Hardinge Conical Mill Co
1918 "The Hardinge Conical Mill is the invention of Mr. H.W. Hardinge and has been fully patented by him. It has been used successfully in the grinding of ores, limestone, phosphate rock, feldspar and talc. The purpose of the tests in this thesis was to determine the worth and adaptability of the Conical Mill for the preliminary grinding of cement clinker and to determine the relative merits of this type of grinder as compared to the roll type of grinder. The tests herein were performed under the direction of the writer assisted personally and through correspondence by Mr. H.W. Hardinge of the Hardinge Conical Mill Co. While conclusive results have not been determined, the main results have been attained and further testing will be in the nature of adjusting and designing suitable screening and feeding devices."[1]