This microscope, reported by McArthur in the JRMS of 1945, very much anticipates the final form of McArthur microscope. The stage is in the middle. The condenser housing is recessed into the top and the mirror flips up from the top but stores flat against it, making both much less prone to breakage. The sliding objective changer is now controlled by two small knobs on either side of the microscope, protruding through slots, replacing the knobs at the end of the slider. This feature could also break easily and was abandoned in favor of the earlier method.