Candela frequency and that has a radiant intensity in that direction of watt per steradian. The definition describes how to produce a light source that (by definition) emits one candela, but does not specify the luminosity function for weighting radiation at other frequencies. Such a source could then be used to calibrate instruments designed to measure luminous intensity with reference to a specified luminosity function. An appendix to the SI Brochure makes it clear that the luminosity function is not uniquely specified, but must be selected to fully define the candela. The candela is sometimes still called by the old name
Rosario Candela for him, one of his home and one of his son. Candela began studying cryptography in 1930 after learning about the accomplishments of the Army Signal Corps in WWI. He decrypted messages originally coded in 1898 by Commandant Étienne Bazeries of the French Army. Commandant Bazeries was "one of the most brilliant cryptologists of" his era, and he developed an encryption method considered unbreakable. Candela wrote a book, "The Military Cipher of Commandant Bazeries", in 1938 detailing how he broke Bazeries' code. Starting in 1941, Candela taught a class on cryptography and cryptanalytics at Hunter College in New York. At