Description (Brief): This patent model demonstrates an invention for an apparatus for type rubbing which was granted patent number It was particularly applicable to the type-dressing machine patented by Daniel Moore in Location: Currently not on view. National Museum of American History. patentee: Moore. In the model shown in Figure b, themass ofthe ring is considered. Ehrich ( ) showed an example of damage of an axial flow compressor due to rubbing and also discussed the stabilityof the backward rubbing in this model. Black ( ) obtained response curve of a forward synchronous rubbing of an unbalanced. Near the end of the discussion, Heidie had concluded that one aspect of Mark's model made sense. However, according to Heidie's analysis, the model itself was inconsistent with observations (the rubbed objects should attract one another, but Heidie's analysis led to the conclusion that they would repel according to Mark's.