Morning journal and courier., 1891-12-08
ALL ABOUT THE WEATHER.

the Weather for the Last I05 Years-How the Efficiency of the | Government weather Bureau is Being Increased-The New Haven l Daily Weather Map. OF AGRICULTURE, WEATHER BUREAU. NEW HAVEN, CONN.,, Dec. 5, 1891. It is desired to keep the public fully in formed concerning the efforts which are being made to extend the work of the weather bureau in order that the publica- tions and warnings may secure 8 wider and be more generally under stood. The following explanation of the work of the department, with full de- scription of the weather maps, has been prepared especially for the COURIER. It will very useful information and pre- served by many for reference:
 The daily weather map will continue to be posted in prominent places in this city and in the towns throughout the state; charts, showing the lowest temperatures, and on which cold waves are wildly DOT trayed, will be prepared each day and, although not for distribution, can be inspected by anyone calling at this office. The records of the weather bureau increase in value every year, as the period covered becomes longer; many stations have now been established twenty years, and on the 10th instant this office will have been established nineteen years. The longer the period covered, ob- viously the more important are the rec ords, as better opportunity is furnished perature data New Haven is especially for tunate, in that in addition to the weather bureau, record of temperature (morning, afternoon, night, maximum and min1mum), for the period of eighty-six years prior to 1865 has been prepared and published by the Connecticut Academy of Arts and Sciences. This record of 105 years is not equalled by any other city with the single exception of New York. There is at pres ent break of eight years Q866- 1873. but it is hoped to secure an acceptable record for. that period in order to have complete data.
 Specially prepared charts showing for the entire country temperature by de- cades, the distribution of precipitation, the average, earliest and latest dates of frosts, the average eloudiness, etc., etc., are now available to any persons who de- sire to consult them.
 During the coming year special efforts will be made to further extend the work of this bureau in the direction of agricul- ture. The forecasts, in addition to being published in the daily newspapers, will be posted in the railroad stations throughout the state, weather and temperature flags will be displayed at an increased number of towns, and frost warnings will be sent to any places requesting them. In the case of early frosts these warnings are in valuable to the tobacco growers, the planter may protect his crops by a covering of any kind; the radiation of heat from the ground may be checked and the plants saved by building fires on the outskirts of the fields, and thereby producing an artificial covering of smoke, which has the same effect as cloud. The heat which is ra- diated from the ground goes no higher than the smoke, and is there reflected back to the earth, so that very little heat is lost, and frost is prevented.
 A critical study of the relations existing between the growth of crops and the tenn perature, humidity, precipitation, sun- shine, etc., will be made under the super vision of the agricultural experiment stations. It is expected that, as result of this study, valuable information may be secured which may eventually be used by the farmers.
 The daily weather map which was re- ferred to above is the most important publication issued by the weather bureau to the public and, as the number who use it is increasing every day, the following explanation may not be out of place: The New Haven map is issued at about Il a. m. every day; on it are chartered the l weather conditions prevailing at selected stations as observed at @. m, seventy temperature, wind velocity and amount oi precipitation in the past twenty-four hours are entered in the order named. The direction of the wind is shown by l an arrow, which ''fies with the wind , being different in this respect from the wind-vane, which points to the direction from which the wind comes. The state ot l the weather is shown by lines drawn in circle which is immediately over the sta l ton. As soon as the charting of these data is completed, the isobars Zines con | nectlng places or embracing sections o1 equal air pressure) are drawn for eacl tenth of an inch; isotherms (dotted line connecting places having the same degree of temperature) are drawn for each ter | degrees; the section or sections of coun try having the highest and lowest air pres sure are marked respectfully "high" anG l Glow"
 The area covered by high pressure o air usually has clear and cool or colt weather, whereas the reverse is the case il advance of and surrounding an area of loy pressure (storm center, where rain or snos and cloudiness, with comparatively higl temperature, prevail. The drift of the at mosphere being from west to east, tn charting of these cyclonic and anti-cycloni areas by isobars is necessary to show at
 glance their respective centers and the di rection in which they are moving, graph l T. 4
 several unbroken lines and by the arrow showing the direction of the wind, tn air flowing into the tlow," with spira inward motion, contrary to the move ments of the hands of watch, and out o "high" with the hands of watch. l
 will be evident to the intelligent student
 after little study, that the nearer tn isobars are to one another and the greate
 the difference in pressure, the more rapi
 will be the flow of air from the greater t
 the lesser pressure, just as bali will rol
 with much greater rapidity down stee
 inclined plane than on 8 moderate in
 clination. In all severe storms ther
 is marked difference in pres
 the Glow" Cold waves, weather an
 temperature changes, and the probabilit
 of thunderstorms are easily located b
 studying the map. The several laws o
 storms will gradually unveil themselve
 to the mind of the student of the may
 That severe local storms occur in tn
 southeast quadrant of low pressure area
 that the wind blows spirally toward
 'low" or storm center, blowing from tn
 northeast when the storm moves up tn
 coast, shifting to north and northwest
 with clearing weather, as the flow" move
 beyond this vicinity to the eastward; als
 in the case of storm over tn
 lakes the wind in this vicin
 ity blows from the east or south
 east, shifting to south, southwest, yves
 and northwest as the storm moves dow,
 the St. Lawrence valley; that the tenn
 perature rises in advance of storm, an
 falls after it has passed; that storms gen
 orally move in the direction of greates
 rainfall, or snowfall, or where the air i most humid, are all facts evolved from
 study of the weather map. A synopsi of the weather changes in the past twenty 1 four hours and local forecast for thirty
 six hours based upon local condions ant
 the data referred to above, are also en
 tered on the map. --- -v. .
 H. J. Cox, Observer. A MINUTES SESSION.
 The Senate Meets and at once Ad