Balloon observation, and instructions on the subject of work in the basket

by United States. War Department. Division of Military Aeronautics

PRACTICAL ADVICE.

1. Work sitting down, with the map on your knees and leaning against the edge of the basket.

This position is preferable to all others, because it allows the observer—

(a) To correct with his head and shoulders the movements of the basket.

(b) To have the map always before him. He can consult it at any moment, mark the necessary alignments without loss of time, use it as a desk for drawing or taking notes, or as a wind shield when looking at photographs.

The observer who works standing up must either pick up his map from the bottom of the basket every time he needs it, which is out of the question, or fasten it outside the basket; the latter solution is inadvisable, it necessitates working in the wind when the map is referred to, and every time the observer turns to look at his map he disturbs the equilibrium of the basket.

It is advisable to work standing up only on days when there is practically no wind, and the balloon is continually turning and never becomes oriented.

2. Have always within reach a flat rule, a pencil, and a duodecimeter rule.

To be able to trace an alignment on the map with precision, the rule must rest on a firm surface. This happens when the map is mounted on a drawing board; when it is mounted on a frame with rollers, the frame should have, between the two thicknesses of the map, a board level with the edges of the frame on which the rule can slide with its whole length on the map.

With a hard pencil, well sharpened, precise and neat alignments can be drawn.

The duodecimeter rule is for measuring distances on photographs and on the map; chiefly in observations of fire.

3. Hold the field glasses with both hands.

This advice, sometimes ignored by observers without expedience, has a great influence on the accuracy of information. When an observer holds the glasses in one hand, it is much more difficult for him to correct the movements caused by the balloon and to concentrate on a point. It is very important, therefore, to hold the glasses firmly with both hands, especially when you are making a delicate observation or when you wish to study an “objective” in detail.

PART III.
APPENDIX.

Note 1.—All observations of rounds refer to the line battery target (b-t) and a line perpendicular to same passing through the target. Observations are given in meters right and left and whether the round is over or short. Indications as to deflection are given before those of range. Indications as to the amount of error precede those as to the sense of the error. Example, 50 meters “Right,” “over.” Owing to the dispersion of fire when adjusting fire for field artillery or howitzer, it is unnecessary and of little value to the battery to give the amount of the error in range except when asked for by the battery commander or when the error in range is abnormal (over 200 meters).

When the target is clearly visible and the effect of a round hitting a target is evident, the observation “Target” is reported. Unless the observer is certain of having seen the bursts “Unobserved” will be sent. If, however, after a few seconds smoke can be seen rising from trees, houses, etc., in proximity to the target, the observation “Unobserved, but smoke seen rising left and over,” may be given.

Note 2.—Observers must beware of being over-confident in their own powers of observation. True confidence only comes with experience, and this is best attained by making ascents with a trained observer when ranging a battery and checking one’s own observations with those given by him. An observation must never be given unless the observer is quite certain as to its correctness. It is essential to good results that the artillery may be able to rely absolutely on the observations sent down. The observer must watch the target but must avoid straining his eyes by putting up his glasses as soon as a round is fired. He should arrange for the chart room to inform him when a shell is about to fall. The latter must know the time of flight. Observers must learn to distinguish readily the bursts of different kinds of shells.

Note 3.—If the balloon-target line makes an angle with the battery-target line of more than 30° with field artillery and 20° with heavy, the balloon position will be given to the battery, and all observations will be given with reference to the balloon-target line and the battery will replot accordingly.