ABOUT THE DIFFICULTY AND POSSIBILITY OF DETERMINING THE WEATHER.

Having now explained the rules referring to the conditions of our weather, and proved that owing to the geographical position of our country, to determine the weather in advance, is difficult, we wish to examine this difficulty a little more closely in pointing out the wrong direction which has hitherto been pursued in the science of meteorology.

The main difficulty in predicting the weather for any given place consists in this, that a change in the atmosphere need not originate in the place where it occurs. Thus, to-morrow's weather in New York is not a consequence of the condition of the air as it exists there to-day; for the air is continually moving, and, owing to many disturbances, is carried over city and country. We have no sure means of ascertaining whence the wind will come to us to-morrow. All we know is, that from all sides currents of air are moving simultaneously; from the north pole a cold current, from the equator a warm one, from the ocean one saturated with moisture. All these winds are in continual commotion, and have the characteristics of the neighborhood from which they come. If from the state of the weather in New York to-day it were desired to predict the weather there for to morrow, one ought to be able to overlook a space of about a thousand miles around; in other words, it must first be ascertained what is the state of the atmosphere within about a thousand miles of the city. Besides, there should be known the direction of all the winds within this wide space, and their speed, and whether they contain much moisture or little. Not without this information could a calculation be made about the velocity with which a change of the weather would take place in New York; what results the meeting of two or more currents of air might call forth; and what kind of weather this might produce there.

Weather, therefore, for the present state of meteorology, is but a subject of investigation into the existing condition of existing phenomena, and not a subject of prediction of coming phenomena. It is true, there are general rules by which a proximate success in predicting may be obtained. If winter begins mild, or, better, if southwest winds and rain prevail till the middle of January, it is very likely that this will be counterbalanced by a northeast wind in the latter part of the winter. The saying, therefore, is correct, "green Christmas and white Easter;" but this rule is by no means infallible, the counteraction may be accelerated by violent storms, or greatly retarded by mild currents of air.

Not before the time that meteorological stations are established throughout the land, and connected by electric telegraphs—a project which to us may seem immense, but to our children will appear very simple and natural—not before that time will a city like New York, for example, receive timely information about the conditions of the currents of air at all the stations. At each of these places the force of the current, its warmth, moisture, and weight will be accurately ascertained by instruments. Then, and then only, we may calculate what currents will meet and where, and what effects the meeting will have. If this be done on Saturday, the Sunday papers will be enabled to state precisely whether the church-goers must provide themselves with umbrellas or parasols.

But not for Sunday alone will this be of importance. It will be long after their establishment, that such weather-stations, connected by telegraphs, will prove their real efficiency and blessing; and our descendants, perhaps, will wonder how we could live without an institution, which to them will appear as simple and natural as do to us gaslights and railroads, which by our forefathers would have been rejected as idle dreams or works of witchcraft.