The outstanding feature of such vessels as the Fram and the Roosevelt was their rigidity. Their construction followed the general principle of the onion, consisting of numerous layers of heavy oak sheathing shored up from the inside with a veritable cob-web of balks, stanchions and braces. In addition to this, the sides of these ships were shaped so as to offer as small a vulnerable target as possible. The idea was that the stupendous pinch and pressure of the ice-pack failing to get a firm hold of the vessel should project her up from and out of the ice. This idea is graphically illustrated by an ordinary, household orange seed pinched sharply between the thumb and forefinger. But I could not help smiling at the naive short-sightedness of these earlier men, for, assuming as sometimes happened, that the constructive features functioned as outlined, what then? The ship was merely lifted up until she canted over at a ridiculous and uncomfortable angle where she lay on the ice, a helpless and absurd spectacle. Further motion in any direction was plainly impossible except at the whim of the floe itself which often evinces a contradictory tendency to move southward instead of northward as per schedule. While not wishing to discard entirely the idea of elusive conformation I saw at once that radical innovations would be necessary in order to accomplish my object. In a word, I proposed to convert the Kawa into a non-rigid type of vessel. "Triplett," I said, during our first conference, "what is the slipperiest animal you know?" The ancient mariner scratched his head reflectively before replying. "Seals." "Right!" I cried. "Go to the seal, thou sluggard! Triplett, it's an idea! We'll make the Kawa as easy to handle as a greased hot water bottle." For many days we worked over the plans and eventually began actual operations on the Kawa herself, hauling her out for the purpose at Tutbury's shipyard. She was completely eviscerated. Her oak ribs and keel were removed and replaced by Austrian bent-wood, of the finest temper. A thin layer of yew-planking was laid over her sides with lapped, sliding joints, filled with elastic roofing-cement. Outside of this came a second layer of slippery elm (3/8" × 2-1/2") laid diagonally so that the joints crossed those of the yew. The entire hull was then covered with seal-skin, fur side out. When she slid from the ways on her re-launching the Kawa took the water as noiselessly as a musk-rat, and it was with the greatest difficulty that we made her fast as she slipped from the ship-wright's grasp at the slightest pressure.[3] "Gosh-t-a'mighty," grinned Triplett. "She's a seal!"