Krypton n. (Chem.) An inert gaseous element of the argon (noble gas) group, of atomic number 36, occurring in air to the extent of about one volume in a million. It was discovered by Ramsay and Travers in 1898. Boiling point, -152.3° C.; melting point, -156.6° C.; symbol, Kr; atomic weight, 83.8.
... numbers—1:4:7:—2:4:6:—7:5:3, and so on; for he is running by his tanks only, lifting or lowering her against the uneasy air. All three engines are at work, for the sooner we have skated over this thin ice the better. Higher we dare not go. The whole upper vault is charged with pale krypton vapours, which our skin friction may excite to unholy manifestations. Between the upper and the lower levels—5,000, and 7,000, hints the Mark Boat—we may perhaps bolt through if.... Our bow clothes itself in blue flame ... — With The Night Mail - A Story of 2000 A.D. (Together with extracts from the - comtemporary magazine in which it appeared) • Rudyard Kipling