It has been shown that cuprous oxide, when formed from a copper surface by suitable heat treatment, has remarkable rectifying properties towards alternating voltages applied through the oxide and copper. The purpose of our work was to investigate, the effect fully from all angles possible, and especially from those considerations affecting the constancy and permanence in the electric circuit.

The work ranged from furnace operation to tests of completed units, and further to the development of a theory explaining as completely as possible this rectifying property.

It soon became apparent, that here was ideal thesis material, and so, with proper permission, I have undertaken this rather complete report and now offer it as my thesis.

The work was carried on jointly by Mr. Rutger B. Colt, of Stevens Institute, Mr. Charles H. Bartlett of Brooklyn Polytechnic Institute, and myself. In all a period of one year and three months was devoted to this investigation, and during that time we all were largely employed directly, although other matters claimed attention occasionally.