,,learn ,,one ,,thing ,,every ,,day ,,july #a #aiaf ,,serial ,,no4 #aaj ,,the ,,mentor ,,the ,,weather ,by ,c4 ,f4 ,,talman ,of ,the ,united ,states ,weather ,bureau ,,department ,,of ,,science #c4jj ,,per ,,year ,,fifteen ,,cents ,a ,,copy ,old ,probabilities ,shall tomorrow's weather be fair or foul8 ,blow wind--blow moistly from the ,south1 for ,i go afishing4 ,nay1 good friend1 exclaims the golfer1 the day must be dry and the wind in the west4 ,the farmer moistens his finger and points it toward the sky4 ,rain1 come1 quickly1 for my crops1 is his prayer4 ,but the maiden's voice is full of pleading3 ,let the sun shine tomorrow that my heart may be light on my wedding day4 99 99 99 99 99 ,and so1 through the days and seasons1 humanity with all its varied needs1 turns anxiously1 entreatingly to ,old ,probabilities4 ,and how is it possible for him to satisfy the conflicting demand8 ,he may1 on the same day1 please the farmer in the ,west1 the fisherman in the ,south1 the golfer in the northern hills1 and the bride in the eastern town4 ,but how can he suit them all in one locality on a single day8 ,old ,probabilities is willing and he loves humanity1 but his powers and privileges are limited4 ,there are those who say that it is due to the kind endeavors of ,old ,probabilities to satisfy everybody that our weather has at times become so strangely mixed4 99 99 99 99 99 ,old ,probabilities is a gentle family name and came out of the affection of the people4 ,the name was a matter of pleasantry4 ,it was given to the ,chief of the ,united ,states ,weather ,bureau when the department was first established by ,congress1 and its source lay in the phrase1 ,it is probable1 with which all the weather predictions began4 ,but ,old ,probabilities1 genial prophet and lover of his fellow men1 is passing away1 for the officer who organized the ,weather ,bureau became in time displeased with the name and changed the form of the daily prediction so as to read1 ,the indications are4 ,the phrase is formal and severe4 ,there is naught but cold comfort in it4 ,our hearts turn back fondly to ,old ,probabilities and his friendly assurance3 ,it is probable that tomorrow will be fair4 ,illustration3 ,chickamauga ,park1 ,tenn41 in an ,ice ,storm ,,the ,,weather ,by ,,charles ,,fitzhugh ,,talman ,librarian of the ,u4 ,s4 ,weather ,bureau ,,the ,,mentor 4 ,,department ,,of ,,science 4 ,,july #a1 #aiaf ,,mentor ,,gravures ,,central ,,office ,,of ,,the ,u4 ,s4 ,,weather ,,bureau1 ,,washington1 ,d4 ,c4 ,a ,,simple ,,weather ,,station ,a ,,majestic ,,cumulus ,,cloud ,,the ,,observatory ,,on ,,monte ,,rosa ,,launching ,a ,,meteorological ,,kite ,,the ,,effects ,,of ,,snow ,,and ,,ice--,,the ,,campus1 ,,princeton ,,university ,entered as second-class matter1 ,march #aj1 #aiac1 at the postoffice at ,new ,york1 ,n4 ,y41 under the act of ,march #c1 #ahgi4 ,copyright1 #aiaf1 by ,the ,mentor ,association1 ,inc4 ,it is easy to lay too much stress upon the unimportant aspects of weather4 ,it furnishes a bit of conversation over the teacups2 it accentuates the twinges of rheumatism2 it spoils a holiday4 ,all this1 however1 is mere byplay4 ,the real work of the weather--the work that explains the existence of costly weather bureaus1 such as the one upon which our ,government spends more than a million and a half dollars annually--is momentous beyond calculation4 ,consider such facts and figures as these3 ,the head of the ,british ,meteorological ,office recently declared that bad weather costs the farmers of the ,british ,isles about one hundred million dollars a year4 ,in our own country it has been estimated that a difference of one inch in the rainfall occurring during ,july in six ,states means a difference of two hundred and fifty million dollars in the value of the corn 7maize7 crop4 ,the world over1 the damage wrought by hail-storms is said to average about two hundred million dollars a year4 ,in the city of ,galveston a single hurricane once destroyed twenty million dollars' worth of property and six thousand human lives4 ,thus we might proceed indefinitely4 ,the fact is that man's welfare is conditioned to an enormous extent and in an endless variety of ways by the vicissitudes of the atmosphere2 hence the study of weather--meteorology--is one of the most important of sciences4 ,it is also one of the most strikingly neglected6 ,at the office of the ,weather ,bureau in ,washington there is a meteorological library of some thirty-five thousand volumes4 ,but meteorological libraries are rare2 meteorological books are scarce in other libraries2 and meteorologists are so uncommon that whoever declares himself one is likely to be asked1 ,what is a meteorologist8 ,illustration3 ,,stations ,,of ,,the ,,united ,,states ,,weather ,,bureau ,showing two extreme types3 one1 an office on the twenty-ninth floor of the ,whitehall ,building1 ,new ,york ,city1 with instruments installed on the roof2 the other1 an independent observatory building1 with free exposure on all sides1 at ,st4 ,joseph1 ,mo4 ,the meteors studied by the meteorologist are not shooting stars1 but the phenomena of the atmosphere1--rain and snow1 cloud and fog1 wind and sunshine1 and whatever else enters into the composition of weather and climate4 ,,the ,,atmosphere ,the ocean of air in which human beings live1 even as deep-sea fishes live at the bottom of the liquid ocean1 is called the atmosphere4 ,unlike the liquid ocean1 it diminishes rapidly in density from the bottom upward4 ,at an altitude of three and one-half miles it is only half as dense as at sea-level4 ,this is higher than the highest permanent habitations of man4 ,mountain-climbers and balloonists have attained greater altitudes2 but above a level of about five miles the air is too greatly rarefied to support life4 ,balloonists who ascend still higher must carry a supply of oxygen with them4 ,a little above the ten-mile level the air is only one-eighth as dense as at sea-level4 ,the atmosphere extends at least #cjj miles above the earth1 at which height its density is computed to be only one two-millionth as great as at sea-level4 ,the weather with which human beings are concerned may be said to extend upward seven or eight miles2 i4e41 to the level of the higher clouds4 ,the layer of the atmosphere lying between sea-level and the upper cloud level has certain characteristics that distinguish it from the air above it1 and is known as the troposphere4 ,the heating of the atmosphere by the sun is the beginning of all weather1 and the temperature of the air is the most important weather element4 ,as soon as we begin to study atmospheric temperature1 we encounter a paradox4 ,the heat of the air is all derived from the sun 7except a minute quantity from the interior of the earth1 and an infinitesimal quantity from other heavenly bodies71 and it would therefore seem at first glance that the upper layers of the atmosphere should be warmer than the lower4 ,experience proves the reverse to be the case4 ,a mountain overgrown with tropical vegetation on its lower slopes is1 if high enough1 crowned with eternal snows4 ,a thermometer carried upward in the air shows under average conditions a fall of temperature of one degree 7,fahrenheit7 for every #cjj feet of ascent4 ,this fall of temperature with ascent continues to the upper limit of the troposphere1 where the average temperature is something like #gj degrees below zero4 ,illustration3 ,,the ,,new ,,idea ,,in ,,weather ,,observatories ,the ,observatory of the ,ebro 7,spain71 founded by ,spanish ,jesuits1 is devoted to studying the interrelations of sun1 earth and air4 ,its admirable equipment includes apparatus for the direct and spectroscopic study of the sun1 for measuring solar radiation1 atmospheric electricity1 earth currents1 terrestrial magnetism1 and earthquakes2 besides the ordinary routine of a meteorological observatory4 ,the results of all these observations are published side by side1 to facilitate comparison4 ,above the troposphere is a region called the stratosphere1 or isothermal layer1 in which an ascending thermometer shows irregular and generally small changes of temperature--not infrequently a rise of temperature with ascent4 ,the exploration of the stratosphere is one of the most fascinating fields of meteorological research1 but lies somewhat beyond the scope of an essay on weather4 ,it is carried out chiefly with the aid of small free balloons1 some of which 7sounding balloons7 bear self-registering thermometers and other instruments1 while others 7pilot balloons7 bear no instruments1 but show by their movements the drift of the air currents4 ,the greatest altitude ever attained by a sounding-balloon was #ba4h miles2 by a pilot-balloon1 #bd4b miles4 ,the branch of meteorology dealing with the study of the upper air is called aerology4 ,illustration3 ,a ,,lonely ,,outpost ,,on ,,the ,,verge ,,of ,,the ,,antarctic ,the ,argentine meteorological station in the ,south ,orkneys4 ,once a year an expedition is sent from ,buenos ,aires to relieve the staff of four observers4 ,this is the southernmost permanently inhabited spot on the globe2 and it has not even wireless communication with the rest of the world4 ,reverting to the temperature of man's environment1 the reason why the atmosphere is warmest at the bottom is this3 ,the sun's rays come to us from outer space in the form of vibrations in the ether1 and warm the air to only a slight extent in passing through it4 ,they are absorbed by the ground1 and converted into heat waves4 ,the air is then warmed by contact with the warm ground4 ,lastly1 the warming of the lower air gives rise to air-currents1 which distribute the heat through the atmosphere4 ,,barometric ,,pressure ,if our weather were uniform1 it would furnish little matter for conversation2 in fact1 would hardly be weather at all4 ,changeableness is the salient feature of weather1 and to understand weather changes one must know something about barometric pressure4 ,like all other forms of matter1 the invisible air has weight4 ,at sea-level it exerts a downward pressure averaging #ad4g pounds to the square inch4 ,atmospheric pressure is measured by means of an instrument called the barometer1 in which the weight of the air is balanced against a column of mercury4 ,as the height of the mercurial column varies with the pressure of the air1 and is taken as the measure of the latter1 we follow the practice of expressing pressure 7a force7 in linear units 7inches or millimeters74 ,this practice is retained even in the use of the aneroid barometer1 which contains no mercurial column4 ,hence1 when we say that the average barometric pressure at sea-level is #bi4ib inches1 we are really expressing in a roundabout way the weight of the air at that level4 ,illustration3 ,,how ,,the ,,camera ,,analyzes ,,lightning ,the same flashes photographed with 7a7 a stationary camera1 and 7b7 a camera revolving on a vertical axis4 ,one of the flashes is seen to have consisted of several successive discharges along an identical path ,courtesy of ,u4 ,s4 ,bureau of ,standards and ,popular ,science ,monthly4 ,barometric pressure not only varies somewhat regularly with altitude--diminishing as we ascend--but also less regularly from place to place in a horizontal direction1 and from time to time at a given place4 ,in studying the weather meteorologists frequently wish to compare the barometric pressures prevailing at a certain time at a number of places lying in the same horizontal plane4 ,given a system of meteorological stations scattered over a certain territory1 the first step is to secure simultaneous readings of the barometers at these stations4 ,then1 if the stations are at various altitudes1 as they commonly are1 corrections must be applied to the readings to reduce all to a common plane2 the plane adopted for this purpose is sea-level4 ,since most stations are above sea-level1 and since atmospheric pressure diminishes with altitude1 reduction to sea-level generally involves applying an additive correction4 ,,the ,,weather ,,map ,now please attend carefully to what follows2 because ,i am going to attempt to put into a minimum number of words the essential facts concerning the weather map1 the best clue to weather mysteries yet devised by man4 ,at about #bjj stations of the ,weather ,bureau1 distributed over the ,united ,states1 the barometer and other meteorological instruments are read twice a day2 viz41 at #h ,a4 ,m4 and #h ,p4 ,m41 eastern standard time4 ,the readings are promptly telegraphed in cipher to ,washington1 where they are entered on a map4 ,the barometer readings at the different stations1 reduced to sea-level as just explained1 will vary1 say1 from #bi to #ca inches4 ,lines1 called isobars1 are now drawn through places having the same pressure2 the intervals between the lines corresponding to differences in pressure of one-tenth of an inch4 ,lines 7isotherms7 are also drawn to connect places having the same temperature1 a little arrow at each station shows the direction of the wind at that point1 and various other symbols are used to facilitate the interpretation of the map2 but the isobars are more important than anything else4 ,illustration3 ,,cirro-,,stratus ,the appearance of this cloud precedes by a day or so the arrival of rainy and stormy weather ,illustration3 ,,alto-,,cumulus ,illustration3 ,,fair ,,weather ,,cumulus ,this cloud marks the summit of an ascending air current1 and appears toward midday or early afternoon in the warm season4 ,when the air rises powerfully to great heights1 cumulus is built up in mountainous masses and may become cumulo-nimbus1 the thundercloud4 ,here is the weather map for the morning of ,january #i1 #ahhf4 ,the solid curved lines are isobars1 representing barometric pressures ranging all the way from #bh4g to #cj4h inches4 ,it will be seen at a glance that these lines tend to assume roughly circular forms1 inclosing regions where the pressure is lower or higher than the average4 ,moreover1 the little arrows 7which fly with the wind7 show that the winds round a center of low pressure tend to blow in a direction contrary to that followed by the hands of a clock 7in the southern hemisphere the reverse is true71 but instead of blowing in circles are inclined somewhat inward toward the center4 ,round a center of high pressure 7in the northern hemisphere7 the typical circulation of the winds is exactly opposite 7clockwise1 and inclined outward71 though the accompanying map does not show this particularly well4 ,illustration3 ,,weather ,,map ,,january #i1 #ahhf ,an area of low pressure1 with its system of winds1 is called a cyclone1 or low4 ,an area of high pressure1 with its system of winds1 is called an anticyclone1 or high4 ,note that a cyclone is not necessarily a storm1 though the one shown on this map1 with its center not far from ,new ,york ,city1 was a very violent storm1 which1 when this map was drawn1 was sweeping up the ,atlantic coast4 7,popular usage applies the term cyclone to the tornado47 ,the strength of the winds in a cyclone depends upon the contrast in barometric pressure between its center and its outer border4 ,a cyclone with crowded isobars always has strong winds2 when the isobars are widely spaced the winds are gentle4 ,illustration3 ,,ascent ,,of ,a ,,sounding ,,balloon ,the first made in the ,united ,states2 at ,st4 ,louis1 ,mo41 in #aijd ,these areas of low and high pressure1 in addition to their movements about their centers1 move bodily across the country1 in a general west-to-east direction1 at an average speed of over #ejj miles a day4 ,this double movement may be compared to that of a carriage-wheel1 rotating and advancing at the same time4 ,most of our cyclones enter the country from the ,canadian ,north-west--though many come from other regions--and nearly all of them pass off to sea in the neighborhood of the ,gulf of ,st4 ,lawrence4 ,their route across the country varies greatly1 depending in part upon the season4 ,illustration3 ,,the ,,kite ,,house ,,at ,,an ,,aerological ,,observatory ,some of the kites are much the worse for wear after flying in a storm ,,the ,,weather ,,in ,,cyclones ,,and ,,anticyclones ,barometric pressure is not an element of weather1 in the ordinary sense of the term1 since the fluctuations of pressure that occur in the human environment are entirely inappreciable to the senses4 ,we have seen1 however1 that pressure is intimately related to wind1 which is a weather element of much importance4 ,in noting that systems of high and low pressure are constantly traveling across the country1 and that they are accompanied by winds having fairly definite characteristics in relation to each1 we have taken an important step toward bringing order out of the 7to the uninitiated7 chaotic sequence of weather4 ,obviously1 a system of telegraphic weather reports makes it possible to keep close watch of these wind systems1 and1 from their locations on today's weather map1 to form some idea where they will be tomorrow4 ,thus the weather forecaster is enabled to give notice of the imminence of those violent winds that destroy life and property at sea1 and1 to a less extent1 on land4 ,there is an element of uncertainty in such predictions--since storms1 unlike railway trains1 are not confined to fixed routes and regular schedules--but the practised forecaster acquires an instinct that helps him to forestall their vagaries4 ,illustration3 ,,sending ,,up ,a ,,meteorological ,,balloon ,,on ,,lake ,,constance ,between ,switzerland and ,germany4 ,now what is true of wind is also true to a certain extent of the other elements of weather1--they bear typical relations to the distribution of atmospheric pressure4 ,cyclones are usually preceded by rising temperature and accompanied by cloudiness and rain or snow2 anticyclones are usually preceded by falling temperature and attended by fair weather4 ,referring again to the map of ,january #i1 #ahhf1 and following the course of the isotherms1 or temperature lines1 we see that abnormally cold weather prevailed over the ,middle ,western and ,southern ,states4 ,the isotherm of zero dips far south across northern ,texas1 ,arkansas1 ,mississippi1 ,alabama1 and ,tennessee2 while in the upper ,mississippi and ,missouri ,valleys the temperatures were from #bj to #dj degrees below zero4 ,these regions were1 in fact1 in the grip of a severe cold wave1 which had entered the country a day or two before1 preceding the anticyclone here seen central north of ,dakota4 ,cold northwesterly winds were sweeping over the ,great ,plains1 and as far south as the ,gulf4 ,illustration3 ,,hoarfrost ,minute crystals of ice deposited from the air4 ,under a magnifying-glass they show a variety of beautiful forms ,the same map shows typical weather accompanying the cyclone central on the ,atlantic coast4 ,from the seaboard west to the ,mississippi ,valley rain or snow had fallen within the previous twenty-four hours 7indicated by shading71 and snow 7indicated by ,s7 was falling at the moment of observation at a majority of stations within this area4 ,elsewhere in the same region the weather was cloudy4 ,the foregoing remarks indicate in a general way the significance of the weather map and the principles upon which scientific weather predictions are based4 ,the endless procession of highs and lows brings to any place on the map constant alternations of heat and cold1 storm and sunshine4 ,the forecaster watches the procession1 and draws his inferences as to what will happen in this or that part of the country within the next day or two 7forty-eight hours is about the limit of his outlook74 ,long-range forecasting is still a thing of the remote future4 ,forecasts for a week in advance1 are1 indeed made by the ,weather ,bureau with the aid of reports from a chain of stations extending round the globe1 but these are in very general terms4 ,illustration3 ,,marvin ,,rain ,,and ,,snow ,,gage ,with trumpet-shaped wind-shield at top4 ,in the middle is seen the cylindrical collector4 ,this is removed and weighed with its contents to ascertain the amount of rain or snow that has fallen ,in ,january1 #aiad1 the ,bureau began publishing a daily weather map of the ,northern ,hemisphere4 ,this publication is1 at present1 suspended on account of the war4 ,,some ,,weather ,,miscellanies ,it would require a book1 rather than a brief essay1 to describe all the vicissitudes of weather1 and many books that attempt to do this have been written4,a ,we have space here only to mention a few important features of the weather met with in our own country4 ,a ,see ,brief ,list of ,meteorological ,textbooks and ,reference ,books1 #c;d ed41 by ,c4 ,fitzhugh ,talman4 ,for sale by the ,superintendent of ,documents1 ,washington1 ,d4 ,c4 ,price #e cents4 ,the southern and southeastern part of a cyclone1 some hundreds of miles from the center1 is a favorite breeding-ground for thunderstorms and tornadoes4 ,thunderstorms of the type known as heat thunderstorms also occur with no special relation to cyclonic centers in regions where the ground has been intensely heated4 ,in either case the storm is built up by rapidly ascending air1 which cools and condenses its water vapor1 first into enormous clouds 7cumulo-nimbus1 or thunderheads71 and then into rain1 frequently accompanied by hail4 ,it would be necessary to go to some length to explain the familiar electrical manifestations of the thunderstorm--some points1 indeed1 are not perfectly clear to meteorologists--but it should be stated that these are always the result1 not the cause1 of the storm4 ,lightning is an electrical discharge between cloud and earth1 or cloud and cloud1 and thunder is simply the violent soundwave set up by the sudden expansion of the heated air along the path of the discharge1--the same acoustic phenomenon that accompanies an ordinary explosion4 ,illustration3 ,,the ,,effects ,,of ,,an ,,ice ,,storm ,,at ,,canton1 ,n4 ,y4 ,march #be-bg1 #aiac ,illustration3 ,,summit ,,hotel ,,at ,,summit1 ,,cal4 ,on ,march #ah1 #aiaa4 ,a three-story building whose first story is buried under twenty-six feet of snow ,a tornado 7popularly miscalled a cyclone7 is an extremely violent vortex in the air1 usually less than #a1jjj feet in diameter4 ,besides its very rapid rotary motion1 it has a progressive motion at a speed averaging forty or fifty miles an hour4 ,its position at any moment is marked by a black funnel-shaped cloud1 which grows downward from the sky and does not at all times reach the earth4 ,a waterspout at sea is an identical phenomenon1 though usually less violent4 ,along its narrow path the tornado demolishes everything1--wooden houses are blown to splinters1 trees uprooted or stripped of their branches1 structures of heavy masonry laid in ruins4 ,something like a hundred lives are lost each year in these storms1 on an average1 and one of them 7,st4 ,louis1 ,may #bg1 #ahif7 destroyed thirteen million dollars' worth of property4 ,illustration3 ,courtesy of the ,scientific ,american ,a ,,waterspout ,,near ,,beaufort1 ,n4 ,c41 ,,in ,,august1 #aiaa ,illustration3 ,,turpain',s ,,thunderstorm ,,recorder ,or ceraunograph4 ,this is one of several instruments designed to register the natural electric waves1 or strays1 which sometimes interfere seriously with the transmission of wireless telegrams4 ,strays are often generated by lightning discharges1 near or distant1 and this instrument therefore serves to give notice of an approaching thunderstorm ,a blizzard is a high1 cold wind1 accompanied by blinding snow1 which in winter sometimes blows out of the front of an advancing anticyclone1 especially in our ,north-,central ,states4 ,a similar wind1 with or without snow1 is called in ,texas a norther4 ,a chinook is a warm1 dry wind that descends the eastern slope of the ,rocky ,mountains in ,montana1 ,wyoming and ,colorado1 and flows north-eastward over the plains4 ,its effects are most pronounced in winter1 when it brings about a very sudden rise in the temperature--in extreme cases as much as forty degrees in fifteen minutes6 ,it causes snow to vanish as if by magic1 and is appropriately nicknamed the snow-eater4 ,cloudburst is merely a picturesque name for a very heavy shower2 usually a thunder-shower4 ,illustration3 ,,in ,,the ,,wake ,,of ,a ,,tornado ,the tornado destroyed a house and barn1 but left a path in the center with practically no harm done ,west ,india hurricanes occasionally visit the ,united ,states1 especially in the late summer and early autumn4 ,these storms begin as violent cyclones of small extent 7#cjj to #fjj miles in diameter71 usually somewhere east of the ,west ,indies1 sweep in a long curve across the ,caribbean ,sea1 and then turn north1 either passing up along the ,atlantic ,coast or crossing the ,gulf of ,mexico into the southern ,united ,states4 ,soon after entering the temperate zone they increase in size and diminish in violence1 but are still vigorous enough on reaching the ,gulf or ,south ,atlantic ,coast to cause great devastation4 ,low-lying shores are often inundated by the immense waves they generate4 ,cold waves are the rapid and severe falls in temperature that sometimes occur in winter1 especially at the front of an anticyclone4 ,warnings of these occurrences1 issued by the ,weather ,bureau twenty-four to thirty-six hours in advance1 often result in the saving of millions of dollars' worth of merchandise susceptible to damage by freezing4 ,frosts in the spring and autumn are also predicted with great success1 to the immense advantage of farmers1 market-gardeners1 and horticulturists4 ,the practice of smudging or heating orchards1 now so widespread1 is usually carried on under the advice of the ,weather ,bureau1 which gives prompt notice to the orchardist when such precautions are in order4 ,the bureau publishes charts showing the average and extreme dates of the last frost in spring and the first frost in autumn for all parts of the country4 ,illustration3 ,,looking ,,down ,,on ,a ,,sea ,,of ,,fog ,,from ,,mt4 ,,tamalpais1 ,,california ,a fog is a cloud resting on the surface of the earth4 ,in the ,united ,states fog is commonest along the northern and middle parts of the ,atlantic and ,pacific ,coasts4 ,in the interior of the country1 especially the western part1 it is of rare occurrence1 the average number of days a year with fog being less than ten4 ,lastly--weather fallacies are rife4 ,indian summer is merely a type of mild1 hazy1 heavenly weather that prevails intermittently during our long ,american autumns4 ,the equinoctial storm is a myth2 the climate has not changed anywhere within the span of a human lifetime 7one year differs from another1 but there is no progressive or permanent change72 and the moon has nothing whatever to do with ,,the ,,weather4 ,,supplementary ,,reading ,,climate ,,and ,,weather ,by ,h4 ,n4 ,dickson ,,american ,,weather ,by ,a4 ,w4 ,greely ,,weather ,,science ,by ,r4 ,g4 ,k4 ,lempfert ,,some ,,facts ,,about ,,the ,,weather ,by ,w4 ,marriott ,second edition4 ,,meteorology ,by ,w4 ,i4 ,milham ,the latest general textbook on the subject in ,english4 ,,forecasting ,,weather ,by ,w4 ,n4 ,shaw ,,elementary ,,meteorology ,by ,f4 ,waldo ,consult also the numerous publications of the ,united ,states ,weather ,bureau1 which will be found in most public libraries4 999999 ,information concerning the above books and articles may be had on application to the ,editor of ,the ,mentor4 ,,the ,,open ,,letter ,what is lightning and what causes it8 ,the question came to us a few days after we had made announcement of a ,weather number of ,the ,mentor4 ,it was a natural question1 for lightning is the most sensational of all weather phenomena4 ,it has always had a fearful sort of fascination for humanity4 ,to the ancients it came as a bolt of wrath from the hand of ,jove4 ,to the fire-worshipers it was a warning message4 ,to parched travelers it was a bright promise1 for it heralded the coming of rain4 ,to the superstitious it was a signal flash from the spirit world4 ,and to those of nervous temperament it was a highly disturbing phenomenon producing emotions varying from uneasiness and alarm to hysteria4 ,the question then1 ,what is lightning and what causes it8 has an interest for all4 ,i referred it to ,mr4 ,talman1 the author of the ,mentor article on ,the ,weather4 ,his reply follows4 99 99 99 99 99 ,not so many generations ago 'natural philosophers' thought that inflammable gases1 exhaled from the earth1 took fire spontaneously in the air1 and that this was lightning4 ,the idea also prevailed--and it is not yet quite extinct--that a stroke of lightning involved the hurling down from the sky of a mass of rock1 called a 'thunderbolt4' ,in the eighteenth century people became quite familiar with the process of generating1 by friction1 a mysterious something called 'electricity1' which1 when it passed from one body to another through a small layer of intervening air1 produced sparks4 ,several philosophers noticed the resemblance between these sparks and lightning4 ,it remained1 however1 for ,benjamin ,franklin to prove that lightning was really an electrical discharge on a large scale4 ,the experiments by which he proposed to demonstrate this were successfully performed1 first by others1 in ,france1 and then1 by ,franklin himself1 at ,philadelphia4 ,with the aid of his famous kite he drew down from a thundercloud a little of the 'electrical fluid' 7as it was then called71 and produced tiny sparks from an iron key at the lower end of the wet kite-string4 ,we do not even yet know what electricity is1 but we know a great deal about the way it behaves and the effects it produces4 ,there are two kinds of electricity1 which we call positive and negative4 ,a body is said to be charged when it has an excess of either kind1 and the two kinds have a tendency to unite and neutralize each other's effects4 ,thunderclouds become heavily charged with electricity4 ,we are not quite sure how this happens1 but it is now commonly believed that the strong uprising currents of air that occur in the storm1 in the process of breaking up the water-drops in the cloud also separate positive from negative electricity2 leaving the former in excess in the part of the cloud next to the earth1 and carrying the latter far aloft4 ,by a process called 'induction' the positive charge in the cloud draws an excess of negative electricity to the surface of the ground underneath4 ,the stronger the contrast between these opposite charges1 the harder they try to break through the interposing barrier of the air 7which is a poor conductor of electricity7 and to neutralize each other4 ,at length they succeed in doing so4 ,a powerful stream of electricity flows for an instant between cloud and earth4 ,its passage heats the air and makes it luminous--just as the passage of an electric current heats the filament of an electric lamp and makes it luminous4 ,this is lightning4 ,these discharges occur not only between the clouds and the earth1 but also1 and probably more often1 between clouds charged with opposite kinds of electricity4 ,the sudden expansion of the heated air along the path of the discharge affects our ears just as does the sudden expansion of the air at the mouth of a gun when it is fired4 ,in each case a wave is sent through the air in all directions from the place of disturbance1 and our ear-drums are set in vibration4 ,that is thunder4 99 99 99 99 99 ,take courage then1 you timid ones1 who wince in the lightning's flash and tremble under the thunder's roll4 ,thunder is simply a vibration of your ear drums--and1 when you hear the thunder1 be assured1 all danger is over4 ,signature3 ,w4 ,d4 ,moffat ,,editor ,,the ,,mentor ,,association ,,established ,,for ,,the ,,development ,,of ,a ,,popular ,,interest ,,in ,,art1 ,,literature1 ,,science1 ,,history1 ,,nature1 ,,and ,,travel ,,the ,,plan ,,of ,,the ,,association ,the purpose of ,the ,mentor ,association is to give its members1 in an interesting and attractive way the information in various fields of knowledge which everybody wants and ought to have4 ,the information is imparted by interesting reading matter1 prepared under the direction of leading authorities1 and by beautiful pictures1 reproduced by the most highly perfected modern processes4 ,the object of ,the ,mentor ,association is to enable people to acquire useful knowledge without effort1 so that they may come easily and agreeably to know the world's great men and women1 the great achievements and the permanently interesting things in art1 literature1 science1 history1 nature1 and travel4 ,the purpose of the ,association is carried out by means of simple readable text and beautiful illustrations in ,the ,mentor4 ,the annual subscription is ,three ,dollars1 covering ,the ,mentor ,course1 which comprises twenty-four numbers of ,the ,mentor in one year4 ,,the ,,mentor ,,is ,,published ,,twice ,a ,,month ,,by ,,the ,,mentor ,,association1 ,,inc41 ,,at #eb ,,east ,,nineteenth ,,street1 ,,new ,,york1 ,n4 ,y4 ,,subscription1 ,,three ,,dollars ,a ,,year4 ,,foreign ,,postage #ge ,,cents ,,extra4 ,,canadian ,,postage #ej ,,cents ,,extra4 ,,single ,,copies ,,fifteen ,,cents4 ,,president1 ,,thomas ,h4 ,,beck2 ,,vice-,,president1 ,,walter ,p4 ,,ten ,,eyck2 ,,secretary1 ,w4 ,d4 ,,moffat2 ,,treasurer1 ,,robert ,m4 ,,donaldson2 ,,asst4 ,,treasurer ,,and ,,asst4 ,,secretary1 ,j4 ,s4 ,,campbell ,,the ,,mentor ,,association1 ,,inc4 #eb ,,east #aith ,,street1 ,,new ,,york ,n4 ,y4 ,,the ,,mentor ,the ,mentor ,index ,an index to ,the ,mentor has been prepared1 and is now ready4 ,every number of ,the ,mentor1 from ,serial ,no4 #a through #ajf1 has been indexed4 ,it is a complete1 concise1 and accurate grouping of all the subjects treated in ,the ,mentor1 under three headings--the gravure pictures1 the monographs1 and ,the ,mentor articles4 ,every subject is carefully indexed so that the information desired may be quickly and easily found4 ,every member of ,the ,mentor ,association should own this index1 and every member will want to own it1 particularly if his or her file of back numbers is complete4 ,the index is the same size as ,the ,mentor and similar in style1 so that it may be bound in with the numbers of ,the ,mentor themselves4 ,the price is twenty-five cents a copy4 ,it would be advisable to place your order at once1 as the first edition is limited4 ,send all orders to ,,the ,,mentor ,,association #eb ,,east ,,nineteenth ,,street ,,new ,,york1 ,n4 ,y4 ,,make ,,the ,,spare ,,moment ,,count ,,contributors ,,to ,,the ,,mentor ,these are the men and women who make ,the ,mentor--all of them eminent authorities in their special fields of knowledge4 ,,john ,c4 ,,van ,,dyke1 ,professor of the ,history of ,art1 ,rutgers ,college1 and ,author of many books4 ,,hamilton ,w4 ,,mabie1 ,editor of ,the ,outlook1 and ,author and ,literary ,critic4 ,,dwight ,l4 ,,elmendorf1 ,traveler and ,lecturer4 ,,albert ,,bushnell ,,hart1 ,professor of ,government1 ,harvard ,university4 ,,dr4 ,,william ,t4 ,,hornaday1 ,director of the ,new ,york ,zoological ,park1 and ,author of many nature books4 ,,robert ,e4 ,,peary1 ,discoverer of the ,north ,pole4 ,,prof4 ,,charles ,e4 ,,fay1 ,tufts ,college1 and ,first ,president of the ,american ,alpine ,club4 ,,william ,,winter1 celebrated ,critic and ,author4 ,,james ,,huneker1 ,author and ,critic4 ,,gustav ,,kobbe1 ,art ,critic of the ,new ,york ,herald1 and ,author of many books4 ,,lorado ,,taft1 well-known ,american ,sculptor and ,author4 ,w4 ,j4 ,,henderson1 ,music ,critic of the ,new ,york ,sun1 and ,author of many books4 ,,stephen ,,bonsal1 ,author and ,war ,correspondent4 ,e4 ,h4 ,,forbush1 ,state ,ornithologist of ,massachusetts1 and ,author of many books4 ,,burges ,,johnson1 ,professor1 ,vassar ,college1 ,author and ,humorist4 ,,arthur ,,hoeber1 ,artist1 ,critic and ,author4 ,,daniel ,c4 ,,beard1 ,author1 ,artist1 and celebrated ,naturalist4 ,,samuel ,,isham1 distinguished ,art ,critic and ,author4 ,h4 ,,addington ,,bruce1 ,author of many books4 ,,prof4 ,c4 ,r4 ,,richards1 ,director of ,cooper ,union1 ,new ,york ,city4 ,,robert ,m4 ,mc,e,l,r,o,y1 ,professor of ,american ,history1 ,princeton ,university4 ,,clarence ,,ward1 ,professor of ,architecture1 ,rutgers ,college4 ,,ida ,m4 ,,tarbell1 well-known ,magazine ,writer and ,author of many books4 ,,henry ,t4 ,,finck1 ,music ,editor of the ,new ,york ,evening ,post1 and ,author of various books4 ,j4 ,t4 ,,willing1 ,art ,editor and ,author4 ,,george ,w4 ,,botsford1 ,professor of ,ancient ,history1 ,columbia ,university4 ,h4 ,e4 ,,krehbiel1 ,music ,critic of the ,new ,york ,tribune1 and ,author of various books4 ,f4 ,j4 ,,mather1 ,jr41 ,professor of ,art and ,archeology1 ,princeton ,university4 ,,frederick ,,palmer1 ,celebrated ,war ,correspondent1 and ,author of various books4 ,,henry ,,woodhouse1 ,editor of ,flying1 and an authority on aeronautics4 ,,william ,a4 ,,coffin1 ,n4 ,a41 well-known ,artist and ,author4 ,,kenyon ,,cox1 ,n4 ,a41 distinguished ,artist1 ,author and ,instructor in art4 ,,esther ,,singleton1 ,author of many books4 ,,walter ,,prichard ,,eaton1 well-known ,magazine ,writer and ,author of various books4 ,,john ,k4 ,,mumford1 ,author and ,expert on rugs4 ,,belmore ,h4 ,,browne1 ,artist1 ,author and ,explorer4 ,,frank ,,weitenkampf1 of the ,new ,york ,public ,library1 ,expert ,in ,prints4 ,w4 ,j4 ,,holland1 ,director of the ,carnegie ,museum1 ,pittsburgh1 ,pa41 and distinguished ,naturalist4 ,,dean ,c4 ,,worcester1 noted ,traveler and ,lecturer and ,author4 ,,aymar ,,embury1 well-known ,architect and ,writer on architectural subjects4 ,c4 ,f4 ,,talman1 of the ,united ,states ,weather ,bureau1 ,washington4 ,complete ,your ,,mentor ,,library ,,subscriptions ,,always ,,begin ,,with ,,the ,,current ,,issue ,the following numbers of ,the ,mentor ,course1 already issued1 will be sent postpaid at the rate of fifteen cents each4 ,serial ,no4 #a4 ,beautiful ,children in ,art #b4 ,makers of ,american ,poetry #c4 ,washington1 the ,capital #d4 ,beautiful ,women in ,art #e4 ,romantic ,ireland #f4 ,masters of ,music #g4 ,natural ,wonders of ,america #h4 ,pictures ,we ,love to ,live ,with #i4 ,the ,conquest of the ,peaks #aj4 ,scotland1 the ,land of ,song and ,scenery #aa4 ,cherubs in ,art #ab4 ,statues ,with a ,story #ac4 ,story of ,america in ,pictures3 ,the ,discoverers #ad4 ,london #ae4 ,the ,story of ,panama #af4 ,american ,birds of ,beauty #ag4 ,dutch ,masterpieces #ah4 ,paris1 the ,incomparable #ai4 ,flowers of ,decoration #bj4 ,makers of ,american ,humor #ba4 ,american ,sea ,painters #bb4 ,story of ,america in ,pictures3 ,the ,explorers #bc4 ,sporting ,vacations #bd4 ,switzerland3 ,the ,land of ,scenic ,splendors #be4 ,american ,novelists #bf4 ,american ,landscape ,painters #bg4 ,venice1 the ,island ,city #bh4 ,the ,wife in ,art #bi4 ,great ,american ,inventors #cj4 ,furniture and ,its ,makers #ca4 ,spain and ,gibraltar #cb4 ,historic ,spots of ,america #cc4 ,beautiful ,buildings of the ,world #cd4 ,game ,birds of ,america #ce4 ,story of ,america in ,pictures3 ,the ,contest for ,north ,america #cf4 ,famous ,american ,sculptors #cg4 ,the ,conquest of the ,poles #ch4 ,napoleon #ci4 ,the ,mediterranean #dj4 ,angels in ,art #da4 ,famous ,composers #db4 ,egypt1 the ,land of ,mystery #dc4 ,story of ,america in ,pictures3 ,the ,revolution #dd4 ,famous ,english ,poets #de4 ,makers of ,american ,art #df4 ,the ,ruins of ,rome #dg4 ,makers of ,modern ,opera #dh4 ,durer and ,holbein #di4 ,vienna1 the ,queen ,city #ej4 ,ancient ,athens #ea4 ,the ,barbizon ,painters #eb4 ,abraham ,lincoln #ec4 ,george ,washington #ed4 ,mexico #ee4 ,famous ,american ,women ,painters #ef4 ,the ,conquest of the ,air #eg4 ,court ,painters of ,france #eh4 ,holland #ei4 ,our ,feathered ,friends #fj4 ,glacier ,national ,park #fa4 ,michelangelo #fb4 ,american ,colonial ,furniture #fc4 ,american ,wild ,flowers #fd4 ,gothic ,architecture #fe4 ,the ,story of the ,rhine #ff4 ,shakespeare #fg4 ,american ,mural ,painters #fh4 ,celebrated ,animal ,characters #fi4 ,japan #gj4 ,the ,story of the ,french ,revolution #ga4 ,rugs and ,rug ,making #gb4 ,alaska #gc4 ,charles ,dickens #gd4 ,grecian ,masterpieces #ge4 ,fathers of the ,constitution #gf4 ,masters of the ,piano #gg4 ,american ,historic ,homes #gh4 ,beauty ,spots of ,india #gi4 ,etchers and ,etching #hj4 ,oliver ,cromwell #ha4 ,china #hb4 ,favorite ,trees #hc4 ,yellowstone ,national ,park #hd4 ,famous ,women ,writers of ,england #he4 ,painters of ,western ,life #hf4 ,china and ,pottery of ,our ,forefathers #hg4 ,the ,story of ,the ,american ,railroad #hh4 ,butterflies #hi4 ,the ,philippines #ij4 ,great ,galleries of the ,world3 ,the ,louvre #ia4 ,william ,m4 ,thackeray #ib4 ,grand ,canyon of ,arizona #ic4 ,architecture in ,american ,country ,homes #id4 ,the ,story of ,the ,danube #ie4 ,animals in ,art #if4 ,the ,holy ,land #ig4 ,john ,milton #ih4 ,joan ,of ,arc #ii4 ,furniture of the ,revolutionary ,period #ajj4 ,the ,ring of the ,nibelung #aja4 ,the ,golden ,age of ,greece #ajb4 ,chinese ,rugs #ajc4 ,the ,war of #ahab #ajd4 ,great ,galleries of the ,world3 ,the ,national ,gallery1 ,london #aje4 ,masters of the ,violin #ajf4 ,american ,pioneer ,prose ,writers #ajg4 ,old ,silver #ajh4 ,shakespeare's ,country #aji4 ,historic ,gardens of ,new ,england ,,numbers ,,to ,,follow ,july #ae4 ,,american ,,poets ,,of ,,the ,,soil4 ,by ,burges ,johnson1 ,associate ,professor of ,literature1 ,vassar ,college4 ,august #a4 ,,argentina4 ,by ,e4 ,m4 ,newman1 ,lecturer and ,traveler4 99 99 99 99 99 ,illustration3 ,,central ,,office ,,of ,,the ,,united ,,states ,,weather ,,bureau1 ,,washington1 ,d4 ,c4 ,,weather ,,services ,,at ,,home ,,and ,,abroad ,monograph ,number ,one in ,the ,mentor ,reading ,course ,posted up in public offices1 in hotel corridors1 and other conspicuous places in our cities1 the official weather map is a familiar sight4 ,even more familiar is the official weather forecast1 displayed1 as a rule1 on the first page of the daily newspaper1 and sent broadcast over the country on the little brown cards which one may see in the village postoffice as well as in the city drug-store4 ,when a great storm sweeps over land or sea1 detailed official reports concerning its progress and characteristics are published in the daily press4 ,when a lawsuit involves a dispute as to the temperature or the state of the sky on a certain day1 the official weather records are consulted4 ,how much do you know about the branch of the national government that is charged with the duty of keeping watch of the weather--recording its vagaries as they occur1 and also predicting them1 as far as is humanly possible8 ,besides its office in ,washington1 where more than two hundred persons are constantly employed1 the ,weather ,bureau has about two hundred stations1 manned by professional meteorologists and observers4 ,one of these will be found in almost every large city1 while some are in towns of very modest importance4 ,a regular ,weather ,bureau station is well worth a visit4 ,the instrumental equipment of these stations is almost superhuman in the accuracy with which it sets down on paper the chronicle of weather happenings from day to day and from moment to moment4 ,little less marvelous is the system by means of which weather information--past1 present and future--is disseminated from these official foci4 ,the postoffice1 the telephone1 the telegraph 7wire and wireless7 are all pressed into service to the fullest extent--especially in giving timely notice of approaching storms and other destructive forms of weather4 ,these agencies are supplemented by visible and audible signals1 in the shape of flags1 lanterns1 railway whistles and so forth4 ,contrary to popular belief1 the ,weather ,bureau does not exist primarily for the purpose of telling the public 7with a considerable margin of uncertainty7 whether it will be advisable1 on the morrow1 to carry an umbrella or wear an overcoat4 ,the important work of the ,bureau is twofold4 ,it consists1 first1 in the prediction of those atmospheric visitations1 such as storms1 floods1 and cold waves1 which endanger life and property on a large scale2 and1 second1 in the maintenance of the records that form the basis of climatic statistics4 ,in both these directions the ,bureau splendidly justifies its existence4 ,our national weather service was founded in #ahgj1 and for twenty years was maintained by the ,signal ,corps of the ,army4 ,in #ahij it was established on the present basis1 as the ,weather ,bureau of the ,department of ,agriculture4 ,most civilized countries possess official services for the observation and prediction of weather1 though no other is organized on quite so grandiose a scale as ours4 ,the ,british ,meteorological ,office1 the ,prussian ,meteorological ,institute1 the ,central ,meteorological ,bureau of ,france1 and the ,central ,physical ,observatory of ,petrograd are among the leading institutions of this character in the ,old ,world4 ,admirable weather services also exist in ,india1 ,japan1 ,australia1 ,canada1 ,argentina and elsewhere4 ,illustration3 ,a ,,simple ,,weather ,,station ,,meteorological ,,instruments ,monograph ,number ,two in ,the ,mentor ,reading ,course ,the history of meteorological instruments dates back at least as far as the fourth century before the ,christian era1 when the depth of rainfall was measured in ,india by some form of gauge4 ,we again hear of rain-gauges being used in ,palestine in the first century of the present era4 ,thermometers with fixed scales were used in ,italy in the seventeenth century1 and the great ,galileo1 born in ,pisa in #aefd1 took part in perfecting these instruments4 ,wind-vanes were known to the ancients4 ,the earliest one of which we have any record surmounted the famous ,tower of the ,winds at ,athens4 ,in the ,middle ,ages the weathercock became the usual adornment of church steeples4 ,the barometer was invented by ,torricelli in #afdc4 ,most meteorological instruments1 however1 are of quite recent origin1 and this is true especially of these types of apparatus that make automatic records1 thus replacing1 to a large extent1 the human observer4 ,our picture on the other side of this sheet shows the instruments used by the co-operative observers of the ,weather ,bureau4 ,these observers1 of whom there are about #d1ejj1 well distributed over the country1 serve the government without pay1 and their painstaking observations have alone made possible a detailed survey of our climate4 ,in the picture we see1 on the right1 an ordinary rain-gauge1 and1 on the left1 a thermometer-screen containing two thermometers2 viz41 a maximum thermometer1 for recording the highest temperature of the day1 and a minimum thermometer1 for recording the lowest4 ,the screen1 which is of wood1 painted white1 serves to shield the instruments from the rays of the sun1 while permitting free ventilation4 ,under these conditions the thermometers show the temperature of the air2 whereas when exposed to direct sunlight a thermometer shows the temperature acquired by the instrument itself1 and this may differ materially from the air temperature4 ,in contrast to this simple equipment1 we find at a regular meteorological station1 or observatory1 an impressive collection of apparatus for observing and recording nearly all the elements of weather4 ,the pressure of the air is measured by the mercurial barometer1 and registered continuously by the barograph2 the temperature of the air is automatically recorded by the thermograph4 ,other self-registering instruments maintain continuous records of the force and direction of the wind1 the amount and duration of rainfall1 the duration of sunshine1 the humidity of the air1 etc4 ,there are also instruments for measuring evaporation1 the height and movement of clouds1 the intensity of solar radiation1 the elements of atmospheric electricity1 and various other phenomena of the atmosphere4 ,illustration3 ,a ,,majestic ,,cumulus ,,cloud ,,clouds ,,and ,,rainfall ,monograph ,number ,three in ,the ,mentor ,reading ,course ,the ,international ,cloud ,classification1 now generally used by meteorologists1 is an amplification of one introduced by an ingenious ,english ,quaker1 ,luke ,howard1 in the year #ahjc4 ,howard distinguished seven types of cloud1 to which he gave the ,latin names cirrus1 cumulus1 stratus1 cirro-cumulus1 cirro-stratus1 cumulo-stratus1 and nimbus4 ,in passing1 it may be of interest to note that1 a few years after ,howard's classification was published1 an attempt was made by one ,thomas ,forster to introduce popular equivalents of these terms4 ,forster proposed to call cirrus curlcloud1 cumulus stackencloud1 stratus fallcloud1 etc4 ,in other words1 he assumed that because ,howard's names were ,latin in form they were unsuitable for use by the layman1 and therefore needed to be supplemented by ,english names--although the proposed substitutes were1 on the whole1 somewhat longer and more difficult to pronounce than the originals6 ,a parallel undertaking would be an attempt to discourage the public from calling the wind-flower anemone1 or virgin's bower clematis4 ,forster's superfluous names have never taken root in our language4 ,the highest clouds--cirrus and cirro-stratus--are feathery in appearance1 and consist of minute crystals of ice4 ,their altitude above sea-level averages about five miles1 but is frequently much greater than this4 ,all other clouds are composed of little drops of water--not hollow vesicles of water1 as was once supposed4 ,neither crystals nor drops actually float in the air4 ,they are constantly falling with respect to the air around them1 though1 as the air itself often has an upward movement1 the cloud particles are not always falling with reference to the earth4 ,in any case1 their rate of fall depends upon their size1 and in the case of the smaller particles is very slow4 ,under some conditions the particles evaporate before reaching the earth1 while under others they maintain a solid or liquid form and constitute rain or snow4 ,a fog is a cloud lying at the earth's surface4 ,rainfall is one of the most important elements of climate1 chiefly because of its effects upon vegetation4 ,it is measured in terms of the depth of water that would lie on the ground if none of it ran off1 soaked in1 or evaporated2 and this is1 in practice1 determined by collecting the rain1 as it falls1 in a suitable receiver1 or rain-gauge4 ,usually the gauge is so shaped as to magnify the actual depth of rainfall1 in order to facilitate measurement4 ,snow is measured in two ways2 first1 as snow1 and1 second1 in terms of its water equivalent4 ,the latter measurement is commonly effected by melting the snow and pouring it into the rain-gauge1 where it is measured as rain4 ,by this expedient we are enabled to combine measurements of rain and snow1 in order to get the total precipitation of a place during a given period4 ,nature is notoriously partial in her distribution of this valuable element over the earth4 ,a region having an average annual rainfall of less than ten inches is normally a desert1 though irrigation or dry-farming methods may enable its inhabitants to practice agriculture4 ,the heaviest average annual rainfall in the ,united ,states 7not including ,alaska7 is about #acf inches1 in ,tillamook ,county1 ,oregon4 ,the rainiest meteorological station in the world is ,cherrapunji1 ,india1 with an average of about #dbf inches per annum4,b ,b ,this is the latest official record4 ,there are several rain-gauges at ,cherrapunji1 and the average amount of rain collected by any one of them varies considerably with the length of the record4 ,hence the widely divergent values of the rainfall at this famous station published in encyclopaedias and other reference books4 ,illustration3 ,,the ,,observatory ,,on ,,monte ,,rosa ,,the ,,outposts ,,of ,,meteorology ,monograph ,number ,four in ,the ,mentor ,reading ,course ,the expression used in our title seems a fitting one to apply to a number of meteorological observatories and stations maintained for the benefit of science in regions remote from the comforts and conveniences of civilization4 ,some are on the summits of lofty mountains1 the ascent of which is laborious and even perilous4 ,others are situated in the bleak wildernesses of the circumpolar zones4 ,public attention has all too rarely been called to the heroism and self-sacrifice of the men who constitute the staffs of these lonely outposts4 ,the institution shown in our gravure--officially known1 in honor of the ,dowager ,queen of ,italy1 as the ,regina ,margherita ,observatory--crowns the summit of ,monte ,rosa1 on the northern ,italian frontier1 and is #ad1ifj feet above sea-level4 ,it is devoted not only to meteorological investigations1 but to studies of the physiological effects of great altitudes and various other researches1 and is open to the savants of all nationalities who are courageous enough to scale the second highest summit of the ,alps4 ,it is habitable for only about two months2 viz41 from the middle of ,july to the middle of ,september4 ,each year a temporary telephone line is constructed connecting the observatory with the plains of ,italy4 ,this is the highest telephone line in the world1 and its installation is an arduous undertaking4 ,a permanent line is impossible1 on account of the shifting of the glaciers and snowfields on which the poles must be erected4 ,there is also a meteorological observatory on ,mont ,blanc1 but it is not at the summit and is not quite so high as that on ,monte ,rosa4 ,the solar observatory which once stood at the very top of ,mont ,blanc no longer exists4 ,the ,united ,states ,signal ,service 7now the ,weather ,bureau7 formerly maintained observatories on ,pike's ,peak 7#ad1acd feet7 and ,mount ,washington 7#f1bhj feet74 ,the loftiest of meteorological stations was1 however1 that formerly operated by ,harvard ,college ,observatory on the summit of ,el ,misti1 ,peru 7#ai1bjj feet74 ,for a number of years the ,united ,states ,weather ,bureau maintained a large and important observatory at ,mount ,weather1 at the crest of the ,blue ,ridge1 near ,bluemont1 ,virginia4 ,in the ,old ,world one of the most famous of mountain meteorological observatories was that which stood on ,ben ,nevis 7#d1djf71 the highest summit in the ,british ,isles4 ,this was closed in #aijd4 ,if the conditions of life at these high-level stations are such as to repel any but the ardent lover of science1 the same is true in even greater measure of those endured by the little band of meteorologists who man the observatory maintained by the government of ,argentina at ,laurie ,island1 in the ,south ,orkneys1 on the verge of the ,antarctic4 ,every year a party of four is sent out from ,buenos ,aires to spend a year of exile in this inhospitable spot1 which is generally ice-bound1 and has not even wireless communication with the rest of the world4 ,this station has been in operation since #aijd4 ,the staff1 which is changed each year1 has embraced men of several nationalities--,scotch1 ,american and others4 ,far within the ,arctic ,circle two meteorological observatories are maintained in ,spitsbergen2 but these are1 at least1 connected with the world by radiotelegraphy4 ,if the hopes of explorer ,peary are accomplished1 an observatory will1 one of these days1 be established at the ,south ,pole4 ,illustration3 ,,launching ,a ,,meteorological ,,kite ,,the ,,air ,,above ,,us ,monograph ,number ,five in ,the ,mentor ,reading ,course ,meteorologists are not content to limit their investigations to the stratum of air lying close to the earth's surface4 ,even before the demands of the aeronaut for information concerning the structure and phenomena of the atmosphere far overhead became pressing1 many efforts had been made to secure such information1 in view of its important bearing upon many scientific problems4 ,as long ago as the year #aghd a balloonist1 equipped with various meteorological instruments1 made an ascent from ,london and brought back an interesting series of observations1 which were communicated to the ,royal ,society4 ,for more than a century the manned balloon was the principal means of sounding the upper atmosphere4 ,nowadays1 as a rule1 the meteorologist1 instead of going aloft in person1 sends up a kite or a balloon to which are attached automatically registering instruments4 ,when the aerial vehicle returns to earth its record shows in detail the conditions encountered during the journey4 ,everybody remembers how ,franklin brought lightning from the clouds2 but it is a far cry from the simple apparatus that served ,franklin's purpose to the box kite of modern meteorology4 ,science has perfected the kite almost beyond recognition4 ,it has been shorn of that crucial feature of the schoolboy article1 the tail4 ,even the kite string has become several miles of steel piano wire1 wound around the drum of a power-driven winch1 with elaborate apparatus for recording the force of the pull1 and the angles of azimuth and altitude4 ,captive balloons are sometimes used for similar investigations4 ,when1 however1 it is desired to attain great altitudes the meteorologist has recourse to the so-called sounding-balloon1 which is not tethered to the earth4 ,this is usually made of india-rubber1 and when launched is inflated to less than its full capacity4 ,as it rises to regions of diminished air pressure it gradually expands1 and finally bursts at an elevation approximately determined in advance4 ,a linen cap1 serving as a parachute1 or sometimes an auxiliary balloon which does not burst1 serves to waft the apparatus1 with its delicate self-registering instruments1 gently to the ground4 ,this commonly happens many miles--sometimes two hundred or more--from the place of ascent4 ,attached to the apparatus is a ticket offering the finder a reward for its return1 and giving instructions as to packing and shipping4 ,sooner or later it usually comes back2 though often months after it falls4 ,indeed1 the large percentage of records recovered1 even in sparsely settled countries1 is not the least remarkable feature of this novel method of research4 ,the instruments attached to sounding-balloons register the temperature of the air1 the barometric pressure1 and sometimes the humidity4 ,by means of the sounding-balloon the air is explored to heights of twenty miles and more6 ,the records obtained by means of these balloons have1 within the past fifteen years1 completely revolutionized our ideas concerning the upper atmosphere4 ,still another device employed by meteorologists is the pilot-balloon4 ,this is also a free balloon1 but carries no meteorological instruments4 ,its motion in the air is followed by means of a theodolite1 and it serves to show the speed and direction of the wind at different levels4 ,during the winter of #aiab-ac a pilot-balloon sent up from ,godhavn1 ,greenland1 by a ,danish exploring expedition reached the unprecedented altitude of more than #bd miles4 ,illustration3 ,,the ,,effects ,,of ,,snow ,,and ,,ice--,,the ,,campus1 ,,princeton ,,university ,,our ,,winters ,monograph ,number ,six in ,the ,mentor ,reading ,course ,in the year #agha ,thomas ,jefferson wrote in his ,notes on ,virginia3 ,a change of climate is taking place very sensibly4 999999 ,snows are less frequent and less deep4 ,they do not often lie below the mountains more than one1 two or three days1 and very rarely a week4 ,the snows are remembered to have been formerly frequent1 deep1 and of long continuance4 ,the elderly inform me that the earth used to be covered with snow about three months in every year4 ,probably long before the white man came to ,america the patriarchs of the ,indian tribes regaled the young men and maidens gathered about the campfire with reminiscences of the deep snows that prevailed in a previous generation4 ,in short the old-fashioned winter is a perennial myth1 perpetuated by a familiar process of self-delusion6 ,the occasional periods of abundant snow make a more lasting impression upon our minds than the long intervals in which this element was scarce or lacking4 ,the resulting misconception is promptly dissipated when we consult the weather records1 which1 in some parts of the country1 extend back more than a century1 and prove that there has been no actual change in the climate within the period they embrace4 ,of course the erroneous idea is1 in some cases1 due to the fact that one's childhood was spent in a part of the country in which the snowfall is normally heavier than in that where one has recently lived4 ,the average yearly snowfall over the ,new ,england ,states1 ,new ,york1 and the borders of the ,great ,lakes is from #ej to #ajj inches1 and upward4 ,over the ,north ,central ,states it is much less4 ,in the ,southern tier of ,states and along almost the whole of our ,pacific coast snow is a rarity4 ,the heaviest snowfall in this country probably occurs in the high ,sierra ,nevada of ,california1 near the border of ,nevada4 ,in some places in these mountains more than #dj feet of snow falls in an average winter1 while more than #fe feet has been recorded in extreme cases4 ,here it is a common occurrence for one-story houses to be buried1 to the eaves1 or above4 ,the ,southern ,pacific ,railway1 which intersects this region1 has built #cb miles of snowsheds1 at a cost of #db1jjj a mile over single track and #fe1jjj a mile over double track4 ,in an average year #aej1jjj is spent on these sheds in upkeep and renewals4 ,flat-roofed houses are unknown in this vicinity2 all roofs are gabled at a sharp angle to shed the snow4 ,a picturesque feature of our ,american winters is the ice storm1 so enthusiastically described by ,mark ,twain3 444 ,when a leafless tree is clothed with ice from the bottom to the top--ice that is as bright and clear as crystal2 when every bough and twig is strung with ice-beads1 frozen dew-drops1 and the whole tree sparkles cold and white1 like the ,shah of ,persia's diamond plume4 ,such is the artist's view of the phenomenon2 but1 alas6 these same ice storms cause endless inconvenience and heavy expense every winter to the electrical industries1 by breaking wires4 ,,prepared ,,by ,,the ,,editorial ,,staff ,,of ,,the ,,mentor ,,association ,,illustration ,,for ,,the ,,mentor1 ,,vol4 #d1 ,no4 #aj1 ,,serial ,no4 #aaj ,,copyright1 #aiaf1 ,,by ,,the ,,mentor ,,association1 ,,inc4