Early use was to compare the color of a blood sample with the color of a standard. The eyepiece allows the viewer to see half of one side and half of the other by way of a pair of prisms or one cut just right.The samples are raised and lowered until both views look the same color. The instrument then has numbers so as to see a ratio and that gives an answer such as the red blood count. On this, I do not see the sample tubes. You now know how it is used, you might figure it out.
Light must come in evenly. There is no magnification involved. The rod that does not move is just stuck, usually by corrosion. Spectrometers now do this work including much more.From Elli Buk, he had a shop and an amazing collection, google him. I PACK well and fast, check my feedback for any concerns, why not join the family of happy winners.
The scale shown behind the item is in inches so you can tell the size of the object. LOCATION-- box (white Perma Stor-all BUK STUFF then in black box) ------127. This item is in the category "Antiques\Science & Medicine (Pre-1930)\Scientific Instruments\Other Antique Science Equip". The seller is "syottoys" and is located in this country: US.
This item can be shipped worldwide.