Box 18, Folder 7: Meteorology - Weather Bureau

Government Telegrams and Reports For The Benefit of Commerce

P. 9 p. 18

Dup. [1870?]

Government Telegrams and Reports For The Benefit of Commerce.

Popular attention is at this time directed to the formal undertaking, for the first time on this continent, under Government auspices, of an organized system of weather reports to be made by telegraph, with the purpose of giving information in advance of the approach and force of storms, for the benefit of commerce on the northern lakes and sea-board. The advantages to be gained, if success can be had, are so vast, and popular curiosity in reference to the subject is so general, that a brief statement of what has been undertaken in this regard in other countries, and of the steps which have led to the present action in our own, is thought worthy of publication.

The special characteristic of modern efforts, in the development of meteorological science, consists in co-operation among observers laboring in different fields, and thus securing the data for determining the simultaneous condition of the atmosphere over extended regions of country.

It is only by this means that the laws which govern the occurrence, motion, direction, and propagation of atmospheric disturbances can be ascertained. As soon as this truth was recognized and acted upon, the important fact was developed that storms moved in certain fixed directions, and at such rates of speed as permitted telegraphic notice of their approach to be given to places lying in their paths.

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The practicability of utilizing this knowledge for the benefit of the commercial interest became at once apparent, and resulted in the organization of systems of storm warnings in several of the European countries most interested in maritime affairs.

To the late Admiral Fitzroy, of the British Navy, belongs the honor of having been the first to put in operation a practical system of weather forecasts and storm signals, based on deductions made from numerous observations received by telegraph daily at a central point.

The first cautionary or storm-warning signals were made in England in February, 1861, and in August of the same year published forecasts of the weather were tried with such success, that by the spring of 1862 sufficient experience had been gained to justify the adoption of the system still in use.

The following description of the mode of collecting, collating, and distributing the requisite information, is condensed from the Weather Book of Admiral Fitzroy.

Twenty-two reports from as many different stations in Great Britain are received at the central office in London each morning, (except Sundays,) and ten each afternoon, besides five from the continent.

The morning reports are received at 10 o'clock, and are immediately translated from the conventional characters used for telegraphic transmission into the proper figures, which are reduced or corrected for scale errors, elevation, and temperature, and then written into prepared forms and copied several times. The first copy is passed to the chief of the department or his assistant, with all the telegrams, to be studied for the day's forecasts, which are carefully written on the first paper, and then copied quickly for distribution. At 11 o'clock reports are sent out to the Times, (second edition,)

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Lloyd's, and the Shipping Gazette, to the Board of Trade, the Admiralty, and the Horse Guards.

Soon afterwards similar reports are sent to the afternoon papers, and late in the day copies, more or less modified in consequence of telegrams received in the afternoon, are sent out for the early morning papers of the next day. The forecasts of weather add nothing ot the expense of the system, while their practical usefulness is becoming more and more apparent. They do not claim to be predictions or prophecies of the weather, but such an opinon as can be derived from scientific combinations and calculations, liable to be occasionally marred by some unexpected elemental action not yet provided against.

For convenience of publication, the forecasts are drawn up for the following arrangement of districts:

1. Scotland; 2. Ireland, around the coasts; 3. West central, (Severn to the Solway,) coastwise; 4. Southwestern England, from the Severn to Southampton, by the coast; 5. Southeastern England, (Wight to the Thames;) 6. East coast, (Thames to the Tweed.)

A broad general average is kept in view, referring to a day or more in advance, and to a district, rather than to one time or place only. Showers at particular places, or merely local squalls, are disregarded.

In some instances forecasts are made for two days in advance, and with fair success.

The following data are given in these telegraphic reports, viz: Height of barometer; height of thermometer; difference of wet-bulb thermomrter; true direction of wind; force of wind; condition of the sky; amount and time of rain or snow; sea disturbance.

These are represented by a system of numbers,

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which are transmitted instead of the words, thus materially reducing the bulk of matter to be sent, and without impairing the accuracy of the observations. Along the sea-coast, at points threatened by a storm, a system of signals is employed to notify all interested persons of the impending danger, its nature, and the probable direction from which it would come.

The day signals consist of a staff and two canvas shapes, one cylindrical, and the other conical in form. The cylinder or drum used alone indicates that stormy winds might be expected from more than one quarter.

The cone, with point upward, indicates that a gale is probable from the northward; with its point down, the cone indicates that a gale is probable from the southward.

The cone and drum together give warning of dangerous winds; the probable first direction being shown by the position of the cone—pointing up for northerly and down for southerly winds and the intermediate points.

Night signals are made by hoisting lanterns in position to correspond with those of the cone and drum in the day-time. Great caution is exercised in using the signals to inspire confidence in these warnings among seafaring men.

The value of the forecasts given is shown in a statement made by General Sabine to the Board of Trade. He says that he had examined the warnings given during the two years ending 31st of March, 1865, and found that in the first year fifty per cent. and in the second year seventythree per cent. were right. Warnings of storms were sent by Admiral Fitzroy to the north and west coasts of France, and from comparison with the records for the two winters of 1864—65 and 1865—66 it appears that of one hundred warnings sent dur-