| In 1903 he invented the spinthariscope to detect alpha particles emitted by radioactive elements. |
| But the most striking way of showing the emanations is by the little contrivance I call a spinthariscope. |
| Leo and his friends also took the spinthariscope to an out-of-town astronomers convention and advertised that they had developed an optical system that could penetrate clouds. |
| A simple form of apparatus called the spinthariscope has been devised to show these scintillations. |
