Throughout the whole excursion the attention of the gentlemen of the expedition was constantly occupied upon the several subjects of investigation which were deemed essential to a topographical and scientific description of the country. In the discharge of our duties, however, we laboured under many disadvantages for want of a sufficient variety of instruments to furnish all the data proper and desirable in giving an account of the geology and meteorology of the country. A barometer would have been particularly useful; but out of three belonging to the expedition two were rendered completely unfit for use, partly by accident and partly by defects in their construction, and the third was in such a condition that it was not deemed advisable to take it with us, as it was not likely to remain fit for service but for a short time only. In ascertaining the humidity of the atmosphere a hygrometer would have been particularly useful, but it has never been in my power to procure one that had any claim to being accurate. In taking the various observations, however, that could be effected by means of the few instruments we had with us, no pains were spared, and no opportunities lost; those in particular, for the calculation of latitude and longitude, were taken as often as it was thought necessary, and with the utmost care and precision that circumstances would permit. On our arrival at Cape Girardeau we had contemplated to embark on board of the Western Engineer, which was at that port ready for our accommodation, {197} and sail for Louisville; but, learning that the water of the Ohio was at that time too low to admit even the passage of a boat drawing no more than fifteen or sixteen inches of water, we were compelled to seek another mode of conveyance. Those of the expedition who had been on duty during the two last seasons, being very anxious to visit their homes, arrangements were accordingly made for their return to Philadelphia, when they would be enabled to complete and report the intelligence they had collected. Messrs. Say, Peale, Seymour, and Lieut. Graham, being desirous to return by water, waited the opportunity of taking a passage to New Orleans, and thence to Philadelphia. Most of the curiosities collected by the expedition were placed in the charge of Mr. Say, to be shipped for this place. Lieut. Swift was left in command of the steam-boat and crew, with instructions to proceed with them to Louisville as soon as the water would permit. He was instructed to leave the boat in the care of the pilot employed on board of her,--order her crew of United States' soldiers to Newport, Kentucky, for winter quarters and subsistence, and report in person at Philadelphia, for topographical duty. GENERAL DESCRIPTION OF THE COUNTRY TRAVERSED BY THE EXPLORING EXPEDITION