the spout relative to axis o this angular position corresponds to the angle between lever 58 and axis x 39 thus position sensor 160 provides output signals commensurate with the pivoting movements of spout 24 about axis x similarly sensor 162 will provide output signals commensurate with the rotation of fork 26 and thus also of spout 24 about axis y fig9 and 10 schematically represent a control mechanism including a control device 166 which can be located in any desired position such as for example in a control room the control device 166 is actuated by a suitable drive mechanism 168 which may be similar to the mechanism described above in the discussion of fig1 or one of the other different constructional versions thereof as described in co pending application ser no 288 974 the control device 166 as schematically illustrated in the drawing is supported on a suitable frame 172 by means of a universal joint system which as shown in fig1 will be a cardan type joint which has been indicated generally at 170 the universal joint 170 enables the control device 166 to pivot about perpendicular axes x 1 and y 1 the axes x 1 and y 1 of course correspond respectively to the pivot axes x and y of spout 24 in furnace head 20 the movements of control device 166 for example a conical precession movement will be monitored and employed to provide instructions for the desired movements of the spout these instructions will be in the form of control signals which represent the angular movements of control device 166 about axes x 1 and y.