Here is an extremely rare Gurley Drainage Level that fit upon a Jacob's staff. This was made at the beginning of the 20th century at the Gurley factory in Troy, NY. There are very few of these left in the world today. In fact, the Gurley Museum in Troy, NY does not have one, nor does the Smithsonian in Washington D.C.  An avid collector told me that that they are very rare and that he had only seen one in the Gurley catalog of 1905. The curator of the museum in Troy wished to acquire it, but only accepted donations. He said that the Smithsonian also would like to acquire it, but under the same circumstances. I wish to sell it. It is 7 1/2" X 2 1/4" X 1 3/8" and weighs 2 lbs. 11 oz. A great topper for any collection. The display case shown with it, is included. It will be carefully packed and insured.