We have occasionally observed that the laws which regulate the weather, are precisely like those which regulate the flow of hot water in a boiler, and there is no more reason why we may not know all about one as the other, if we can get at the facts in detail, as we can the facts in a boiler which we use for hot water heating. We know that the current is not caused by the water made light by the heat under the boiler, but because there is a heavier pressure from the colder mass which flows into the boiler, and forces that which has been made lighter out of the way. It is a simple act of gravitation. That which is heaviest goes to the bottom, and the lightest is pushed up to the top. A stone sinks because it is heavier than water; a stick swims because the water is heavier than the stick. Atmospheric currents are caused in the same way. The sun lightens the tropical atmosphere, and the heavier northern rushes in to displace it. The sun warms the tropical waters, and the cold Arctic current rushes in to force it out of the way, and we have a gulf stream flowing north to fill in the chasm formed by the southward flow of the Arctic water.

How wonderful are the purposes of nature ! We look on the Arctic icefields and deprecate the dreary and awful waste; but without these ice fields we should not have rain or snow or healthful breezes. If we could but study the position of these moving masses of ice, there is no reason why we may not predict the general climate for months ahead. It is just this sort of knowledge Arctic research might bring us. No one cares now about the northern passage, but it is of vast meteorological importance to know that the sea can flow either to the right or to the left as it presses down on what we may now call the shores of the great Island which forms the North American Continent. We have yet an immense number of these facts to gain, but when gained meteorology will become an exact science.

Every one who has looked at this matter in this light, welcomes every arctic expedition. When last summer we learned from one of these expeditions that the immense ice sheet was much further westwardly than ever before, it was known that we might expect a very late spring here, and a correspondingly early one on the other side of the gulf stream. Just how it is every one knows. Here before us is a paper from the Isle of Wight, England, dated April 22nd, and they talk about peas in bloom, potatoes "hoed up for the last time," and "will be ready for market by the first of June." Here in Philadelphia, some eight hundred miles south of the Isle of Wight, we have potatoes scarcely out of the ground, and peas scarcely large enough to stick - not even the Hawthorn in blossom on this 24th day of May - and all because this immense mass of ice has pressed more heavily than usual against the north-eastern shores of our continent.

The time will come when we shall have weather stations connected by telegraph in these arctic regions; and blockhouses, well provisioned, stretching out from one to another like a chain of forts, and the great arctic problem will be solved, and, there can be no doubt, to the immense profit of all mankind.