An adjustable ground clamp for easy positioning onto electric conduits of different diameters and grounding multiple electrical devices. The preferential oxidation step includes contacting a fuel stream comprising hydrogen and carbon monoxide in the presence of an oxygen at a preferential oxidation temperature of between about 70 and about 160 C. In order to move the glass sheets and the glass sheet shapes into contact with the contact edges the tables I, II are aligned sloping down toward the contact edges so that the glass sheets and glass sheet shapes slide on air cushions produced between the glass sheets or glass sheet shapes and the tables in contact with the contact edges.