If we were accurate chroniclers, we should have to go back to Aristotle and the Chaldeans to show the origin and purpose of these little offices, just as Carlyle has to unearth Ulfila the Moesogoth to explain a word he uses to his butter-man. The world is so new, after all, and things so inextricably tangled up in it! In this case, as it is the sun and wind and rain which are the connecting links, it is easy enough to bring past ages close to us. The Chaldeans, building their great embankments or raiding upon Job's herds, are no longer a myth to us when we remember that they were wet by the rain and anxious about the weather and their crops, just as we are; in fact, they felt such matters so keenly, and were so little able to cope with these unknown forces, that they made gods of them, and then, beyond prayers and sacrifices, troubled themselves no further about the matter. Even the shrewd, observant Hebrews, living out of doors, a race of shepherds and herdsmen, never looked for any rational cause for wind or storm, but regarded them, if not as gods, as the messengers of God, subject to no rules. It was He who at His will covered the heavens with clouds, who prepared rain, who cast forth hoar-frost like ashes: the stormy wind fulfilled His word. Men searched into the construction of their own minds, busied themselves with subtle philosophies, with arts and sciences, conquered the principles of Form and Color, and made not wholly unsuccessful efforts to solve the mystery of the sun and stars; but it was not until 340 B.C. that any notice was taken of the every-day matters of wind and heat and rain.
Aristotle, the Gradgrind of philosophers, first noted down the known facts on this subject in his work On Meteors. His theories and deductions were necessarily erroneous, but he struck the foundation of all science, the collection of known facts. Theophrastus, one of his pupils, made a compilation of prognostics concerning rain, wind and storm, and there investigation ceased for ages. For nearly two thousand years the citizens of the world rose every morning to rejoice in fair weather or be wet by showers, to see their crops destroyed by frost or their ships by winds, and never made a single attempt to discover any scientific reason or rules in the matter—apparently did not suspect that there was any cause or effect behind these daily occurrences. They accounted for wind or rain as our grandfathers did for a sudden death, by the "visitation of God." In fact, Nature—which is the expression of Law most inexorable and minute—was the very last place where mankind looked to find law at all.
About two hundred and thirty years ago Torricelli discovered that the atmosphere, the space surrounding the earth, which seemed more intangible than a dream, had weight and substance, and invented the barometer, the tiny tube and drop of mercury by which it could be seized and held and weighed as accurately as a pound of lead. As soon as this invisible air was proved to be matter, the whole force of scientific inquiry was directed toward it. The thermometer, by which its heat or cold could be measured—the hygrometer, which weighed, literally by a hair, its moisture or dryness—were the results of the research of comparatively a few years. Somewhat later came the curious instrument which measures its velocity. As soon as it was thus made practicable 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 aërial 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 aërial ascending current over the Mediterranean, produced by the heated sands of Africa and Arabia. We can even measure its heat at 200° 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 sirocco, but give warning of its coming, their science will justify its claim to consideration. The common sense of mankind always demands as a royalty from every science daily practical benefits to the mass of men and women. It is not enough for meteorologists to have proved that the atmosphere varies in weight, in temperature or velocity of motion according to fixed rules, or to be able to explain why no rain falls on a certain portion of the coast of Portugal, while a like coast-exposure in England is incessantly drenched; or to have determined beyond a doubt that precisely as the ocean of water, under the influence of the moon and wind, ebbs and flows and has its succession of storms or calms, the ocean of air in which we are enveloped answers to the influence of the sun in great tidal movements, and has also its vast steadily moving waves of cold or heat or moisture. These discoveries of general truths must be brought to bear directly on men's daily life before they will have fulfilled their true purpose. It would seem as if nothing were more easy than to bring them so to bear. Meteorology, more intimately perhaps than any other science, concerns our ordinary affairs. The health of mankind, navigation, agriculture, commerce, the hourly business and needs of every man, from the merchant sending out his cargo and the consumptive waiting for death in the east wind, to the laundress hanging out the family wash, are ruled by that most mysterious, most uncurbed of powers, the weather. We may rub along through life with scanty knowledge of the history of dead nations or the philosophy of living ones, but heat and cold, the climate of the coming winter, yesterday's rainfall or to-morrow's frost, are matters which take hold of every one of us and affect us every hour of the day. Now, to bring the known general truths of this science to practical rules, or to base upon them predictions of storms or changes in the weather during any future period, requires, as Sir John Herschel stated twelve years ago, "patient, incessant and laborious observations, carried on in every region of the globe." One reason why this is required is the perpetually shifting conditions of heat, wind and storm. A man who sat down to work a mathematical problem in the days of Job, if there was such a man, found its result just the same as the school-boy does to-day: figures not only never lie, but never alter. But the man who solves an equation of which the winds and waters are members finds that the sum to be added varies with every hour. There are, so far as is yet known, no regularly recurring cycles of weather on which to base predictions: the conditions of heat and wind and moisture are never precisely the same at any given point. Hence the necessity, if we would give the science stability and bring it to bear on our daily life, of educated, skilled observers at different points to collect and report simultaneously the daily details of the present conditions.
It is this daily detail of fact which the United States government supplies through the little stations of observation one of which we have stumbled into on the Jersey beach. Americans, indeed, have from the first taken hold of this science with a most characteristic effort to reduce it to practical uses, to bring it at once to bear on the well-being at least of farmers and navigators. Dove had no sooner published his chart of isothermal lines and charts, showing the temperature throughout the world of each month, and also of abnormal temperatures, than our government issued the Army Meteorological Register for the United States, which for accuracy and fullness had never been equaled. In these the temperature and rainfall for each month of the year were shown. The forecasts of the weather now published daily in this country, and which come so directly home to every man's business that Old Probabilities is a real personage to us all, have been given in England for several years under the supervision of Admiral Fitzroy.
But it is high time now that we should come back to our little wooden house on the beach, and tell what we know of its occupants and uses. The courteous gentleman (in a blue flannel suit for "roughing it") who sits at the telegraphic wires is Sergeant G——, belonging to the Signal Service Department of the army. Instruction in this department is given at Fort Whipple, Va. One hundred officers besides Sergeant G—— are now in charge of stations, with 139 privates as assistants. The average force at Fort Whipple is 140 men. These men are, in point of fact, soldiers liable to be called into active service in the field: their duty there, however, is not fighting, but signaling and telegraphy—a duty quite as dangerous as the bearing of arms. Fresh recruits for this service are divided into those capable of receiving instruction only in field duty and those for "full service," which includes, with military signaling and telegraphy, the taking of meteoric observations, the collating and publication of such observations, and the deduction from them of correct results. Passing two examinations successfully in the latter course, the signal-service soldier is detailed for duty at a post as assistant, and after six months' satisfactory service is returned to Fort Whipple for the special instruction given to observer-sergeants. When qualified for this work he is detailed, as a vacancy occurs, for actual service.
Having thus discovered how our friend the sergeant came into his post, we looked about to see what he had to do there. The brilliantly-colored flags overhead drew the eye first. These flags serve the purpose of an international language on the high seas, where no other language is practicable. Twenty thousand distinct messages can be sent by them. Rogers's system has been, adopted by the United States Navy, the Lighthouse Board, the United States Coast Survey and the principal lines of steamers. Each flag represents a number, and four flags can be hoisted at once on the staff. With the flags there is given a book containing the meaning of each number. Thus, a wrecked ship cries silently to the shore, "Send a lifeboat" by flags 3, 8, 9, or says that she is sinking by 6, 3, 2; or a vessel under full sail hails another by 8, 6, 0, or bids her "bon voyage" with 8, 9, 7. Owing to the difficulty of distinguishing colors in cloudy days or when the flags will not fly, other systems of signaling are used: that of cones similar to umbrellas being considered in the English service one of the most efficient, a different arrangement of cones on the staff representing the nine numerals. Men may convert themselves into cones in an emergency by raising or letting fall their arms, and two men thus give any signal necessary. As the flags, however, belong more especially to Sergeant G—— 's duty on the field of battle or to exceptional cases of storm and danger, we pass them by to examine into his daily round of duty. Outside, a queer little house of lattice-work perched on a headland shelters the thermometers and barometers: on a still higher point directly over the foaming breakers is the anemometer, the little instrument which measures the swiftness of the fiercest cyclone as easily as the lightest spring breeze. It consists of four brass cups shaped to catch the wind, and attached to the ends of two horizontal iron rods, which cross each other and are supported in the middle by a long pole on which they turn freely. The cups revolve with just one-third of the wind's velocity, and make five hundred revolutions whilst a mile of wind passes over them. A register of these revolutions is made by machinery similar to a gas-meter. The popular idea, by the way, of the speed of the wind runs very far beyond the truth: we are apt to say of a racer that he goes like the wind, when the fact is the horse of a good strain of blood leaves the laggard tempest far behind; the ordinary winds of every day travel only five miles an hour, a breeze of sixteen and a quarter miles an hour being strong enough to cause great discomfort in town or field: thirty-three miles is dangerous at sea, and sixty-five miles a violent hurricane, sweeping all before it.
Our friend the sergeant examines seven times a day at stated periods the condition of the atmosphere as to heat, weight and moisture, the velocity of the wind, the kind, amount and speed of the clouds, and measures the rainfall and the ocean swell: all these observations are recorded, and three are daily reported to headquarters at Washington. In these telegrams a cipher is used—as much, we presume, to ensure accuracy in the figures as for purposes of secresy. In this cipher the fickle winds are given the names of women with a covert sarcasm quite out of place in the respectable old weather-prophet whom every housewife consults before the day's work begins. Thus, when the telegraph operator receives the mysterious message, "Francisco Emily alone barge churning did frosty guarding hungry," how is he to know that it means "San Francisco Evening. Rep. Barom. 29.40, Ther. 61, Humidity 18 per cent., Velocity of wind 41 miles per hour, 840 pounds pressure, Cirro-stratus. N.W. 1/4 to 2/4, Cumulo-stratus East, Rainfall 2.80 inch."?
Besides these simultaneous reports from the one hundred and eight United States stations which are telegraphed to the central office at Washington, there are received there daily three hundred and eighty-three volunteer reports from every part of the country, these being the system of meteorological observations under control of the Smithsonian Institution for twenty-four years, and given in charge to the Signal Service Bureau in 1874. In addition to these, again, are simultaneous reports from Russia, Turkey, Austria, Belgium, Denmark, France, England, Algiers, Italy, the Netherlands, Norway, Spain, Portugal, Switzerland, Canada—in all two hundred and fourteen. When we add together, therefore, the