The practice of making such appointments, whether in a vacation or during the session of Congress, has been constantly followed during every Administration from the earliest period of the Government, and its perfect lawfulness has never to my knowledge been questioned or denied.  Without going back further than the year 1829, and without taking into the calculation any but the chief officers of the several Departments, it will be found that provisional appointments to fill vacancies were made to the number of 179 from the commencement of General Jackson’s Administration to the close of General Pierce’s.  This number would probably be greatly increased if all the cases which occurred in the subordinate offices and bureaus were added to the count.  Some of them were made while the Senate was in session; some which were made in vacation were continued in force long after the Senate assembled.  Sometimes the temporary officer was the commissioned head of another Department, sometimes a subordinate in the same Department.  Sometimes the affairs of the Navy Department have been directed ad interim by a commodore and those of the War Department by a general.  In most, if not all, of the cases which occurred previous to 1852 it is believed that the compensation provided by law for the officer regularly commissioned was paid to the person who discharged the duties ad interim.  To give the Senate a more detailed and satisfactory view of the subject, I send the accompanying tabular statement, certified by the Secretary of State, in which the instances are all set forth in which provisional as well as permanent appointments were made to the highest executive offices from 1829 nearly to the present time, with their respective dates.

It must be allowed that these precedents, so numerous and so long continued, are entitled to great respect, since we can scarcely suppose that the wise and eminent men by whom they were made could have been mistaken on a point which was brought to their attention so often.  Still less can it be supposed that any of them willfully violated the law or the Constitution.

The lawfulness of the practice rests upon the exigencies of the public service, which require that the movements of the Government shall not be arrested by an accidental vacancy in one of the Departments; upon an act of Congress expressly and plainly giving and regulating the power, and upon long and uninterrupted usage of the Executive, which has never been challenged as illegal by Congress.

This answers the inquiry of the Senate so far as it is necessary to show “how and by whom the duties of said office are now discharged.”  Nor is it necessary to explain further than I have done “how, when, and by what authority” the provisional appointment has been made; but the resolution makes the additional inquiry “why the fact of said appointment has not been communicated to the Senate,”