_c. Recoil._ Stability must be sufficient to withstand the recoil from the gun. If possible, the firer should hold the gun snugly against his right side to support it and to absorb its recoil. _d. Protection._ Full advantage should be taken of cover and concealment, such as shell craters and vegetation. 25. AIMING. _a. Sighting._ There are no sights on the gun because of the short range from which it is fired, the variety of fuels used, and the marked effects of wind. (Par 23) _b. Fortifications._ When firing at a fortified position, flame must be directed _into openings_ (gun ports, firing slits, ventilation screens, doorways). Flame inside gives the desired effects, but flame on the outside has little effect on personnel within. _c. Thickened fuel._ (Figs 3 and 20) When firing at or near maximum range, it may take several seconds for a burst of thickened fuel to carry through the air to the target area. Short bursts may result in misses at long range for this reason. Skill in aiming is particularly important with thickened fuel. _d. Liquid fuel._ With liquid fuel, the greatest effect may be obtained by placing the flame directly on the target. (Fig 21) [Illustration: Fig 20. Thickened fuel flame hitting and clinging to target. Fuel burns for several minutes.] [Illustration: Fig 21. Flame (liquid fuel) hitting target.] 26. FIRING. With pressure-tank valve open: _a. Pull trigger._ Pull the trigger rapidly and vigorously. A flash should appear at the front of the gun. This shows that an incendiary charge of the ignition cylinder has been ignited. Release the trigger. (If the flash does not appear, pull the trigger again, or as often as necessary up to five times, until a flash appears.) _b. Squeeze fuel valve._ Immediately after pulling trigger, compress the valve lever and grip safety vigorously with the right hand. Burning fuel will be propelled from the gun. _c. Adjust fire._ Direct the flaming fuel at the target. Continue to squeeze the valve lever and grip safety throughout the burst. When thickened fuel is fired, follow the fuel with eyes to the side of the stream in order to observe and correct aim. (If eyes are directly behind the stream, the flame may obscure the target.) 27. CEASING OR INTERRUPTING FIRE. To cease or interrupt firing, release the controls. 28. ADDITIONAL BURSTS. To fire additional bursts, repeat procedure followed in Paragraphs 26 and 27, keeping in mind that there are five incendiary charges in the ignition cylinder and that the total firing time, not including time between bursts, is approximately 8 to 9 seconds. Each of the five incendiary charges in the ignition cylinder burns for from 8 to 12 seconds. 29. SOAKING THE TARGET. When liquid fuel is used, it may be desirable to soak the target with fuel first and ignite it afterward. To do this, fire one or two short bursts without pulling the trigger. Then follow with an ignited burst, as in Paragraph 26. 30. AFTER FIRING.