This Facile Cast Iron milk and Cream Test Separator came out of a antique shop that closed and is in good looking and working condition. The top of this piece is black cast iron and hinged at the top to view the 6 cups inside. The unit cranks smoothly and all cups and internal parts are present and in good condition. D. H. Burrel Babcock testers are embossed FACILE. This unit measures 18"x11"x18" and weighs 55 lbs. What makes this a great find is that it has the book with it. I have not seen another with the book. A little history: Most of the value of the milk was in the cream or milk fat. However the milk fat was a very small fraction of the milk, usually between 3-7%. Assuming all milk was equal was not a safe assumption. Just because one cow gave more milk did not mean that cow was making more money. The dairyman needed to know the fat content of the milk so he could feed and mange his cows properly. In fact this 1904 advertisement warns of robber cows, cows that eat their share but don't produce much butterfat. Likewise creameries could not just buy milk based on volume. Dishonest dairymen could add water or skim some of the cream off prior to selling it. Creameries also needed to know the fat content of the milk they were buying. Tests therefore were needed. In 1890, S. M. Babcock wrote a paper detailing an economical and practical test to measure milk fat that could be run on the farm or in the lab. His method entailed mixing a small amount of milk with an equal amount of sulfuric acid and then centrifuging the mix in special glass vials with a thin graduated neck. The acid would digest everything but the fat. Since the fat was less dense it would rise to the neck of the vial and could be measured. Spinning the samples in a centrifuge would speed up the separation. This test became known as the Babcock Test. Picking up on this idea Harvey Feldmeier of Little Falls, New York, issued a patent on April 10, 1900 for a large cast iron milk tester that was hand cranked. Feldmeier assigned both of these patents to D. H. Burrel and Company, also in Little Falls, New York. ATTENTION SHIPPING WILL BE A LITTLE HIGHER DUE TO HAVING TO CRATE THIS ITEM. TO HEAVY TO SHIP IN A CARDBOARD BOX.