Magnitude. Magnitude cannot be explained by definition. As Dr. Lardner observes, there is no magnitude so great, that we cannot conceive a greater, and none so small, that we cannot conceive a smaller. The diameter of the earth measures about 8,000 miles; but it is very small compared to the diameter of the sun, which measures nearly 900,000 miles: and this, again, is itself very small compared with the distance between the earth and sun, which measures little less than 100,000,000 miles; and even this last space, great as it is, vanishes to nothing, compared with the distance between the sun and the fixed stars.