for any intelligent observer to handle, weigh and test every quality of the air, it became evident that wind and storm, even the terrible cyclone, were not irresponsible forces, carrying health or death to and fro where they listed, but the result of plain, immutable; laws.  It was an American in this our Quaker City who reduced the wind to a commonplace effect of a most ordinary cause.  Franklin, one winter’s day passing with a lighted candle out of a warm room into a cold one, saw that as he held it above his head the flame was blown outward before him:  when he held it near the floor, the flame was blown into the room.  The shrewd observer stood in the doorway, instead of hurrying out, as most of us would have done, to save the wasting candle.  The warm air in the heated room, he conjectured, was expanded by the heat, consequently it rose as high as it could, and made a way for itself out of the room at the upper part of the doorway, while the heavier cold air from without rushed in below to fill the vacated space.  What if he took the equatorial regions or great tracts of arid desert for the heated room?  The air over them, subjected by the heat to constant rarefaction, must rise, must overflow above, and must force the colder air from the surrounding regions in below.  Two sheets of air will thus set in vertically on both sides, rise, and again separate above.  Here was an explanation of the great, steady, uninterrupted aerial currents which, at the rate of from fifteen to eighteen miles per hour, sweep the surface of the Atlantic and Pacific oceans.  The candle, no doubt, was wasted, but the secret of the trade-winds was discovered.

The idea was correct as far as it went.  It did not go very far, it is true.  It had not taken into account the earth’s rotation, whose force, according to Herschel, “gives at least one-half of their average momentum to all the winds which occur over the whole world;” nor the infinite variation in the movements of the atmosphere which we call winds, caused by the change in the sun’s motion, by the differing amounts of vapor held in them, by the physical configuration of the earth below, by the vicinity of the sea or arid deserts, and by the passage of storms or electric currents.

The science of meteorology, especially as regards wind, is as yet searching for general principles, which can only be deduced from countless facts.  We do not now, like Saint Paul, talk of the wind Euroclydon as of a special agent of God, but describe it by stating that it is an aerial ascending current over the Mediterranean, produced by the heated sands of Africa and Arabia.  We can even measure its heat at 200 deg.  Fahrenheit, and its velocity at fifty-four miles per hour.  But it attacks us just as unexpectedly as it did the apostle, and brings disease and death to Naples or Palermo to-day just as surely as it did to Cambyses.  The popular verdict on the matter would no doubt be that when meteorologists can not only describe the