Bridge graphic
Used for conducting coolant, the primary manifold was a component of the USS Enterprise's intermix chamber in 2266. A graphic on the bridge monitored the temperature of the coolant in thousands and hundreds of degrees in the left and right primary manifolds. When, in that year, the Enterprise was breaking itself free from the tractor beam emitted from an alien pilot vessel, this graphic displayed the increasing temperature in the manifolds, close to the point where the chamber would break apart from the strain. (TOS: "The Corbomite Maneuver")