Some of the 1971-D pieces exhibit a variety in which (among several differences) the eagle lacks brow lines, these have been dubbed by Eisenhower dollar specialists the "Friendly Eagle Pattern". The 1972 dollar struck at Philadelphia is broken down into three varieties, which were made as Gasparro adjusted the design to take advantage of better steel being used in the Mint's dies. A midyear change in the design was announced by Brooks at the American Numismatic Association's 1972 convention in New Orleans, although she did not state exactly what was being changed. The three varieties may be differentiated by examining the depiction of the Earth on the reverse. Type I dollars show the Earth somewhat flattened, Florida pointing to the southeast, with the islands mostly to the southeast of the tip of the peninsula. The Earth is round and Florida points to the south on the Type II, with a single, large island to the southeast. The Type III is similar to the Type II, except that there are two islands directly to the south of the peninsula. The Type II is from a single reverse die, used in March 1972, and erroneously placed in service at Philadelphia—it is identical to and should have been used for the silver proof strikes at San Francisco. The Type III was placed in service, replacing the Type I, in September 1972. The Type I is most common; the Type III design was used in 1973 and after. The 1972 Type II is expensive in top grades, as is the 1776–1976 Type I from Philadelphia, which was only available in mint sets.