From the present position of the lunar nodes and apogee, the vortices of our earth do not ascend into very high latitudes. Now, according to the principles laid down, the frequency of storms tends to lower the temperature in the warm regions of the earth, and to elevate it in the polar regions. Let us suppose the northern limit of the vortices to be in latitude 70°. There will be, in this case, a greater prevalence of northerly winds _within_ this circle of latitude, to supply the drain to the southward, and the back currents by passing above will descend at the pole, partaking of the temperature due to that elevation. The character of the arctic seasons may therefore be considered as partly dependent on the average direction of the wind. Suppose again, the extreme limits of the vortices to be about latitude 80°, the relative areas of the two circles are as 4 to 1; so that in this last case the exclusive range of the northerly winds is limited to one-fourth of the first area. South of 80° the wind will frequently come from the south, and by mixing with the local atmosphere of that latitude, will tend to ameliorate the small area to the northward. And the greater atmospheric commotion when confined to such a small circle of latitude, must assist materially to break up the polar ice; which would tend still more to equalize the temperature. By referring to our table, we see that the mean conjunction of the pole of the lunar orbit and the moon's apogee, was in longitude 128° on April 10, 1846, and let it be remembered that when the conjunction takes place due south or in longitude 270°, the vortices attain their greatest latitude north. When, on the contrary, the conjunction takes place due north or in longitude 90°,[48] the northern limits of the vortices are then in the lowest latitude possible. Sir John Franklin sailed in May 1845, and was certainly at the entrance of Wellington sound, near latitude 75°, April 3d, 1846, as the dates on the graves testify. That season, according to the theory, was a cold one; for the vortices could not reach so far to the northward in that year, and consequently there were no storms, properly speaking. It would probably be late in the summer of 1846, before the expedition was liberated, and as the prevailing winds would be from the northward, he would have little choice, but to stand to the westward if the state of the ice permitted. In his instructions he was to use every effort to penetrate to the southward and westward of Cape Walker, and he probably conformed to them under the circumstances, and passed the winter in the ice, in that neighborhood. And in 1847 we do not anticipate, from the theory, that he would make much progress westward.