Whenever there is no Vice President, the President of the Senate for the time being is entitled to the compensation provided by law for the Vice President.
2 U.S. Code § 6111 - Compensation of President pro tempore of Senate
(R.S. § 36.)
Section was formerly classified to section 32 of this title prior to editorial reclassification and renumbering as this section.
Compensation of Vice President, see section 104 of Title 3, The President.