*Duties of Balloon Crew.* Each kite balloon carries aloft two observers, Fig. 28, both of whom can concentrate their entire attention on the work of "spotting," since they have nothing to do with the control of the balloon itself, except to give orders. Their chief duties consist of "counter-battery" observation, that is, spotting the location of enemy batteries, and being constantly alert to detect any suspicious movements back of the enemy’s lines, such as movements of troops, ammunition, or supplies. The batteries controlled from observation balloons are the "heavies," which are located 1 mile or more back of the front line trenches and to the gunners of which the objects they are firing at are never visible. Some of the heaviest guns mounted on specially constructed railway trucks are often fired from points 5 miles or more back of the lines. In fact, when balked in their attempt to take Calais, the Germans bombarded the town with the aid of long-range naval guns from a distance of over 15 miles and every shot dropped into either some part of the city or its outskirts. Buildings, hills, or specially constructed and concealed observation towers are frequently utilized in conjunction with captive balloons to serve as auxiliary observation posts, so that the base line connecting the two may be used to triangulate distances and thus calculate them more accurately than is possible by direct observation from a single point. [Illustration: Fig. 28. French Kite Balloon Observers about to Ascend _Copyright by Committee on Public Information, Washington, D.C._] *Risks Incurred.* _Enemy Fire._ While the observers in a kite balloon are not subjected to all the risks that the aviator must encounter when he goes aloft or, at least, not to the same extent, their lot is far from being free from danger. One of the duties of the reconnoitering aviator is to destroy observation balloons by means of incendiary bombs equipped with fishhooks which catch in the fabric or by the use of his machine gun. Enemy batteries may also succeed in getting the range of the balloon and fire at it with large caliber shrapnel, which spreads its fragments over an area 100 yards or more in diameter when it bursts. So many of the German balloons were downed by French and British aviators in the early part of the war—and the Germans retaliated in kind—that a battle plane is now always detailed to keep watch above the balloon to ward off attacks by aeroplanes.