Riddle me this: what has 24 wheels, weighs more than three Jumbo Jets, and can pull five miles (eight kilometers) of cargo at seventy miles per hour full steam? That last clue should easily give it ...

Horsepower is a relic of the steam age, yet it still dominates spec sheets, showroom chatter, and online debates about engines. Even as engineers rely on watts and kilowatts, the car market, ...

When an inventor has a unit of measurement named after him, it's clear his work had more than a small impact on scientific and industrial progress. So it was for James Watt, whose Watt engine is often ...