the roots came. Nevertheless, the passage of the meteor, whose narrow path was marked by devastation, would create a great commotion in the air, and there would be high winds raging for several miles on either side of the "wind-road." But (§ 799) let US consider for a moment the effect of the diurnal rotation of the earth upon one of these revolving discs 1000 miles in diameter: its height would scarcely be two miles, and its thickness would not be as great, in proportion to its diameter, as half the thickness of this leaf is to the length of an inch. Now the difference in rate of the diurnal rotation between the northern and southern limbs of the disc would be sufficient, irrespective of any other power, to break it up. Suppose its southern limb to be in 20° N., its northern limb would be 1000 miles, say 17°, farther north, that is, in 37°. Diurnal rotation would carry to the east the air in the southern limb at the rate of 845 miles an hour; but when this same air comes round on the northern limb, diurnal rotation would carry it eastward at the rate only of 720 miles. Because the wind hauls in a particular way, it does not follow, as by diagram (§ 799) it has been shown, that it is blowing in a circle, or that the centre of the storm is at right angles to its line of direction.
807. Extra-tropical gales.—In the extra-tropical regions of each hemisphere furious gales of wind also occur. One of these, remarkable for its violent effects, was encountered on the 24th of December, 1853, about three hundred miles from Sandy Hook, latitude 39° north, longitude 70° west, by the "San Francisco," steam-ship. That ship was made a complete wreck in a few moments, and she was abandoned by the survivors, after incredible hardships, exertions, and sufferings. Some months after this disaster I received by the California mail the abstract log of the fine clipper ship "Eagle Wing" (Ebenezer H. Linnell), from Boston to San Francisco. She encountered the ill-fated steamer's gale, and thus describes it: "December 24th. Latitude 39° 15' north, longitude 62° 32' west. First part threatening weather; shortened sail; at 4 p.m. close-reefed the top-sails and furled the courses. At 8 p.m. took in fore and mizen top-sails; hove to under close-reefed main top-sail and spencer, the ship lying with her lee rail under water, nearly on her beam-ends. At 1 30 a.m. the fore and main top-gallant-masts went over the side, it blowing a perfect hurricane. At 8 a.m., moderated; a sea took away jib-boom and bowsprit cap. In my thirty-one
