C15 Tŵr Awyr Based off of the ubiquitous Caquot dirigible, the air tower is a tethered kite balloon with five chambers (consisting of the main hydrogen lift chamber, an internal air balloonette to provide some measure of trim which can be filled from the main chamber, and three air "lobes" designed to be able to catch the wind and thus inflate, stabilizing the craft, at the whim of the pilot) designed for a crew of two(although with capacity for up to five) on land or at sea. These crew are equipped with a number of devices to better observe and report on enemy movements, including mounts for a telescopic camera, a specially modified radio optimized for aerial use, a backup telegraph for when the radio conks out or the use of in inadvisable, and finally a set of small message tubes for emergencies or for sending down drawings.
The tether itself(attached to the craft via a swinging yoke system) serves five purposes, securing the craft, acting as a stringer line for a telegraph cable, acting as a stringer line for the electrical cable used to power the onboard radio, doing the same for the (third-level backup) message line, and grounding the craft electrically.
Of course, some effort is also made to procure parachutes for the crews.
Coloration is less important(mostly due to distance, ineffectual of enemy fire until/unless they design explosive or incendiary rounds they can get on an aircraft), although there are notes for a white underside and a mottled green with white upper as a sort of camouflage.
-edit to respond to Doom-
Observation balloons are fairly safe, fairly simple techs that have no end of utility,to the point where they are still being used today in Afghanistan. Recon aircraft are great for taking photos behind enemy lines, but are useless for artillery spotting until we can shove light, reliable radios in them(as noted in the main thread by Joe) . Plus they are alot easier to use on naval ships, and I am sure that crew of the "battleship" would love to have their effective range helped out by their own kite.
-edit of muchlater-
For some reason, I thought it was 1914 in game. Fixed that then.