Officers of the United States, appointed for the term of four years, but removable at the pleasure of the president. Act of May 15, 1820, sect. 1, 3 Story’s U. S. Laws, 1790. 2. The duties of a collector of customs are described in general terms, as follows: He shall receive all reports, manifests and documents, to be made or exhibited on the entry of any ship or vessel, according to the regulations of this act shall record in books, to be kept for the purpose, all manifests; shall receive the entries of all ships or vessels, and of the goods, wares and merchandise imported in them; shall, together with the naval officer, where there is one, or alone, where there is none, estimate the amount of duties payable thereupon, endorsing the said amounts upon the respective entries; shall receive all moneys paid for duties, and shall take bonds for securing the payment thereof; shall grant all permits for the unlading and delivery of goods; shall, with the approbation of the principal officer of the treasury department, employ proper persons as weighers, gaugers, measurers and inspectors, at the several ports within his district; and also, with the like approbation, provide, at the public expense, storehouses for the safe keeping of goods, and such scales, weights and measures, as may be necessary. Act of March 2,1799)