History of the Expedition under the Command of Captains Lewis and Clark, Vol. I. | Page 5

such aids as the secretary at war can yield in his department; and from him also you will receive authority to engage among our troops, by voluntary agreement, the number of attendants abovementioned; over whom you, as their commanding officer, are invested with all the powers the laws give in such a case.
"As your movements, while within the limits of the United States, will be better directed by occasional communications, adapted to circumstances as they arise, they will not be noticed here. What follows will respect your proceedings after your departure from the United States.
"Your mission has been communicated to the ministers here from France, Spain, and Great Britain, and through them to their governments; and such assurances given them as to its objects, as we trust will satisfy them. The country of Louisiana having been ceded by Spain to France, the passport you have from the minister of France, the representative of the present sovereign of the country, will be a protection with all its subjects; and that from the minister of England will entitle you to the friendly aid of any traders of that allegiance with whom you may happen to meet.
"The object of your mission is to explore the Missouri river, and such principal streams of it, as, by its course and communication with the waters of the Pacific ocean, whether the Columbia, Oregan, Colorado, or any other river, may offer the most direct and practicable water-communication across the continent, for the purposes of commerce.
"Beginning at the mouth of the Missouri, you will take observations of latitude and longitude, at all remarkable points on the river, and especially at the mouths of rivers, at rapids, at islands, and other places and objects distinguished by such natural marks and characters, of a durable kind, as that they may with certainty be recognised hereafter. The courses of the river between these points of observation may be supplied by the compass, the log-line, and by time, corrected by the observations themselves. The variations of the needle, too, in different places, should be noticed.
"The interesting points of the portage between the heads of the Missouri, and of the water offering the best communication with the Pacific ocean, should also be fixed by observation; and the course of that water to the ocean, in the same manner as that of the Missouri.
"Your observations are to be taken with great pains and accuracy; to be entered distinctly and intelligibly for others as well as yourself; to comprehend all the elements necessary, with the aid of the usual tables, to fix the latitude and longitude of the places at which they were taken; and are to be rendered to the war-office, for the purpose of having the calculations made concurrently by proper persons within the United States. Several copies of these, as well as of your other notes, should be made at leisure times, and put into the care of the most trust-worthy of your attendants to guard, by multiplying them against the accidental losses to which they will be exposed. A further guard would be, that one of these copies be on the cuticular membranes of the paper-birch, as less liable to injury from damp than common paper.
"The commerce which may be carried on with the people inhabiting the line you will pursue, renders a knowledge of those people important. You will therefore endeavour to make yourself acquainted, as far as a diligent pursuit of your journey shall admit, with the names of the nations and their numbers;
"The extent and limits of their possessions;
"Their relations with other tribes or nations;
"Their language, traditions, monuments;
"Their ordinary occupations in agriculture, fishing, hunting, war, arts, and the implements for these;
"Their food, clothing, and domestic accommodations;
"The diseases prevalent among them, and the remedies they use;
"Moral and physical circumstances which distinguish them from the tribes we know;
"Peculiarities in their laws, customs, and dispositions;
"And articles of commerce they may need or furnish, and to what extent.
"And, considering the interest which every nation has in extending and strengthening the authority of reason and justice among the people around them, it will be useful to acquire what knowledge you can of the state of morality, religion, and information among them; as it may better enable those who may endeavour to civilize and instruct them, to adapt their measures to the existing notions and practices of those on whom they are to operate.
"Other objects worthy of notice will be--
"The soil and face of the country, its growth and vegetable productions, especially those not of the United States;
"The animals of the country generally, and especially those not known in the United States;
"The remains and accounts of any which may be deemed rare or extinct;
"The mineral productions of every kind, but more particularly metals, lime-stone, pit-coal, and saltpetre; salines and mineral waters, noting the temperature