A working element of an agricultural machine mounted on a substantially horizontal beam by a linking structure comprising at least one upper arm and at least one lower arm, the working element being subjected on one hand to a depth control force directed toward the ground and on another hand to a ballasting exerted by a ballasting device comprising at least one spring. One of the stages includes a variable impactor separator comprising a first chamber arranged to receive the fluid stream, and a second chamber coupled to the first chamber through an aperture to accelerate the first fluid stream. The washer has a plurality of circumferentially spaced spring fingers each extending inwardly towards the central washer opening. Through this sequential procedure of network elements, a caller can hear a sound specified by a called instead of a dry ringback tone. In one embodiment, the ARI of the fused silica article is achieved by lowering the fictive temperature of the fused silica.