Dear Sir,――In the last number of the Museum, you say that in England, February has nearly the same character as our March, and is regarded as the opening of spring. Will you please tell me, in the next number, why England or London should have an earlier spring than New York――being ten degrees north of New York?――and oblige your subscriber, WILLIAM. _Answer._ In reply to the preceding inquiry, we must first remark, that the curious fact mentioned by William, has been variously explained. Our theory upon the subject is this. Greenland, a vast island at the northern point of our continent, is a mighty ice-house, perhaps as extensive as the whole United States. Here the ice and snow are piled up from century to century, imparting to all the regions around something of its own chilly atmosphere. The northerly winds that come even to us have something of old Greenland’s breath in them. For this reason, as we think, all the northern portions of North America are much colder than they would otherwise be. If our correspondent, William, will look at a map of the eastern continent, he will see that the Arctic Ocean occupies the whole space to the north of about seventy-two degrees of latitude. There is no Greenland there――no great mass of land to hoard up the ice and snow from age to age, and furnish an everlasting ice-house to scatter abroad its freezing influences. To the north of the eastern continent, there is ever an open, unfrozen sea, tending rather to abate than increase the cold. These simple facts will show one great reason why our continent should be colder than the eastern continent, and will serve in part to answer William’s inquiry. There are other curious facts in relation to this subject, which have their bearing upon the question, but we have hardly time to state them now. We will only add, that the western coast of the American continent has a much milder climate than the eastern. At Astoria, which is in latitude about forty-seven degrees, it is as mild as at Philadelphia, which is at about forty degrees. The same is the fact in relation to the eastern continent; at the southern point of Kamschatka, which is about the latitude of London, it is almost as cold and tempestuous as at Greenland. Various causes have been assigned for these remarkable facts, but we cannot notice them now. ――――