gadgets and gizmos associated with hydroelectric machinery. So I included a bell and an old-fashioned steam whistle, along with an array of belts and pulleys. I still like the assembly line delivery of lightning bolts rolling along the conveyor belt.