Section 17, R.S. Sec. 3745, provided that an affidavit be affixed to the return of contract required by section 16 of this title.

Section 18, R.S. Sec. 3746, provided punishment for failure to make returns of contracts as required by sections 16 and 17 of this title.

Section 19, R.S. Sec. 3747, imposed duty on Secretaries of War, Navy, and Interior to furnish officers with letters of instruction relating to their duties under sections 17 and 18, contract forms, and affidavits, to insure uniformity