Candela was chosen so that the new definition would precisely match the old definition. Although the candela is now defined in terms of the second (an SI base unit) and the watt (a derived SI unit), the candela remains a base unit of the SI system, by definition. If a source emits a known luminous intensity "I" (in candelas) in a well-defined cone, the total luminous flux "Φ" in lumens is given by where "A" is the "radiation angle" of the lamp—the full vertex angle of the emission cone. For example, a lamp that emits 590 cd with a radiation angle
Rosario Candela Italian-American architect, Gaetan Ajello. After another brief stint with the firm of Frederick Sterner, Candela set up his own practice in 1920. His first major commission was for an apartment house at West 92nd Street and Broadway. Shortly thereafter, he received his first commission for an East Side apartment at 1105 Park Avenue. During the next five years, Candela designed a number of residential buildings on the Upper West Side, primarily on West End Avenue and Riverside Drive. During this period, the West side was undergoing an intense transformation from an area of primarily single-family homes to one characterized by