31. His prime example are traces in a cloud chamber to which he devotes the penultimate chapter of the book. 32. Cloud chambers work on the same principles as bubble chambers, but are based on supersaturated vapor rather than superheated liquid.33. Some of Drury's lasting works are " cloud chambers ", darkened caverns constructed of local rock, turf, or other materials. 34. Opera singers are sometimes like subatomic particles bumping about in a cloud chamber as they proceed on their determined paths. 35. Cloud chambers in particular can be built from widely available materials and can be constructed even in a high-school laboratory.36. The muons can be easily detected by many types of particle detectors, such as cloud chambers , bubble chambers or scintillation detectors. 37. At the request of Patrick Blackett, who was working with cloud chambers , Bethe created a relativistic version of the Bethe formula. 38. In the cloud chamber , it is the clusters of ions caused by a passing high-energy particle that acts as nucleation centra. 39. To study the new elementary particles, Bridge and Martin Annis operated a large rectangular multi plate cloud chamber at Echo Lake. 40. Walther Bothe gave the duo the idea of considering photographic emulsion as a continuously active cloud chamber to register and store tracks.