This afternoon First Sergeant Gerber took a party of men, the writer being one, and went some few miles up the river, to get a flat-boat which one of the guides informed us was hidden there. We found the boat, and as it grew dark launched it, commencing a passage down the rapid current of the Platte. We had not gone far, however, before the vessel upset, and the whole cargo of rifles and men was subjected to a cold bath. After some trouble in righting the boat the passage was resumed, two or three rifles and several hats making up all the losses that were sustained. But the members of the party also suffered considerable loss of blood during the trip, drawn by mosquitoes--they were so very troublesome that we had to wear handkerchiefs over our faces and gloves on our hands, and these were but a partial protection against their assaults. _July 5_ (Monday). We commenced operations this morning by hauling our boat out of the water and repairing and caulking it, and covering it with canvas. We christened the vessel _The Sapper_, and I painted the name on the side. We launched the boat, towed it to the crossing and rigged up a rope ferry. All being ready we carried over two wagons, loaded with timbers, which are to start to-morrow morning, together with a party of men, to build a bridge over a creek. _July 6_ (Tuesday). We began early to ferry over the train, and by noon had most of the wagons across. The party was sent a few miles ahead to build the bridge, and having completed that service returned to camp at night. We, for our part, carried over the last load about 5 o'clock, and then pitched camp. _July 7_ (Wednesday). At reveille the Company was detailed into parties; one party as pioneers, equipped with axes, and another as pontoniers, to be left here to take down the ferry and then follow after the Company.