41 Education and training, namely, conducting classes, seminars and workshops in the field of development, planning, installation, use, maintenance and repair of machines for coating, covering, thickening, vulcanising, impregnating, washing, colouring, stretching, fixing, stamping and hot-pressing lengths of material, in particular of textiles, paper, plastic and metal, and of apparatus for heating, steam generating, refrigerating, ventilating, water supply and drying purposes, in particular machines for drying lengths of material, in particular of textile, paper, plastic and metal