The smaller bell can give more appropriate tone in the higher range of the instrument.
Conn company in the United States[1] Other major U.S. brass-instrument manufacturers soon began production of similar instruments.
The instrument was first popularized by Italian-born euphonium virtuoso Miguel Raffayolo, soloist with the Patrick Gilmore band, documented in American newspapers by 1880.
About the second bell, famous euphonium soloist Arthur W. Lehman once said during a Marine Band concert, "We use it to hold our white gloves when we are not wearing them.
While part of the Sousa and Pryor Bands, Simone at times favored the double-belled euphonium and he even composed "Priscilla" (in tribute to Jane Priscilla Sousa), a double-bell euphonium solo.