The Barber design with large head showing both obverses side by side. Harry Bass was the first to notice that two obverse dies existed per Pollock.
The first was used only on a single silver example of J1524/P1692 and a single copper example of J1525/P1693 both of which were formerly in the Bass Foundation collection. This die has the date and head low with less finishing in the leaves atop Liberty's head.
The second used on both silver example of J1524/P1690 and copper examples of J1525/P1691 has the date higher and more fine lines extruding from the leaves above Liberty's head.
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Photo courtesy of Saul Teichman.