A ZEPPELIN LEAVING ITS SHED FOR A LENGTHY FLIGHT—A Zeppelin airship can be steered in two-ways—either by static or by dynamic means. Steering by static means is effected by descending a portion of the water ballast that is carried, when the airship becomes lighter and ascends, or by allowing the escape of portion of the hydrogen gas, when the airship becomes heavier and descends. Steering by dynamic means is effected upwards and downwards, by operating the horizontal rudders. As the airship is driven forward through the air these rudders act as planes, causing the airship to rise or descend, according to the position of the rudders. In this case neither gas nor water ballast need be expended.

New Zealand Illustrated Sporting & Dramatic Review, Issue 1361, 25 May 1916, Page 35

A ZEPPELIN LEAVING ITS SHED FOR A LENGTHY FLIGHT —A Zeppelin airship can be steered in two - ways—either by static or by dynamic means. Steering by static means is effected by descending a portion of the water ballast that is carried, when the airship becomes lighter and ascends, or by allowing the escape of portion of the hydrogen gas, when the airship becomes heavier and descends. Steering by dynamic means is effected upwards and downwards, by operating the horizontal rudders. As the airship is driven forward through the air these rudders act as planes, causing the airship to rise or descend, according to the position of the rudders. In this case neither gas nor water ballast need be expended.