The first harvesters were dragline machines brought in by the early Imperial ecologists. The factory was anchored in place with two towers of the harvester established approximately 500 meters from the factory, 100 meters apart. A large drag-scoop was attached to a line leading directly to a winch on the factory. To die back of die scoop was attached the haul-back line which was run through a pulley on the first tower, through a pulley on the second tower, then back to a second winch on the factory. Harvesting of the spice was achieved by dragging the scoop to the factory through die sand, filling it as it progressed. The scoop was emptied and "hauled back" by the haul-back line to take another scoop. When one drag location was exhausted, the towers were moved around the factory until a circular area was mined. This method was very slow and had several negative side effects. The noise of the drag always called a worm, and the towers and drags would be tost when the factory was evacuated. Furthermore, the depth of a drag could not be well controlled, causing many impurities in the ore. The final and most important disadvantage was the friction-al heat generated by the drag pulling through the sand, which caused undesirable effects in the spice. The second-generation harvester was used for the longest period of time. This harvester was usually attached to the front of a factory, which in turn was mounted on a system of arms and tracks, making the harvester-factory mobile. The harvester was an inverted cone and tube leading to the factory. The cone could be adjusted for height above the sand and swung to the right or left forty-five degrees. A giant centrifugal vacuum pump SPICE MINING created an almost perfect vacuum m the cone above the sand The vacuum pulled the sand-spice ore into the harvester and to the factory The advantage of this second harvester over the drag line type was speed of mining, transport, and evacuation Profit margins increased exponentially and the safety of miners improved noticeably The problem of the heat effect OB the spice was eliminated and impurities were reduced bat new problems appeared The vacuum harvester worked well on spice in its usual sandlike state, but was ineffectual on the occasional spice-pack pockets In the case of such pockets, miners were forced to use s aiidcrawlers equipped with harrows to break up the spice-pack Once again this procedure always called a worm The most recently developed harvester to be used was designed for mining deep desert spice after the veins near the Shield Wall had been exhausted It was an aircraft which rode on an air cushion developed by a large f