If it swung down close, it might riddle the bag with machine gun bullets but without necessarily sinking it—as witness the case of Trotter’s ship in Oklahoma leaking gas for 72 hours from 14 gaping holes and still able to fly 400 miles for repairs. The plane would have almost to cut the blimp in two with a spray of bullets to destroy it—if it chose to use its precious far-borne ammunition in such fashion—and would find it better to attack from below, on the chance of a lucky hit into the airship structure or controls, or one which disabled its crew. But in that event the airship, also armed, shooting it out from its more stable gun platform above would have as good a chance as the plane. The airship is vulnerable—as are all other military craft—but used as the Navy proposes to use airships, it may be said to have an acceptable degree of vulnerability, in view of its potential usefulness in its special field—defense against submarine attack on convoys or coastwise shipping. The airship’s advantages have been pointed out, but may be repeated. These grow out of its speed range, from zero to a maximum of 65 knots or so. Its slow speed, as compared to the airplane has the compensation that it does not have to circle around to maintain altitude, can keep any suspect object under continuous observation. Its high speed enables it to reach a given point much sooner than the fastest surface scout. [Illustration: Barrage balloons—spiders who spin out webs of steel as they ascend—but these spiders are out to catch fliers, not flies, enemy fliers who threaten our democracy.] [Illustration: Modern armies towing a few of these pocket sized barrage balloons along, might not be too much concerned over attacks by strafing airplanes.] [Illustration: This Strata Sentinel will fly at 15,000 feet, twice the height of other barrage balloons. By that time the lobes will be completely filled out by expanding pressure of the lifting gas.] [Illustration: This airship, silhouetted against the afternoon sun might be pacing a peaceful cruiser race through the surf off Long Beach, on the Southern California coast. Or it might be leading units of the mosquito fleet to sea off Cape Cod, to hold an enemy U-boat in check till ships of heavier armament could arrive.] [Illustration: Helium-inflated, fast, long ranged, the modern K-type Navy patrol ship is a far cry from the primitive airships of World War I. They are armed with bombs and machine guns.] [Illustration: In brilliant sunshine, or overcast, in fog or rain or snow, the blimps take off from their bases day after day, on guard against any enemy who may invade the coastal waters. A faint smoke screen, miles distant over the endless waters, may turn out to be a peaceful merchantman—or a vessel with grimmer purpose, seeking the advantage of surprise attack.] [Illustration: Airship over cargo ship]