A diameter overshot wheel powered spinning mules and jennies. Mammoth jennies are taller than , and mammoth jacks and geldings over . The stallions are often crossed with female donkeys (Jennies) to produce hinnies. The Squadron flew de Havilland observation biplanes and Curtiss JN-4 "Jennies". Flying training was begun with eighteen Curtiss JN-4 Jennies. UCM's athletic teams are called Mules (men) and Jennies (women). Curtiss JN-4D Jennies and also deHavilland DH-4s. Jacks average in height, and jennies . The volume ends at a party Jenny has arranged between the past Jennies and Doctors. Minimum height is for jacks and for jennies. Curtiss JN-4 Jennies became a common sight over Long Island in 1917 and 1918. The beginning class in March of that year was the first without Jennies. The jennies required skill but were inexpensive and could be used in a home.