In navigating in an ice pack, the method of procedure would be to reduce the buoyancy of the vessel to, perhaps, a couple of tons, and then steam ahead, and it will be observed that the forward portion of the boat extends downward a considerable distance under the water, so that when the forward portion of the boat contacts with heavy ice the reserve buoyancy will not be sufficient to lift or push the ice out of the way, and the vessel will then be automatically pushed under the ice and run along in contact with the under surface of the ice. A toothed recording wheel would give the exact distance travelled, and, of course, the compass will give the direction. Progress could be made in perfect comfort and safety under the ice at a rate exceeding one hundred miles per day. The _Protector_ was fitted out in 1903 for experimental navigation under the ice with an inverted toboggan built up over the conning tower. This arrangement enabled her readily to navigate under ice fields, and she successfully navigated under an ice field in Narragansett Bay eight inches thick. Ice two feet in thickness is sufficient to close navigation to the most powerful of ordinary surface ships, and great power is required to crush or break a lane through it by the specially equipped ice-breakers now used in northern latitudes. While ice is a deterrent to surface navigation, it is actually an aid to under-water navigation, providing the submarine boat is specially equipped with guide wheels or "runners" on top of the hull to enable her to slide or wheel along under the ice. A design of the under-ice submarine illustrated was prepared by me a number of years ago to meet the desires of an associate of Captain Nansen, the Arctic explorer, for a vessel that could be navigated either on the surface or under the ice. I explained the principal features and possibilities of a vessel of this type for under-ice navigation before the faculty of Johns Hopkins University, in Baltimore, in 1898, and at one time I thought one of the prominent New York newspapers was going to finance the building of such a vessel for North Polar exploration work, but the submarine was then looked upon as too much of an experiment and nothing ever came of the negotiations. Some years afterward, in Christiania, Norway, I met and discussed the project with Captain Scott Hanson, R.N., who was associated with Nansen in his historical search for the North Pole, and he became quite enthusiastic over the possibilities of a submarine of this type for North Polar exploration.