What else did these designers and engineers build?

Gustav Eiffel, in addition to building a small tower somewhere, built various bridges for the French railways, notable the Garabit viaduct in the Massif Central region of France. He later became involved in the financial scandal of the Panama Canal.

George Ferris - George Washington Gale Ferris Jr - built a little wheel

for the World's Columbian Exposition in Chicago in 1893. He also designed and inspected railroad bridges, trestles, and tunnels, none of which were famous or spawned hundreds of imitations.

In addition to building steamships, railways, dockyards, bridges

and tunnels, Isambard Kingdom Brunel designed and built a pre-fabricated hospital for use in the field in the Crimean War.

As well as taking a bath and shouting "Eureka", Archimedes designed a screw, to pump water uphill.

Leonardo da Vinci is known for well, doing everything.

Most remarkably, he died at the age of 67, when the average lifespan at the time was around 35. I guess he was just too busy to die.

George Stephenson built the first public inter-city railway line between Liverpool and Manchester in 1830. His chosen rail gauge became a modern standard. Later in life he built deep coal mines using a technique called tubbing. And made a pile of money.

Elon Musk is most recently well known for space rockets which can land on their backsides but he made his fortune as founder of PayPal, when it was bought by eBay.

Charles Babbage is credited with the invention of the mechanical computer. He was also a writer; in his On the Economy of Machinery and Manufactures of 1832 he exposed the restrictive practices of book publishers and called them a cartel.

Thomas Alva Edison is known for development of the phonograph, the motion picture camera, and the electric light bulb, but he also collaborated with Henry Ford and David Firestone on the Edison Botanic Research Corporation, which was created to find a domestic source for organic rubber.

Clever people.