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Service on February 2, 1874, at the instance of Professor Joseph Henry of the Smithsonian Institution, the entire body of Smithsonian weather-observers in all parts of the United States. This volunteer civilian force continues to the present day to contribute its scientific labors in behalf of the Signal Service researches in the domain of continental meteorology and climatology. The volunteer observers thus cooperating with General Myer, with others who have embarked in the work since 1874, now number 240, and their observational data great ly enrich the records of the Signal Office. Many of them have acquired great exactness and experience in instrumental observation and noting and recording physical phenomena, so that their monthly reports to the Chief Signal Officer alone make a rich repository of American climatology. This voluntary corps is undergoing constant additions, and inducements are held out by the Service to competent civilians, especially in the sparsely settled and frontier districts, to join in its investigations.

Practical Uses of Weather-Reports. With this brief notice of the organization of the Service and its methods of weather-observing and weather-forecasting, we hasten to the practical applications of the work. In referring to the wide-spread interest in the weather-predictions of the past few years, a recent writer in the "Quarterly Review" observes, "Some basis of solid value to the public must exist to account for such a general popularity of the weather-service." The fact is, that the public are just beginning to see some of its more obvious utilities.

The tri-daily "Indications" are designed to give timely notice of the general weatherchanges to occur in the twenty-four hours following their issue. As they are telegraphed from the Washington office, and adapted to the convenience of the daily press, they are greatly condensed, to bring the cost of telegraphing within the restricted means of the Service; and yet they must be made sufficiently full to cover the whole country. These conditions are hindrances to their usefulness, and the brevity of the dispatches exposes them at times to popular misinterpretation. But, notwithstanding these drawbacks, the scope of their practical application to all classes of in lustry is large and continually increasing. When the first propositions of a weather bureau were advanced, the highest end thought attainable, by the most sanguine, was to give warnings of the great storms that ravage the seacoasts of the United States. This, however, is but a small part of the public interests it subserves. The number of persons who find that the reports and forecasts of the Service may be utilized for every-day life is constantly increasing. Signal observers are not unfrequently subpoenaed to bring the records of the weather into the courts, as legal evidence in cases upon which they bear. Grain and cotton merchants ind the "Indications" of value in calculations

of the forthcoming crops. Emigrants and "prospectors" intending change of residence use them to determine the climate of new towns. Physicians, sanitarians, and boards of health employ their data to detect dangerous conditions of the atmosphere of the cities, and for investigating the origin and spread of diseases and epidemics, as in the case of the recent yellow-fever visitations of the South. The pork-packers, fruit-importers, and fish- and oyster-dealers keep an eye on them to secure themselves against exposure of perishable goods to weather too damp or too warin. They are of use to specialists in manufacturing and hygienic interests, and are consulted by thousands planning journeys or excursions for health or pleasure. River-boatmen, fariners, sugar-planters, fruit-growers, and ice dealers find occasion to utilize them. Mechanics judge from the prognostics whether they can work outside on the morrow. The meteorological data supply engineers with information indispensable for planning economical and storm-proof architecture. Railroad officials, during snow-blockades, are kept advised by the reports, so that they are enabled to make provision for clearing the tracks; and railroad freight-officers find them useful for facilitating transportation. These are some of the daily applications made of the Signal Service work in the interior and central, not less than in the seaboard sections of the country. In every branch of agriculture and trade the deductions that could be made from the published synopses and indications of the weather would have immensely enhanced value if the public could be instructed how to frame them. In military operations over the vast West, the intelligence of approaching storms is of no little value, in timing movements so as to avoid heavy roads and dangerous delays. "Had we, a quarter of a century ago," says a British meteorologist, "known the rigor of the Crimean climate, who would have dared to send out an army unprepared to meet the hardships of a Black Sea winter? Ask the physician at what price he would value the power of giving timely warning of a 'cold snap' to his patients. Ask the builders of London what they have lost in the last ten years by sudden frosts or unexpected downpours of rain. Above all things, go to the farmer and ask what he would freely pay to know at seed-time what weather he might really expect in harvest. The fact is, there is not a profession, not a handicraft, not a process in animal or vegetable life, which is not influenced by meteorological changes."

Wide Diffusion of the Weather-Reports.— The distribution of the tri-daily "Synopses and Indications" over the whole country may be understood from the following official facts: The total number of these forecasts - 1,095 issued every year-are telegraphed at the moment of issue to the principal cities, and are published in some form in almost every newspaper in the country. In many public and

conspicuous places, they are also bulletined for popular inspection. In order that they may reach the farming populations, an arrangement is effected with the Post Office Department, by which special "Farmers' Bulletins" may be distributed at an early morning hour of each day, except Sunday, along the railroads radiating from the chief cities of the Union. These "Farmers' Bulletins" contain all the matter of the "midnight" report made up in the Washington office at 1 A. M. of each day, which, when it reaches the outlying stations by telegraph, is printed before daylight, and copies of it mailed to the rural postmasters for many miles around, and by them displayed in their offices. There are now nineteen cities at which the Signal Service observers reprint and circulate the telegraphic forecasts to 6,042 sub-centers among the agricultural communities while the reports are yet fresh and timely. Each postmaster has the order of the Postmaster-General to display the report as soon as received in a frame furnished for the purpose, and to report in writing to the Chief Signal Officer the time of its receipt and display. The intelligence of weather-changes, with predictions and other data useful to the farmer in securing his crops or in other ways, it has been found, on an average, reaches the different railway stations, hamlets, and villages throughout the United States in the forenoon. As the predictions cover twenty-four hours, and often hold good for twice that period, they therefore reach the denser rural populations twelve or fourteen hours before the period to which they apply expires, and not unfrequently a day and a half or more.

To make the reports still more widely useful to the agricultural interests, the Chief Signal Officer, by an arrangement between the War Department and different railways, has established a "Railway Weather Bulletin Service." In this work 103 railway companies, distributing daily 3,180 reports to as many railway stations, are now without charge cooperating. The midnight report, exhibiting the "Synopsis and Indications," is telegraphed to the railway companies, whose superintendents are charged with seeing that copies of it are bulletined and posted along their lines a few hours after it emanates from the Washington office. By this means large masses of the rural populations, and residents of districts which can not otherwise be reached in time, secure the benefits of the Government weather service. This system of distribution is in its incipiency, but is capable of indefinite extension, and of diffusing the desired weather-data to vast numbers of farmers in the interior centers. The immense demand which has ever existed among all classes for weather-forecasts is strikingly illustrated by the fact, mentioned by the "Penny Post" (an old English paper) in 1833, that up to that year the annual sale of "Moore's Almanack," the weather prognostics of which were proverbially without any basis of scien

tific observations, still amounted to "a quarter of a million copies."

As many farmers, however, reside too far from an railway station or post-office to obtain timely reports of storms and weatherchanges, General Myer has for some time been preparing for distribution at cost-price among such a simple apparatus, which will serve even the uneducated as an indicator of coming changes. This is the "WEATHER-CASE, or FARMER'S WEATHER-INDICATOR." This automatically working instrument is of value in enabling agriculturists to interpret whatever official weather-intelligence reaches them, and to determine for themselves in advance the chief weather-changes, as well as to direct their thoughts and study to those atmospheric phenomena upon a knowledge of which their craft must so much depend. Instructions and rules for interpreting the instrumental variations will accompany the weather-case, and thus practically extend the already immense circle within which the reports are utilized.

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Preparing the "Synopsis and Indications."— From reading in the morning newspapers the Synopsis and Indications" for the day, no one not initiated in the method of preparing them would suspect the magnitude of the work involved in their preparation. The study prerequisite for each of the tri-daily press reports issued includes the draughting of eight graphic charts exhibiting the multiform data furnished by the simultaneous reports telegraphed from all the stations. These charts are: (a.) A chart of barometric pressures, temperatures, and winds (wind-direction and velocity) at the different stations, with the amount of clouds and the kind and amount of precipitation at each station. The isobars (or lines connecting stations where the barometric pressure is the same) are then drawn for every tenth of an inch, as also are isothermal lines for every 10° of temperature; while wind-directions are marked by arrows and their hourly velocities by numbers. (b.) A chart of relative humidities at all stations, with the character and amount of the upper and lower clouds, which have been well called "Nature's weather-guides." On this are traced lines of equal relative humidity over the country, showing the territorial areas over which precipitation is likely to ensue upon the reduction of temperature, or where the clouds are likely to be dissipated by a rise of temperature. As isothermal lines are drawn on this chart, such deductions are facilitated. (c.) A chart of the various cloudconditions prevailing at the time over the United States, with the "weather" at each station depicted by symbols; also the minimum temperatures and the maximum wind-velocities. The cloud-areas-each form of cloud represented by a different symbol-are outlined, and each one is distinguished. The appearance of the western sky at each station as observed at sunset, which affords a strong indication of the weather to be anticipated for

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"run" of the weather in the separate sections of the vast field of observation over which it is executing its manifold manoeuvres. These charts have all to be draughted in about an hour or an hour and a half; but they are inter-corrective, each chart serving as a check on the others.

the next twenty-four hours, is also marked on this chart. (d.) A chart of the normal pressures-those which from a long series of observations should be expected-and of variations of the actual from the average pressures. The deviations or "departures" of the actual pressures from those which generally prevail are marked on the map by appropriate lines; as also, by the lines of "no variation," the districts in which the atmosphere is in a state of equilibrium are delineated. (e.) A chart of actual variations of pressure transpiring since the last report, showing the fluctuations of the atmosphere during the previous eight hours. (f) A chart of dew-point variations which have taken place at the stations during the preceding eight and twenty-four hours. (g.) Lastly, a chart of dew-points, vapor-tensions, and the actual amounts of humidity in the air at the various points of observation. All these charts, each covering the whole of the country, must be made out, and the mass of data they embody sifted and analyzed, preliminary to the preparation of every one of the tri-daily bulletins issued from the central office. This system of mapping, symbolizing, grouping, and numerically notating the data enables the Signal Officer to picture to his eye the exact status of the aërial masses, and to catch the PERCENTAGE OF VERIFICATIONS FOR EACH MONTH OF THE YEAR ENDING JUNE 80, 1879.

Armed with this charted material, the officer preparing the predictions proceeds first to make up the "Synopsis," showing the conditions of weather now existing, and then to deduce and write the "Indications," showing the changes to occur afterward. As soon as this is done, the deductions are telegraphed direct from the office of the Chief Signal Officer to all parts of the country, and are given to the newspapers. The average time elapsing between the simultaneous reading of the instruments at the 290 separate stations scattered over the United States, and the issue of the "Synopsis" and "Indications" based on these readings, has been calculated at one hour and forty minutes.

Verifications of Predictions.-An analysis of the predictions, made for the year ending June 30, 1879, and a comparison with the weather-conditions which actually occurred within the twenty-four hours next ensuing, give the following percentages of verifications:

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80.6 84.4 83.5 87.6 80.1 88.6 65.5 93.8 89-8 81.8 84.3 84.9
77.8 87.6 85.9 88.4 90.8 87.0 86.0 94.1 90.5 87.2 85.6 86.0
83.5 89.5 89.2 87.3 91.8 £5.5 88.6 92.8 91.6 82.0 80.4 79.8
89.8 91.9 83.4 87.2 88.2 90.1 87.0 92.7 90.7 85.5 76.6 80.4
89.7 91.2 89-5
89.1 90.4 88-6 83.5 90-9 87.8 81.9 76.7 81.1
84.9 86-7 81.9 85.3 91.0 87.1 87.0 94.1 91.2 88.2 84.7 88.6
83.1 67.6 83.8 87-4 89.7 88.4 88.1 92.5
81.6 82.8 85.8 86.8 92.4 85.5
84.3 86.8 84.2 89.4 92.4 85.2
82.9 83.2 62.8 86.8 91.5 84-6

89.6 81.8 87.1 86.8 86.8 95.8 89.4 84.4 84.2 84.9 85.6 92.1 88.1 81.5 84.1 88.8 84.6 91.4 89.1 80.1 84.0 81.2 98.0 89-7 82.9 82.8 88.7

Total percentage of verifications... 88.7 87.1 85.0 87.5 90-7❘ 87.1 86.2 Percentage of verifications for the year (changes of barometric pressures, temperatures, wind-direction, and character of weather expected. comprised)....

Percentage of verifications for the year (forecasts of the character of the weather only)....

These percentages of accuracy refer to predictions of barometric, thermometric, winddirection, and general weather changes, which are more difficult to make than those relating to future conditions of the weather alone. The percentage of accuracy of the forecasts of the weather alone (including the state of the skies, whether clear, fair, or cloudy, and whether with or without rain) in all of the different districts has been 90.7. The percentage for the Pacific coast region is 89.3. Out of a hundred preannouncements of the single element of the "weather" for all parts of the country (apart from barometric changes), ninety have been fulfilled by the event.

River Reports. The important work of overseeing the fluctuations and floods of the great Western rivers, so sensitive to the meteorological changes occurring in their basins,

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was at an early period of its history undertaken by the Signal Service. The interstate commerce being necessarily much affected by the oscillations of the rivers, timely warnings of their rise and fall, and daily reports of the exact depth of water at numerous points, were eagerly asked for. The observations of this kind were found of so much importance that they have been extended over the Western, Southern, and California rivers, and deductions made from them, indicating impending changes, are daily published in the Washington weatherreports. All measurements at each river-station are made from the "bench-mark," as known to the river-men of the vicinity, and the depth of water from the bed of the river to this mark is daily gauged and telegraphed to the central office. Knowing from such telegrams the height of the river at any station,

and knowing the present and antecedent rainfall higher up the river-valley, the office is thus enabled to calculate and announce the time and degree of coming changes. Thus timely premonitions of the great flood-waves that pass down the Mississippi, and also its fluctuations, are issued from the office to the places which it reached on its southerly way.

The gauge used is very simple. It is a plank (A, Fig. 2) of pine or oak timber, two inches thick, ten inches wide, and long enough, when placed obliquely on the slope of the riverbank, to cover the extreme low-water and high-water marks. When firmly imbedded in

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the earth, the mean level of the river or "bench mark" is marked on it as zero, and it is carefully graduated in feet and inches by means of an upright measuring-rod (B), a straight-edge and spirit-level crosswise, as shown by the dotted lines (C) in the cut, each foot and its subdivisions exactly corresponding to the vertical foot and subdivisions of which they are intended to be indices. A "danger-line" is marked on the gauge, showing how tar the water may rise, but no farther, without danger of a flood. The reports telegraphed to the press, stating how near each stream has risen to or fallen below the "danger-line," enable the public to predetermine dangerous inundations, and furnish steamboat-men and merchants the daily information requisite for intelligently directing the movements of their craft. During the flood-months the tele

graphic river-reports are especially valuable to all river-shipping, and to all interested in the traveling and transportation facilities which depend upon it, as well as giving timely warnings of ice floods or sudden rises and falls. The levee systems of the Mississippi and other great rivers can thus be guarded, and the immense agricultural interests secured, as the flood-warning comes in time to summon the State force to strengthen the imperiled works. Daily bulletins of the river-reports are regularly displayed at Augusta (Ga.), Cairo, Chattanooga, Cincinnati, Davenport, Dubuque, and Keokuk (Iowa), La Crosse (Wis.), Leavenworth, Louisville, Memphis, Morgantown (W. Va.), Nashville, New Orleans, Omaha, Pittsburgh, Portland (Oregon), Red Bluff (Cal.), Shreveport, St. Louis, St. Paul, Umatilla (Oregon), Vicksburg, and Yankton (D. T.).

In connection with this service, surface and bottom water-temperatures at points upon the rivers, lakes, and seacoasts are observed and reported for the United States Commissioner of Fish and Fisheries, with a view to ascertain the proper waters in which to plant the various food-fishes and furnish statistics desired for the development of the national system of piscicul

ture.

There is also to be mentioned the oversight given by the office to the changes of temperature by which the canals are closed by freezing, or opened by thaws for transportation. During the months when the market-rates and freightschedules are affected by the probabilities of the canals closing, and when these waterways are thronged with hundreds of laden barges, the daily predictions indicate the thermometric conditions likely to ensue along their lines of transit. Such information may often protect the public from the imposition of excessive railway-rates in the shipment of the graincrops, especially in any autumn season of protracted mildness, and effect a large saving to the mercantile world.

The Cautionary Storm-Signals, which accompany the "Synopsis and Indications" issued to the press three times each day, constitute a very important part of the Signal Service work; and it was the possibility of preparing such storm-warnings for the benefit of navigation that originally gave the chief stimulus to the establishment of a Weather Bureau. The United States has a double front with over 7,000 miles of sea-beaten coast, exclusive of the shore-line of its great lakes, ravaged by terrific tempests; and this vast stretch of marginal territory needs to be environed with stations from which observations can be taken, and premonitory intelligence of cyclone and anticyclone signaled by day and by night to storm-menaced shipping. If no other duty devolved upon the Service, this alone would more than justify its whole cost, and warrant its extension. It is one of the most difficult and responsible tasks which can fall to the meteorologist, to put his science to its utmost

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