The temperature of the ocean depths cannot permanently remain lower than that of the coldest parts of the surface. Temporarily this might indeed happen when a solar change first reduced the storminess and strengthened the westerlies and the surface currents. Gradually, however, the persistent deep-sea circulation would bring up the colder water in low latitudes and carry downward the water of medium temperature at the coldest part of the surface. Thus in time the whole body of the ocean would become warm. The heat which at present is carried away from the earth's surface in storms would slowly accumulate in the oceans. As the process went on, all parts of the ocean's surface would become warmer, for equatorial latitudes would be less and less cooled by cold water from below, while the water blown from low latitudes to high would be correspondingly warmer. The warming of the ocean would come to an end only with the attainment of a state of equilibrium in which the loss of heat by radiation and evaporation from the ocean's surface equaled the loss which under other circumstances would arise from the rise of warm air in cyclonic storms. When once the oceans were warmed, they would form an extremely strong conservative force tending to preserve an equable climate in all latitudes and at all seasons. According to the solar cyclonic hypothesis such conditions ought to have prevailed throughout most of geological time. Only after a strong and prolonged solar disturbance with its consequent storminess would conditions like those of today be expected. In this connection another possibility may be mentioned. It is commonly assumed that the earth's axis is held steadily in one direction by the fact that the rotating earth is a great gyroscope. Having been tilted to a certain position, perhaps by some extraneous force, the axis is supposed to maintain that position until some other force intervenes. Cordeiro,[67] however, maintains that this is true only of an absolutely rigid gyroscope. He believes that it is mathematically demonstrable that if an elastic gyroscope be gradually tilted by some extraneous force, and if that force then ceases to act, the gyroscope as a whole will oscillate back and forth. The earth appears to be slightly elastic. Cordeiro therefore applies his formulae to it, on the following assumptions: (1) That the original position of the axis was nearly vertical to the plane of the ecliptic in which the earth revolves around the sun; (2) that at certain times the inclination has been even greater than now; and (3) that the position of the axis with reference to the earth has not changed to any great extent, that is, the earth's poles have remained essentially stationary with reference to the earth, although the whole earth has been gyroscopically tilted back and forth repeatedly.