"The judicial Power shall extend . . . to all Cases of admiralty and maritime Jurisdiction."

"The Congress shall have Power . . . To make all Laws which shall be necessary and proper for carrying into Execution . . . Powers vested by this Constitution in the Government of the United States."

These clauses of the Constitution of the United States provide the foundation for the exercise of jurisdiction in admiralty causes by the federal courts. The recent decision of the United States Supreme Court in the case of The Thomas Barlum, upholding the constitutionality of the Ship Mortgage Act, 1920, provokes inquiry into the question of how far Congress may extend the admiralty jurisdiction of the federal courts without running afoul of the inherent limitations of the Constitution.