History of submarines few years before the US, and paralleled subsequent US development in this area. In the 1950s, nuclear power partially replaced diesel-electric propulsion. The sailing of the first nuclear-powered submarine, the USN ""Nautilus"" in 1955 was soon followed by similar British, French and Russian boats. Equipment was also developed to extract oxygen from sea water. These two innovations, together with inertial navigation systems, gave submarines the ability to remain submerged for weeks or months, and enabled previously impossible voyages such as the crossing of the North Pole beneath the Arctic ice cap by the USS "Nautilus" in 1958. Most of the
Road to the North Pole mirror asking his reflection, in the form of a crazed clown, how he is doing. Brian and Stewie decide to go to the North Pole to kill Santa, but Brian does not want Stewie to get disappointed if Santa is not what everybody thinks he is; to this Stewie responds that Brian is as negative as Eeyore from Winnie-the-Pooh. To prevent Stewie from going to the North Pole he tells him that Santa is not real; Stewie questions this, also asking if Elmo, SpongeBob SquarePants and Curious George aren't real. On their way to the North Pole, Brian and Stewie