Detroit, Tuesday noon.--I improve the first moment I could secure for the purpose to continue my letter, hoping to fill the sheet in time for the next mail. On Monday (yesterday) morning I went botanizing, but found absolutely nothing. I kept near the shore of the lake that I might see the first steamboat that came in sight, and one was momently expected. It did not arrive, however, until eleven o’clock, and it was a little after noon before we were under way. The wind was very fresh, and the billows of Lake Erie would not have disgraced the Atlantic. It was, however, in our favor, and we made good progress; but for about two hours we had to run in the trough of the sea, so that the boat pitched and rolled sadly. At sunset we arrived at Sandusky in Ohio. The entrance to the bay is very beautiful. The lake is studded with islands of various sizes, all covered with trees, with here and there a house or a cultivated field upon the larger ones. It was dark before we left; the water was still rough. I went into the cabin and read until it was time to occupy my berth. I am not sure whether I told you that I had lost Bishop Berkeley. I left it behind at Avon, where I was too sick to think about it, but the driver promised me faithfully, for value received, to look it up and send it to the stage-office at Buffalo, where I may find it on my return. I was roused this morning just at daybreak. We were just at Detroit. I established myself at a hotel, got my breakfast, and sallied forth to survey the town, which is larger than I supposed and most beautifully situated. As soon as I thought your friend, C. W. Whipple,[34] might be at his office I called to pay my respects and deliver the doctor’s letter. He was not in; but arrived in a few minutes. He is a good-looking man, but I suspect rather older and a good deal fatter than when you knew him. His black hair has a few silver threads mingled with it, but his countenance is youthful and most thoroughly good-natured. We had some conversation; then went to see Dr. Pitcher, but he was not at home: thence to Dr. Houghton’s house, which is entirely occupied as a store-house for the stuff collected in the State survey. It is astonishing what a prodigious quantity of labor Dr. H. and his companions have done and what extensive collections they have made. Dr. H. is not now at home but is expected to-morrow. We went next to the State-House, but did not find Governor Mason at his office. We looked through the building, at their commencement for a State library, etc., where we met some of the dignitaries of the State. We ascended into the cupola which crowns the building, where we have a most beautiful view of the town and region round about, the roads all diverging from the centre, the noble river, which we could trace from its commencement in Lake St. Clair. The people are evidently very proud of the prospect. By the way, I hear that the doctor’s protégé Dr. Fischer has been here, and