On account of the severe cold and deep snow little progress had been made by White’s men in building boats; but with the arrival of the superintendent and more laborers the work went ahead rapidly under the direction of Jonathan Devol, a ship builder. The largest boat was a galley constructed of heavy timber to deflect bullets and covered with a deck-roof high enough for a man to walk upright under the beams. It was 50 feet long and 13 feet wide with an estimated carrying capacity of 21 tons, although, as Putnam records it, it was of green timber and its real capacity, therefore, uncertain. The _Adventure Galley_ is the name commonly ascribed to this boat, although as an afterthought some called it the _American Mayflower_. Rufus Putnam in his diary written at the time calls it “Union Galley.” Since one boat would not transport the 48 men with their horses, tools, baggage, and food to support them until their crops matured, a large flatboat, 28’ x 8’, and three canoes were also constructed. It will be interesting to know something of what these “canoes” were like. They were not the hollowed-out log Indian canoes, nor were they of birch bark. Putnam describes them as of two tons, one ton, and 800 pounds burthen, respectively. The popular small boat of the Ohio River, large enough to carry more than would the log canoe, was called a pirogue. It was a log canoe split in half lengthwise and with a wide flat section inserted between the two halves. This made a substantial and safer boat, with greatly increased carrying capacity, yet easy to handle, and, of course, easy for the pioneers to build with the primitive materials at hand. And, speaking of boats and pioneers, Cutler records in his diary that on August 15, 1788, Tupper, who had been among the original party of settlers, took him down the river to see his new “mode for propelling a boat instead of oars.” This consisted of a “machine in the form of a screw with short blades, and placed in the stern of a boat, which we turned with a crank. It succeeded to admiration, and I think it a very useful discovery.” Thus, in the wilderness of Northwest Territory and 50 years before it came into general use, the screw propeller was invented and successfully demonstrated.