Immediately upon admission to the corps, each sergeant is sent to Fort Whipple, in Virginia, opposite Washington, where he is taught the duties of his profession, which are “chiefly those pertaining to the observation, record and proper publication and report, at such times as may be required, of the state of the barometer, thermometer, hygrometer, and rain-gauge, or other instruments, and the report by telegraph or signal, at such times as indicated, and to such places as may be designated by the chief signal officer, of the observations as made, or such other information as may be required.” The text-books used in the school at Fort Whipple, are Loomis’s “Text Book of Meteorology,” Buchan’s “Hand Book of Meteorology,” Pape’s “Practical Telegraphy,” and the “Manual of Signals for the United States Army.” Instruction in the use of the instruments is also given, and the sergeant is taught to operate the telegraph. He is required to make daily recitations, and when he is considered prepared, by his instructor, he is ordered before an examining board, and is subjected to a rigid examination. If he is found properly qualified, he is assigned to a signal station in some part of the country, and is allowed an enlisted man to assist him in his duties.
There are eighty-five signal stations, located in various parts of the Union, from the Atlantic to the Pacific, and from British America to the Gulf of Mexico. Each of these is supplied with a full set of the instruments necessary for ascertaining the condition of the weather, etc., and is in charge of an observer-sergeant, who is required to make observations three times a day, by means of his instruments, which are adjusted to a standard at Washington. These observations are made at 8 A. M., at 4 P. M., and at midnight. Each post of observation is furnished with a clock which is regulated by the standard of Washington time, so that the observations are taken precisely at the same moment all over the United States.
The result of each observation is immediately telegraphed to the Signal Office at Washington, the Government having made arrangements with the telegraph companies to secure the instant transmission of these messages. The reports are limited to a fixed number of words, and the time of their transmission to a fixed number of seconds.
The signal stations, as at present located throughout the country, have been chosen or located at points from which reports of observations will be most useful as indicating the general barometric pressure, or the approach and force of storms, and from which storm warnings, as the atmospheric indications arise, may be forwarded, with greatest dispatch, to imperilled ports.
The work of the observers at the stations is simple. It is limited to a reading of their instruments at stated times, the transmission to Washington of the results of these observations, and of information of any meteorological facts existing at the station, when their tri-daily report is telegraphed to Washington. The work of the officers on duty at the Signal Office in Washington, is of a higher character, and demands of them the highest skill and perfect accuracy. The reports from the various stations are read and recorded as they come in, and from them, the officer charged with this duty prepares a statement of the condition of the weather during the past twenty-four hours, and indicates the changes most likely to occur within the next twenty-four hours. These statements are prepared shortly after midnight, and are at once telegraphed to the various cities and important ports of the Union, in time for their publication in the newspapers the next morning.
Professor Maury, of the Signal Office, thus sums up the working of the service:
“Each observer at the station writes his report on manifold paper. One copy he preserves, another he gives to the telegraph-operator, who telegraphs the contents to Washington. The preserved copy is a voucher for the report actually sent by the observer; and, if the operator is careless, and makes a mistake, he cannot lay the blame on the observer, who has a copy of his report, which must be a fac-simile of the one he has handed to the operator. The preserved copy is afterward forwarded by the Observer-Sergeant to the office in Washington, where it is filed, and finally bound up in a volume for future reference.
“When all the reports from the various stations have been received, they are tabulated and handed to the officer, (Professor Abbe,) whose duty it is to write out the synopsis and deduce the ‘probabilities,’ which in a few minutes are to be telegraphed to the press all over the country. This is a work of thirty minutes. The bulletin of ‘probabilities,’ which at present is all that is undertaken, is made out thrice daily, in the forenoon, afternoon, and after the midnight reports have been received, inspected, and studied out by the accomplished gentleman and able meteorologist, who is at the head of this work. The ‘probabilities’ for the weather for the ensuing day, so soon as written out by the Professor, are immediately telegraphed to all newspapers in the country who are willing to publish them for the benefit of their readers.”
Copies of the telegrams of “Probabilities” are also instantly sent to all boards of trade, chambers of commerce, merchants’ exchanges, scientific societies, etc., and to conspicuous places, especially sea-ports, all over the country.
While the professor is preparing his bulletins from the reports just furnished him by telegraph, the sergeants are preparing maps which shall show, by arrows and numbers, exactly what was the meteorologic condition of the whole country when the last reports were sent in. These maps are printed in quantities, and give all the signal stations. A dozen copies are laid on the table with sheets of carbon paper between them, and arrow-stamps strike in them (by the manifold process) the direction of the window at each station. The other observations as to temperature, barometric pressure, etc., etc., are also in the same way put on them. These maps are displayed at various conspicuous points in Washington, e. g., at the War Department, Capitol, Observatory, Smithsonian Institute, and the office of the chief signal-officer. They serve also as perfect records of the weather for the day and hour indicated on them, and are bound up in a book for future use.