Posted 3 years ago
I need help identifying this item. It is 2 feet tall and 8 inches in diameter. The tube rotates on bearings around the cast aluminum frame. The tube is marked across the top in centimeters. The numbers down the scale reduce as you go down each horizontal line. The closer to the bottom the faster the reduction in the number. The farther around the drum and more centimeters around the drum the numbers also reduce faster. It appears to by like some type of slide rule. I would like to know for what purpose. Thank you to all who can help with identification.