The outer, and largest, bronze basin is decorated in zodiac signs which sit in their "correct astrological position for the sun's rays."

The small basin serves as the venue for a 20 foot[4] tall water spouting jet.

[1] The inscription on the bench reads: "It sits like an island, traffic whizzing by on the three major arteries."

[7] Its creation was authorized by Congress on July 16, 1947 by the Joint Resolution 1701:[1] Resolved by the Senate and House of Representatives of the United States of America in Congress assembled, That the Secretary of the Interior is hereby authorized and directed to grant authority to the Andrew W. Mellon Memorial Committee to erect a memorial fountain on public grounds in the vicinity of the intersection of Pennsylvania and Constitution Avenues, in the District of Columbia, such grounds being now owned by the United States: Provided, That the design and location of the memorial shall be approved by the National Commission of Fine Arts and the National Capital Park and Planning Commission, and the United States shall be put to no expense in or by the erection of this memorial: Provided further, That unless funds, which in the estimation of the Secretary of the Interior are sufficient to insure the completion of the memorial, are certified available, and the erection of this memorial begun within five years from and after the date of passage of this joint resolution, the authorization hereby granted is revoked.

[9] The Aries zodiac faces directly east with the Libra symbol facing west and the Virgo symbol arranged along Pennsylvania Avenue, leading to some believing that Masonic influences were essential in the architecture.