An apparatus applies mesh from a roll to a face of a mine passage. The apparatus pivots about a fixed member to swing in gate-like fashion during transport. 5, and displays the X-ray diffraction values given in Table 1, and a method of preparation of the material in the presence of fluoride ions and using N-methylsparteinium as structure director agent; the material being useful in its acid form and in bifunctional catalyst form in processes of catalytic cracking, hydro-cracking and alkylation of aromatics. The first conical surface of the lens tube and the second conical surface of the mounting base can cooperate with each other, so as to prevent dust contamination and to make the central axis aligned with the optical axis. The tab member has a lower surface.