Mr Mansfield misunderstood me on the subject of instruments. I requested him, as he went through Philada., to order them to be made, & to let me know the price, which I intended to remit to him. Salary cannot be advanced; it must be paid quarterly at the end of the quarter; the only exceptions are in case of officers going out of the United States, & that of the President who does not receive quarterly; and even in the last case no advance has ever been made during the present Presidency. If Mr M. had done what I requested, he would have met, however, with less embarrassment. The enclosed sketch of a letter I may send to him; but wish to know his direction & present office.

The date of his commission will not alter the time from which his salary must commence. That, in case of existing offices, always commences from the time only when the new officer takes possession of the papers &a. Till then the former officer’s salary continues; and unless you should give special instructions to the contrary which must be officially communicated to the Auditor & Comptroller, they will certainly settle the accounts in conformity to the universally received practice—