Dry nurse

when an inferior officer on board ship carries on the duty, on account of the captain's ignorance of seamanship, the junior officer is said to dry-nurse  his captain. Majors and adjutants in the army also not unfrequently dry-nurse  the colonels of their regiments in a similar manner. The sergeant who coaches very young officers, is called a “wet nurse.” The abolition of purchase has, however, considerably modified all this.