Saint Paul Signal Service


The Lofty Office of Signal Observer Lyons Who Dictates St. Paul’s Weather.
How the Many Observations Are Taken on Which Old Probabilities Works.
A Few Instruments and a Head for Figures With Much Patience and Practice.
Qualifications of the Observer – He is Not Sergeant – Another Cold Wave Signal.

He has been interviewed oftener and by reporters from more papers, within the last two months, than about any other man in St. Paul.  He sits in his room on the top floor of the chamber of commerce building and when his clicker rattles he knows where the storms are blowing.  He stands in with the head of the weather bureau at Washington, and when the chief says blizzard, he runs up a flag on the flagstaff that surmounts the chamber and the whole city knows that in Montana or the Northwest Territory is the crest of a wave that washes the mercury down to the bulb, and the populace turns up its coat collars and is glad that there is no danger that the palace will thaw.  He is observer P. F. Lyons, chief of the signal service in St. Paul, one of the men that is always glad to see a newspaper man, and tell him just what he wants to know in the shortest time and space possible, and apparently with the understanding that he is doing it that the public may get the information it craves and not that the curiosity of the reporter alone is to be satisfied.  He is solid with the newspaper men.  It was in April, 1882, that he came to the St. Paul office, since which time he has had a watchful eye on the weather of the entire Northwest.

The signal office was established here in 1870, Nov. 1, and there are two others in the state – one at St. Vincent and one at Moorhead.  In the little room where Officer Lyons is to be found are to be seen a thermometer fixed on the window casing, a barometer, a couple of telegraph instruments, on a little shelf within a cylinder in a case, an instrument for recording the velocity of the wind, and in one corner of the room a long arrow that turns with the weather cock above, and on a sort of a dial points out the direction of the wind.  Six observations of the weather are taken each day, three of them local and three telegraphic.  The latter are the ones sent to Washington to give Gen. Hazen the groundwork for a ten-line guess on the weather for the “upper Mississippi valley and the Northwest” that appears each morning in the paper.  They are taken at 6 a. m., 2 and 9 p. m.  The local observations are taken from the thermometer, the barometer and the hygrometer, the first for the temperature and the latter for the probabilities as to fair or foul weather.  The direction and


are noted, the dew point determined, and if it is in summer or the river is not frozen over, the observer notes the level of the river.  The observations of the thermometer and barometer are such as any one can make, and such as probably have been made, by more people this winter and within the past few weeks particularly than ever before in St. Paul.

To determine the dew point two thermometers are used, on the bulk of one of which water is placed and allowed to evaporate.  Any one who remembers how chilly it is on coming out of the water after “going in swimming” will easily recognize the fact that water in drying brings a lower degree of temperature, and it is on this principle that the wet and dry thermometers are used.  The wet bulb is allowed to dry and the difference in the degrees registered by this and a dry thermometer is noted.  The government has made computations and tables showing the dew point – the point at which moisture will be precipitated from the air, as it is on a pitcher of ice water in a hot day – for differences of any number of degrees from a fraction of one upward, and when this difference is noted the dew point is known by reference to a table.  For instance, if a dry thermometer registers at 65° and a wet one at 57°, then in the table the figures opposite 8° the difference will be the dew point.  For 8° the dew point is 50° and this is put down on the records.

Saint Paul Signal Service Chief, P.F. Lyons, 1886
Saint Paul Signal Service Chief, P.F. Lyons, 1886

All observations of the thermometer and barometer must be corrected after they are taken, to give uniformity to the observations throughout the country.  To do this requires a considerable knowledge of


and until one is familiar with the operations, considerable time.  Of course, in the barometer the cold or heat affect the height to which the mercury will rise, so that on a cold morning the fact that the mercury is falling may indicate nothing as to the moisture of the atmosphere.  Consequently the reading must be on a basis of some particular degree of heat, and to give uniformity, all observations are corrected for a temperature of 32° by means of tables and a few computations.  Another circumstance outside the condition of the atmosphere that affects the height of the mercury is the height at which the thermometer is fixed, and to secure uniformity in this respect, sea level is taken as the basis at which all observations are made.  To make the corrections for elevation more tables are used and more computation.  Still a third is needed for the imperfection of the instruments for it is impossible to make a barometer absolutely perfect, and each instrument has to be compared with a standard and its imperfection allowed for on each observation.  The observations of the thermometer are corrected to bring them to sea level and for the imperfections of the instruments.  It would probably take one who had not had much experience in making the computations, and yet understood the principles on which they are made, an hour’s time and considerable paper and pencil, but Observer Lyons makes the computations and verifies them nearly all in his head with a reference to his tables in a little less than twenty minutes.

In sending the observations to Washington a cipher is used, chiefly as a matter of quickness and to save telegraphic tolls.  A book like the telegraphic codes used by merchants is in each office, containing a system of words for about all conceivable state of wind or weather.  For instance, if there is wind accompanied by a rainstorm, the book gives for this combination of the elements the simple word “half.”  If the sky is clear and there is no wind with a prospect for fair weather, the simple word “usual” or some other may be given.  By this cipher it is impossible to bulls and bears to tap the wires and get important information in advance of the regular bulletin, unless, of course, the bulls and bears have the code.


is confining, as his observations must be taken at regular hours each day, and each day in the year.  Mr. Lyons says that the title “sergeant” as applied to himself is not correct as he has no military title and his position in the government service is not in anyway such as to give him that title.  His title is “Observer,” and his telegrams from Gen. Hazen are directed to him under that address.  He is something of a veteran in the service, having served at the main office in Washington, then at Montgomery, Ala., afterwards at Nashville, Tenn., and Leavenworth, Kan.  All officers in his position are required to have sufficient knowledge of telegraphy to send twenty-five words per minute and receive fifteen, and in this branch of the work Observer Lyons is something of an expert.  He has an assistant in his office, G. N. Salisbury of Minneapolis, who helps in various ways to make the weather.

But a single flag is at present in use, as an indicator of the coming weather – a white one with black centre.  In view of the recent interest taken in the weather, Mr. Lyons made an effort to secure a cold wave signal that could be seen at night, consisting of a red light to be hung from the staff above his office.  Owing to some delay it did not arrive in season for the opening weeks of the carnival, but it is expected to be here in a few days.

The Saint Paul Daily Globe
Sunday Morning, February 14, 1886
Volume VIII, Number 45, Page 6

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