Discussion on “the magnetic properties of some iron Alloys Melted in Vacuo” (Yensen), St. Louis, Mo., October 20, 1915. (see proceedings for October, 1915)

Thomas Spooner: The Burrows permeability apparatus we have used in our commercial testing for some years, and found it very satisfactory, especially when used in connection with the Grassot flux-meter. The apparatus has given us very accurate checks for the Bureau of Standards certified rods. We, of course, have not had occasion to test samples of permeability of 60,000 to 70,000, but for commercial material we feel sure that the apparatus is extremely accurate.