X-rays

X-ray machine voted most important invention in Science Museum poll - Times Online:

Russell Reynolds had only one wish when in 1896 at the age of 15 he learnt of the discovery of X-rays: to possess his own X-ray machine.

The Westminster schoolboy enlisted the help of his father, John Reynolds, a GP, and set about building one. Within a year the machine was finished, and it is now displayed in the Science Museum in London.

Yesterday Reynolds’s pioneering spirit gained further recognition as the X-ray machine was voted the most important invention in the history of science. In a museum poll nearly 50,000 people voted on ten inventions and discoveries, which included penicillin, the Pilot ACE computer and Stephenson’s Rocket. The X-ray machine was a clear winner, with 9,581 votes.

Although I am not a scientist and therefore am probably wrong [smirk], I would allow that the x-ray machine is the greatest scientific invention of the 19th century.  However, my opinion is still that the greatest scientific invention of all time is the transistor.  Just remember how many great inventions that are in common use today would not have been possible without it.