the apparatus such source being for example secured to a main frame of the apparatus the laser is for instance a co 2 type laser emitting radiation with a wavelength of 10 6 microns which is partly absorbed by the glass the beam of coherent light 10 emitted from the laser source 9 is incident on a reflecting device 11 mounted on the arm 3 and is reflected thereby along a path parallel to the longitudinal axis of that arm onto a second reflector 12 which is attached to the scoring tool carriage 4 the reflector 12 reflects the beam 10 onto the glass ribbon via an optical lens 13 which focuses the beam on the line which has just been scored by the tool 8 this focusing may be approximate since it is unnecessary for the beam to be accurately focused on the score line to effect the required severance of the glass ribbon tests showed that 1 millimeter of glass thickness was cut at a relative speed of 95 mm per second i e approaching 6000 mm per minute between the focused beam and the glass these results were obtained with power reduced by at least 50 in comparison with the power required when using the known laser beam cutting technique fig3 shows an apparatus in which a glass ribbon 14 is severed longitudinally at its edges while in longitudinal movement on a roller conveyor 15 the glass ribbon.