Case material: Steel; Charge: Automatic; Conditions: New Presentation condition : With dealer guarantee ; Model: Heritage Price on request Gmtbroker Reference: L2.780.4.18.2 Longines L2.780.4.18.2 Complete Details: TELEMETER & TACHOMETER CHRONOGRAPH: The TELEMETER SCALE was devised to calculate distances based on speed of sound - this requires both visual & audible observations. To calculate the distance of a specific event one must start the chronograph as soon as the visible event starts and stop the chronograph as soon as the audible is heard. The large central hand will then point to the kilometer scale on the dial edge to show the distance the event took place. Back in the day the TELEMETER function was used in war  as a crude rage finder to calculate the enemy artillery distance: when the muzzle flash was seen, the chronograph was started and when the firing was heard, the chronograph was stopped - the seconds hand pointed to how far away the enemy was situated:  This watch features: Polished stainless steel case. Black alligator leather strap with white top-stitching. White lacquered dial. Black painted Arabic Numeral hour markers. Blue steel hands. Two red printed scales on the watch: TELEMETER Kilometer distance on the dial perimeter. TACHOMETER scale at the dial center.  Chronograph/Stopwatch functions: Column wheel chronograph - column wheel viewable  via the transparent case back in blued steel. Large central seconds hand counter. 30-minute counter at th