Abstract: A line indicating apparatus for visually monitoring changes of physical constants or functions occurring in a dynamic process. The apparatus has a plurality of units or modules which are associated with the monitoring of a corresponding plurality of variables. Each module has at least two indicating sections, each of which is provided with at least two indicating members. An electric circuit is provided for sensing the condition and changes in each monitored variable and providing various outputs to energize one or more indicating members to give a visual indication of the condition of the monitored variable. The modules are aligned with each other in a straight line so that during normal or mode "A" operation of all the variables, particular indicating sections in all of the modules will present a highly visible indicating line or band.