Geodimeter 6

21 inches high, 14 inches wide, 8.5 inches deep

Description:
The Geodimeter Model 6, introduced in 1964, was a transistorized instrument with coaxially mounted transmitter and receiving optics. It had a range of 1-2 miles in daylight, and 10 miles in darkness, and a standard accuracy of 5 mm + 1mm/km. Without case or tripod, it weighed a mere 35 pounds. Advertisements showed it being carried by a woman, with text stating "Your assistant can look like this." Equipped with a tungsten lamp and various accessories, it cost approximately $10,000 and could be powered with a 12-volt car battery. A mercury vapor lamp for the Model 6 cost some $2,500 more, and required a special generator.

History & comments
The Geodimeter (acronym for geodetic distance meter) was the invention of the Swedish Physicist Dr. Erik Bergstrand who designed and applied it to the measurement of the speed of light over measured distances in 1947. His original device, introduced in 1949, weighed more than 100 kilograms and was the very first EDM instrument ever made.