William Armstrong, twice IMechE president, and Niagra Falls have something important and still relevant in common: hydroelectricity. Water has been harnessed as a source of power for many hundreds of years and the potential for generating electricity from moving water became apparent. As one of the largest waterfalls in the world, Niagara Falls presented tantalisingly huge potential for generating hydropower. In 1899 it was calculated that the daily force of water passing over the Falls was equal in power to that of all the coal mined in the world each day, then around 200,000 tons. The International Niagara Commission (with IMechE past President William Cawthorne Unwin as its secretary) considered how to develop hydroelectricity, whilst maintaining the beauty of the area. The Falls remain a significant hydroelectric site today.
At the same time, on the other side of the Atlantic and on a rather more domestic scale Armstrong was turning his home Cragside into the first house in the world to be powered by hydroelectricity: initially producing enough to power 37 lights (but only 9 at any one time!), or 925 candlepower. His views led to implementation: “[coal] was used wastefully and extravagantly in all its applications”, he predicted in 1863 that England would cease to produce coal. He also supported solar power, stating that the solar energy received by 1-acre in tropical areas would “exert the amazing power of 4000 horses acting for nearly nine hours every day. Today Armstrong has been proved right on coal in the UK but we still debate how best to move away from fossil fuel powered energy/electrics.