If the reader will examine the map on page 93, he will see that the distribution of the Drift accords with this theory. If we suppose the side of the earth shown in the left-hand figure was presented to the comet, we will see why the Drift is supposed to be confined to Europe, Africa, and parts of America; while the right-hand figure will show the half of the world that escaped. "The breadth of the tail of the great comet of 1811, at its widest part, was nearly fourteen million miles, the length one hundred and sixteen million miles, and that of the second comet of the same year, one hundred and forty million miles."[1] On page 95 is a representation of this monster. Imagine such a creature as that, with a head _fifty times as large as the moon_, and a tail one hundred and sixteen million miles long, rushing past this poor little earth of ours, with its diameter of only seven thousand nine hundred and twenty-five miles! The earth, seven thousand nine hundred and twenty-five miles wide, would simply make a bullet-hole through that tail, fourteen million miles broad, where it passed through it!--a mere eyelet-hole--a pin-hole--closed up at once by the constant movements which take place in the tail of the comet. And yet in that moment of contact the side of the earth facing the comet might be covered with hundreds of feet of _débris_. Or, on the other hand, the comet may, as described in some of the legends, have struck the earth, head on, amid-ships, and the shock may have changed the angle of inclination of the earth's axis, and thus have modified [1. Schellen, "Spectrum Analysis," p. 392.] {p. 95} permanently the climate of our globe; and to this cause we might look also for the great cracks and breaks in the earth's surface, which constitute the fiords of the sea-coast and the trap-extrusions of the continents; and here, too, ### THE GREAT COMET OF 1811. might be the cause of those mighty excavations, hundreds of feet deep, in which are now the Great Lakes of America, and from which, as we have seen, great cracks radiate out in all directions, like the fractures in a pane of glass where a stone has struck it. The cavities in which rest the Great Lakes have been attributed to the ice-sheet, but it is difficult to comprehend how an ice-sheet could dig out and root out a hole, as in the case of Lake Superior, _nine hundred feet deep!_ {p. 96} And, if it did this, why were not similar holes excavated wherever there were ice-sheets--to wit, all over the northern and southern portions of the globe? Why should a general cause produce only local results?