,,transcriber',s ,,note ,italic text is denoted by underscores4 ,bold text is denoted by equal signs4 ,footnote anchors are denoted by number1 and the footnotes have been placed at the end of the book4 ,the tables in this book are best viewed using a monospace font4 ,some minor changes to the text are noted at the end of the book4 ,,the ,,new ,,air ,,world ,illustration3 ,,fig4 #d4--;,,instrument ,,shelter4 ,frontispiece4 7,page #ff7 ,,the ,,new ,,air ,,world ,the ,science of ,meteorology ,simplified ,,by ,,willis ,,luther ,,moore1 ,,sc4,d41 ,,ll4,d4 ,,professor ,,meteorology ,,george ,,washington ,,university1 ,,eighteen ,,years ,,chief ,,united ,,states ,,weather ,,bureau ,illustration3 7colophon7 ,,boston ,,little1 ,,brown1 ,,and ,,company #aibb ,copyright1 #aibb1 ,,by ,,little1 ,,brown1 ,,and ,,company4 ,all rights reserved ,published ,october1 #aibb ,,printed ,,in ,,the ,,united ,,states ,,of ,,america ,,affectionately ,,dedicated ,,to ,a ,,friend ,,of ,,many ,,and ,,pleasant ,,years ,a ,,beloved ,,teacher ,,and ,a ,,great ,,chemist ,,dr4 ,,charles ,e4 ,,munroe1 ,,ph4,d4 ,,introduction ,the author's 8,descriptive ,meteorology0 7,appleton1 #aiad7 is designed for the teaching of those who intend to make ,meteorology a profession4 ,this book is planned for the reading of those who desire to know something of the wonders of the ,new ,air ,world into which man is just now entering1 for those who desire to become weatherwise and make forecasts for themselves1 and to apply their knowledge to their business1 their health1 and their happiness2 and for the reading of the more advanced pupils of the public schools4 ,so far as possible technical terms are avoided and an effort made to tell a simple story that will awaken curiosity and lead the reader to wish to know more and more of the mysteries of the atmosphere1 of which practically nothing was known at the time of the landing of the ,pilgrims1 ,torricelli not having discovered the barometer until twenty-three years later4 ,it will be made plain how atmospheric air was formed1 how long it will remain1 whither it will go1 how it is heated1 cooled1 and lighted2 where and how storms1 cold waves1 clouds1 frosts1 and fair-weather conditions originate and how move2 how the cyclone1 the tornado1 and the thunderstorm may be recognized on the ,daily ,weather ,map of the ,government and their future activities forecast2 how a fund of simple yet wonderful information that will be of inestimable value may be acquired by any intelligent person4 ,the author acknowledges courtesies extended to him by ,prof4 ,charles ,f4 ,marvin1 present chief of the ,weather ,bureau1 and by ,r4 ,h4 ,weightman1 chief clerk of the ,bureau1 in the matter of securing several important illustrations2 and like favors extended to him by ,d4 ,appleton and ,company1 ,john ,wiley ,sons1 and the ,taylor ,instrument ,company1 of ,rochester1 ,n4 ,y4 ,w4 ,l4 ,m4 ,,august1 #aibb ,,contents ,,chapter ,,page ,,introduction vii ,i ,,atmospheres ,,of ,,the ,,earth1 ,,the ,,sun1 ,,and ,,the ,,planets #a ,,ii ,a ,,synoptic ,,picture ,,of ,,the ,,air #g ,,iii ,,explorations ,,of ,,the ,,atmosphere #ah ,,iv ,,earth',s ,,four ,,atmospheres #bi ,v ,,light1 ,,heat1 ,,and ,,temperature #dh ,,vi ,,the ,,advantage ,,of ,,taking ,,weather ,,observations ,,and ,,applying ,,them ,,to ,,one',s ,,personal ,,needs #fd ,,vii ,,frost #he ,,viii ,,wind ,,and ,,pressure ,,of ,,the ,,globe #ih ,,ix ,,how ,,to ,,forecast ,,from ,,the ,,daily ,,weather ,,map #aab ,x ,,climate #afa ,,xi ,,how ,,climate ,,is ,,modified ,,and ,,controlled #ahh ,,xii ,,civilization ,,follows ,,the ,,storm ,,tracks #bac ,,xiii ,,has ,,our ,,climate ,,changed8 #bbe ,,xiv ,,climates ,,for ,,health ,,and ,,pleasure #bde ,,xv ,,condensation #bhb ,,xvi ,,development ,,of ,,the ,,american ,,weather ,,service #bia ,,index #cjg ,,list ,,of ,,figures ,instrument ,shelter 7,figure #d7 ,frontispiece ,,figure ,,page #a4 ,winter and ,summer ,vertical ,temperature ,gradients1 in degrees ,centigrade and ,fahrenheit #ab #b4 ,showing light from lamp a passing into dust-free air at b1 and passing out at c without illuminating the interior #df #c4 ,standard ,weather ,bureau ,kite #fd #e4 ,comparison of the ,thermometer ,scales #fg #f4 ,dry and ,wet ,bulb ,thermometers #fh #g4 ,mercurial ,barometer #gh #h4 ,continuous records of the temperature from #d ,p4,m4 to #i ,a4,m4 #hg #i4 ,continuous records of the temperature #e feet and #ce feet above ground on a tower in a pear orchard #ie #aj4 ,average dates of last killing frost in ,spring #if #aa4 ,average dates of first killing frost in ,fall #ig #ab4 ,trade wind circulation #ii #ac4 ,average surface winds and pressure of the globe #ajb #ad4 ,how winds would blow into a cyclone on a non-rotating earth #ajh #ae4 ,deflection of wind due to earth's rotation #aji #af4 ,annual1 summer1 and winter wind velocities with altitude #aaj #ag4 ,tornado ,cloud #ade #ah4 ,the ,st4 ,louis ,tornado of ,may #bg1 #ahif1 ,shot a ,pine ,scantling through the ,iron ,side of the ,eads ,bridge #adg #ai4 ,the ,st4 ,louis ,tornado of ,may #bg1 #ahif1 ,shot a ,shovel ,six ,inches into the ,body of a ,tree #adg #bj4 ,the ,st4 ,louis ,tornado ,drove ,straws ,one half ,inch into ,wood #adi #ba4 ,equinoxes1 ,march #ba and ,september #bb #afc #bb4 ,summer ,solstice1 ,june #ba #afd #bc4 ,winter ,solstice1 ,december #ba #afd #bd4 ,winter and ,summer ,solstices1 and the ,equinoxes #afe #be4 ,as angle of incidence decreases from #ij to #aj the heat received on upper end of blocks is spread over greater area at bottom1 and its temperature diminished #afe #bf4 ,altitude attained by ,sun at midday and length of its track above the horizon at the ,summer and ,winter ,solstices and at the two ,equinoxes #afg #bg4 ,summer day and ,summer night temperatures in the same narrow valley #bjd #bh4 ,average ,monthly ,temperature and ,rainfall of ,typical ,places in ,north ,america #bjg #bi4 ,average ,monthly ,temperature and ,rainfall of ,typical ,places in the ,old ,world #bjh #cj4 ,changes in ,climate in ,california during the ,christian ,era #bcg #ca4 ,snow ,crystals #bhf ,,list ,,of ,,charts ,,chart ,,page #a4 ,high and ,low ,centers of ,action and ,prevailing ,winds of the ,globe for ,july #ii #b4 ,high and ,low ,centers of ,action and ,prevailing ,winds of the ,globe for ,january #ajj #c4 ,winter ,storm1 ,december #ae1 #ahic1 #h ,a4,m4 #aad #d4 ,winter ,storm1 ,december #ae1 #ahic1 #h ,p4,m4 #aaf #e4 ,winter ,storm1 ,december #af1 #ahic1 #h ,a4,m4 #aah #f4 ,cold ,wave ,zones1 ,march to ,november4 ,amount of ,fall and ,verifying ,limit #abg #g4 ,cold ,wave ,zones1 ,december1 ,january1 and ,february4 ,amount of ,fall and ,verifying ,limit #abh #h4 ,lowest ,temperatures in the ,united ,states1 #ahga-aiac #abi #i4 ,number of ,cold ,waves1 #aijd-aiad1 ,inclusive #acj #aj4 ,storm ,tracks for ,august for ,ten ,years #acb #aa4 ,storm ,tracks for ,february for ,ten ,years #acd #ab4 ,average ,maximum ,temperature for ,july #aie #ac4 ,ocean ,currents #aif #ad4 ,mean ,annual ,isotherms #bjj #ae4 ,normal ,wind ,direction and ,velocity for ,january and ,february #bjb #af4 ,normal ,wind ,direction and ,velocity for ,july and ,august #bjd #ag4 ,map of ,climatic ,energy #bba #ah4 ,density of ,population in the ,united ,states1 #aiaj #bbb ,,the ,,new ,,air ,,world ,,chapter ,i ,,atmospheres ,,of ,,the ,,earth1 ,,the ,,sun1 ,,and ,,the ,,planets ,how ,atmospheres ,are ,formed4 ,once there were no such things on the earth as hills and mountains1 singing brooks1 roaring rivers and vast oceans2 and the delicately hued landscape1 with its winding roads1 hedges1 flowers1 green fields1 and golden grain1 had not evolved from the atmosphere4 ,the earth had not yet cooled down to the condition of a solid crust1 everything that the eye now sees existed in the form of invisible gases1 or as clouds incandescent with white heat4 ,fiery blasts swirled over the face of the earth4 ,storms a million times more powerful than the most destructive ,west ,indian hurricane of the present day moved through the indescribably hot atmosphere1 throwing down not rain as we understand it1 but liquid earth and metal1 as their rising clouds ascended and cooled4 ,it is difficult for the human mind to grasp the wonders of this4 ,small planets cool quicker than large ones and sooner come to the conditions of a crust and to a temperature suitable for the development of the various forms of life4 ,atmosphere of the ,sun4 ,to the unaided eye it appears as a smooth1 bright1 quiescent sphere1 but the telescope reveals millions of agitations and hundreds of red flames that shoot outward to distances of hundreds of thousands of miles4 ,one can form no adequate picture of the convulsions of the atmosphere of the sun4 ,during eclipses1 when the intense glare of its center is obscured1 hydrogen flames may be seen darting outward for as much as a million miles4 ,lifeless ,planets4 ,the larger a planet the longer is the time that must elapse before the hot vapors of rock and metal1 which largely compose its early atmosphere1 cool and congeal into a crust1 leaving as a residual an atmosphere of such heat1 density1 and composition as to permit of the beginnings of the forms of life that have inhabited the world4 ,before the sun can reach this condition1 an indescribable period will have elapsed1 its light will have gone out1 its heat will have ceased to reach the earth and the other planets in quantities sufficient to maintain life1 the earth will have been dead millions of years1 and the sun itself will only receive heat and light from the feeble rays of the stars that1 unlike itself1 have not yet ceased to shine4 ,but even then the sun ever must remain dead1 for there is no external source whence it may receive heat4 ,no vegetation can adorn it1 no water flow upon its surface1 neither can the foot of any man press its soil4 ,jupiter1 and perhaps ,neptune1 ,uranus1 and ,saturn1 have hot atmospheres still in violent agitation1--molten surfaces composed of all kinds of matter1 from which bubble and boil off hot clouds of vapor that surge about in huge eddies or cyclonic storms1 and that here and there are shot outward in tongues of fire4 ,the earth millions of years ago had a similar atmosphere4 ,but when the heat energy of these vaporous planets wanes1 and they cool down1 as the earth did many years ago1 the simplest forms of life cannot be evolved upon them1 for they are too far away from the sun to receive life-giving heat4 ,mars receives less than half the intensity of the solar rays that come to the earth1 ,jupiter only #j4jcg1 ,saturn #j4jaa1 ,uranus #j4jjc1 and ,neptune #j4jja4 ,in due time--some hundreds of millions of years--the cooling of the sun will leave the earth to freeze and all life to become extinct1 unless1 perchance1 the oxygen of the air is so far absorbed by its rocks1 or filtered away into space1 as to destroy life before that time4 ,no matter what may be the achievements of the human mind1 what wonderful civilizations may be developed1 what powerful empires created1 or what wonderful secrets of creation discovered1 it seems certain that these all will pass away1 and finally the surface of the earth be as if man never lived4 ,the dust of ages will wipe out and obliterate every trace and vestige of the operations of life4 ,silence1 cold1 and darkness will then reign supreme4 ,but the time of this is indescribably far off in the future1 and man will have ample opportunity to develop to the highest mental and spiritual estates of which he has inherent possibilities4 ,the moon already is dead4 ,if it is formed of matter abandoned by the earth1 as we believe1 it once must have had an atmosphere1 a portion of which was absorbed by its rocks as it cooled1 and the remainder lost as the result of the low power of attraction of so small a body1 which is insufficient to prevent the darting molecules of the gases of its air from shooting off into space4 ,the absence of an atmospheric covering allows the heat from the sun to escape almost as rapidly as it is received2 and the long nights of the moon 7each as long as fourteen of our days7 during which the sun's rays are entirely cut off1 permit the temperature of the dark side to fall to something like -#djj ,f4 ,how ,atmospheres ,are ,maintained and ,how ,lost4 ,the processes of nature are always adding to the various gases of the atmosphere in some ways1 and transforming or taking from them in other ways4 ,on the earth the loss and the gain are so nearly equal as to maintain at present a nearly constant condition4 ,marked changes have taken place1 however1 in long geologic periods4 ,our early atmosphere probably contained large quantities of carbon dioxide which were absorbed by the rank vegetable growth that now forms the coal beds of the earth1 and the slowly cooling rocks that constitute the crust took in large quantities of oxygen2 in fact1 nearly one half of the weight of the crust of the earth is composed of the latter element4 ,in consequence it may be said that our present atmosphere is what remained after the earth had absorbed its gases nearly to depletion1 and after the lighter gases1 like hydrogen and helium1 which seem to have too great molecular velocity to be imprisoned by the earth's attraction of gravitation1 had been lost in space4 ,gases that cannot be held by the moon may be imprisoned by the earth and those that can escape from the earth may be held by the larger planets4 ,height of the ,earth's ,atmosphere4 ,exact computation has shown that if the air were the same density at all elevations1 which it is not1 it would extend upward a distance of only five miles4 ,from laws that are well understood it is known that at a height of thirty miles the atmosphere is only about one hundredth as dense as it is at the surface of the earth1 and that at fifty miles it is too light to manifest a measurable pressure4 ,the oxygen ceases at about thirty miles and the nitrogen at about fifty miles1 the water vapor being restricted below the five-mile level4 ,the appearance of meteors1 which are rendered luminous by rushing into the earth's atmosphere1 and whose altitudes have been determined by simultaneous observations at several stations1 reveals the presence of hydrogen and helium at a height of nearly two hundred miles4 ,,chapter ,,ii ,a ,,synoptic ,,picture ,,of ,,the ,,air ,how much do you know of the great arial ocean on the bottom of which you live and in which human beings are just beginning to fly8 ,its variations of heat1 cold1 sunshine1 cloud1 and tempest materially affect not only the health and happiness of man but his commercial and industrial welfare1 and yet few know more than little of the wonders of the life-giving medium that so intimately concerns them4 ,at the ,height of ,two ,hundred ,miles4 ,here is only the invisible1 the intangible ether which1 while too tenuous to be detected or measured by any appliances of man1 is supposed to transmit the rays of the sun4 ,these rays1 coming in the form of many different wave lengths1 and with widely differing velocities of vibration1 produce a multitude of phenomena as they are absorbed by or pass through the air1 or as they reach the surface of the earth4 ,the longer and slower waves are converted into heat1 the shorter and more rapid ones into light1 and the minutest movements probably into electricity4 ,oxygen and nitrogen1 which form the greater part of the atmospheric gases1 absorb comparatively little of the solar rays1 while water vapor1 which constitutes a little more than one per cent4 of the atmosphere and which remains close to the earth1 absorbs large quantities4 ,from the fact that one half of the atmosphere1 including nearly all of its water vapor1 lies below an elevation of three and one half miles1 it becomes evident that the greater part of the absorption of the sun's rays must take place in the lower strata4 ,on clear days the atmosphere absorbs nearly one half of the sun's heat rays2 the remainder reaches the surface of the earth1 warms it and in turn is radiated back into the air1--with this difference3 that as earth radiation the wave motion of the rays is longer and slower than it was when the rays entered our atmosphere as solar radiation4 ,in this slower form the rays are the more readily absorbed4 ,the atmosphere is thus warmed largely from the bottom upwards1 which accounts for the perpetual freezing temperatures of high mountain peaks1 although they are nearer the sun than are the bases from which they rise4 ,at the ,height of ,one ,hundred ,miles4 ,the temperature at this altitude must be that of outside space1 probably #dei ,f4#a below zero4 ,air liquefies at #cab below1 and therefore it cannot exist in the gaseous state in a region having a lower temperature4 ,when it liquefies it has the color and general appearance of water1 and about the same specific gravity4 ,when a piece of steel and a lighted taper are brought together inside of a vessel filled with liquid air1 the dense supply of oxygen makes combustion so rapid that the hard metal burns like tinder4 ,at the ,height of ,fifty ,miles4 ,there is enough air here to refract light slightly1 as at twilight1 and to render luminous the meteors that rush with fearful velocity against its widely scattered molecules4 ,at this distance from the earth there probably is no more air than would be found under the receiver of the best air pump1 and1 the reader will be surprised to learn1 darkness is practically complete1 although the hour may be midday1 for there are no dust motes to scatter and diffuse and render visible the light rays of the sun4 7,see ,chapter ,,iii47 ,the ,darkness of ,outer ,space4 ,it may be proven by taking an inclosed volume of air1 freeing it of dust motes1 of which there are millions per cubic centimeter1 and then trying to illuminate it2 it will be found that no matter how powerful the light directed into it1 it remains wholly dark4 ,when one looks upward on a clear day1 he apparently sees the whole universe illuminated2 but in point of fact only the thin stratum of the earth's air in which he lives is illuminated4 ,outer space is practically without temperature or light4 ,the rays of the sun do not become either light or heat or electricity until they encounter the molecules of the air1 or the invisible dust motes1 or the cloud particles near the earth and through interference are transmuted from etheric vibrations into other forms of energy4 ,the ,bacteria of ,disease and of ,putrefaction4 ,these rapidly diminish in number with elevation1 and on the tops of the highest mountain peaks practically none are found4 ,mid-ocean also shows but few4 ,at the ,height of ,twenty-five ,miles4 ,air1 light as it is1 has still sufficient density to obstruct the passage of the minutest wave lengths of light1 and here probably begins to be appreciable the blue tint of the heavenly vault4 ,at this short distance from the earth there must be a deathlike stillness1 for there is no medium sufficiently dense to transmit sound4 ,two persons could not hear each other speak1 even if they could live in this rare atmosphere1 which they could not4 ,here is eternal peace and no apparent motion1 for storms and ascending and descending currents cease long before this level is reached4 ,the cold is intense and daylight but a feeble illumination4 ,there are no clouds4 ,isothermal ,stratum ,entered at the ,height of ,seven ,miles4 ,we know that the temperature decreases rapidly with ascent--about one degree for each three hundred feet--until the top of the storm level is reached1 at about seven miles1 when a most wonderful discovery is made3 the thermometer no longer falls as the aviator rises1 or as balloons float to great altitudes carrying self-registering instruments4 ,the temperature remains practically stationary1 so far as exploration has been made1 which is to the height of over nineteen miles4 ,major ,r4 ,w4 ,schroeder1 ,u4 ,s4 ,a41 flew in an aroplane to #cf1jjj feet and recorded a temperature of #fi below zero4 ,we have named this region above storms the ,isothermal stratum4 7,see ,figure #a47 ,its temperature everywhere is about #gj below zero and it changes only about six degrees between winter and summer4 ,of course we must assume that ultimately the temperature shades away to practically nothing as outer space is reached4 ,illustration3 ,,fig4 #a4--,winter and ,summer ,vertical ,temperature ,gradients1 in degrees ,centigrade and ,fahrenheit4 ,scientific and inventive genius is becoming so skillful in harnessing the forces of nature to man's desires that it is reasonable to anticipate that within a quarter of a century or less human beings will be nearly as numerous in the air as insects1 they will remain aloft longer1 and sail to vastly greater distances and to higher altitudes4 ,in time dirigible ships may sail for days and possibly for weeks in the pure air aloft1 carrying millions of passengers4 ,at a ,height of ,one and ,one ,half ,miles4 ,there is little difference in the temperatures of day and night1 except that the coolest time of the twenty-four hours is during daytime and not at night1 as would be most naturally supposed4 ,this is important information to an aviator or to the pilot of a balloon4 ,at an ,altitude of ,one ,thousand ,feet4 ,in free air at the hottest time in midsummer's heat1 the air is found to be as much as fifteen degrees lower than that at the ground4 ,almost within arm's length of the streets of great inland cities there is a cool and healthful atmosphere when humanity is sweltering and dying from heat below4 ,some youth who is reading this may develop the genius that will lift up whole city blocks into this cool and healthful region4 ,open steel work below1 the first level at one or two thousand feet above the hot streets1 express elevators to carry passengers1 and the climate of the cool mountain air is accessible to those who now live in discomfort at low populous centers4 ,man is just beginning to disport himself in the hitherto trackless wilderness of the air4 ,certain it is that the hanging gardens of ,babylon will be outdone in the ,twentieth ,century and the eyrie of the eagle left far below by those who will live a part of their time in elevated structures having bases resting upon the earth2 or who will fly to great distances aloft and remain at whatever altitude furnishes them the most pleasant and beneficial conditions1 and that they may thus remain not only for days but for weeks without returning to the surface of the earth4 ,only during recent years have we realized how thin is the stratum of air next to the earth which has sufficient heat and moisture for the inception1 growth1 and maturity of animal and vegetable life4 ,the raising of the instrument shelter at the ,new ,york station of the ,u4 ,s4 ,weather ,bureau from an elevation of one hundred and fifty feet above the street to an altitude of three hundred feet has caused an apparent lowering of the mean annual temperature of two and one half degrees4 ,air is so elastic and its density diminishes so rapidly with elevation that nearly one half of the weight of the entire mass of the atmosphere lies below the level of the top of ,pike's ,peak1 which has a height of a little less than three miles above sea level4 ,it presses with a weight of about fifteen pounds per square inch of surface1 and its pressure is exerted in all directions1 upward as well as downward4 ,an ordinary man sustains a pressure of over one ton on each square foot of his surface1 but as the air penetrates all portions of his body and exercises a pressure outward as well as inward he feels no inconvenience4 ,if his body could be so tightly sealed that no air could enter and if then the air of the interior should be removed with a pump1 his body instantly would be crushed to a shapeless pulp4 ,a cubic foot of atmospheric air weighs one and one third ounces4 ,water is #ggc times1 and mercury ten thousand times1 as dense as air4 ,but air is a more ponderable substance than many suppose2 an ordinary lecture hall forty by fifty feet and thirty feet from floor to ceiling contains two and one half tons of air at freezing temperature4 ,it would contain less at a higher temperature1 because heat expands its volume2 it would contain more at a lower temperature1 because cold contracts its volume4 ,everything ,evolved from the ,air4 ,air is so common that we seldom stop to consider the magnitude of the force it exerts or the grandeur wrought by this invisible architect of nature4 ,in the great cycle of world building--birth from the nebul1 growth1 maturity1 decay1 disintegration1 death1 and then possibly back again to the nebul--the atmosphere1 be it light and tenuous as at present1 or be it filled with the hot vapors of earth and metal1 is the vehicle and the medium of the builder1 transporting and transmuting1 in mysterious ways and to wondrous forms1 the materials of planets4 ,its work as a builder may be further illustrated by showing that the body of man itself returns not to the earth earthy1 as we have been taught1 but largely to the air whence it came4 ,decomposition is but the liberation of the ariform gases of which it is mainly composed2 the residue is but a handful that goes back to mother earth4 ,let us take the dried corn plant2 weigh it1 then burn it in a closed vessel so that none of the ashes can blow away4 ,continue the burning until the ashes are perfectly white and it will be found that the weight of the ashes is only about one twentieth of the weight of the great stalk1 ear1 and foliage we began with4 ,what has become of all the rest8 ,the fire has destroyed it1 you say4 ,no1 we can destroy nothing4 ,remember that2 we can destroy nothing that the ,creator has made1 neither matter nor force4 ,the fire has simply changed the form of the plant2 the nineteen twentieths that have disappeared have gone back to the air whence they came4 ,thus we see that the body of man1 the cereal and fruit that furnish him food1 the structure that gives him shelter1 aye1 the many things that please the eye3 the landscape1 the beautiful flowers1 the green fields1 the babbling brooks1 even the rose blush on the maiden's cheek1#b--really come from this wonderful fluid surrounding the earth1 and well may it be said that the queen of life rides upon the crest of the wind4 ,,chapter ,,iii ,,exploration ,,of ,,the ,,atmosphere ,,discoveries ,,as ,,valuable ,,to ,,the ,,future ,,as ,,those ,,made ,,by ,,columbus ,an entire new world is coming within the range of man's vision4 ,its possibilities for adding to the health and happiness of mankind are almost limitless4 ,the geographic poles have been conquered and the jungles of ,africa traversed2 and deep borings have been made into the bowels of the earth until heat has arrested further progress4 ,the further exploration of both regions is of the utmost importance to the coming age4 ,it is not at all visionary to assume that the heat of the earth's interior in near time will furnish the power necessary to do the drudgery of mankind1 give warmth and light to habitations1 and operate transportation systems2 and the ,new ,world ,above offers pure1 electrified1 and highly stimulating air into which helium-inflated dirigible balloons will sail1 and in which they will remain not only days but weeks or longer1 with their multitudes of people4 ,while the use of kites and balloons in sending automatic meteorological instruments far aloft has revealed more of the wonders of this hitherto uncharted wilderness of cold and partial or total darkness than the general public is aware of1 only the outer fringes of the mysterious regions above the clouds and the storms have been penetrated4 ,when the manufacture of helium1 a noncombustible gas almost as light as hydrogen1 becomes more general1 as seems imminent in the ,united ,states1 the dirigible balloon may successfully compete with the railroads in the carrying of long-distance passengers4 ,the recent loss of over forty lives in ,england by the collapse of the dirigible ,,zr#b probably was largely if not entirely due to the explosion and fire of the hydrogen gas with which the ship was inflated4 ,a decade ago1 in a number of ,chautauqua lectures1 the writer invariably was greeted with looks of incredulity when he prophesied that within ten years travelers of the air would take breakfast at the ,waldorf-,astoria in ,new ,york and afternoon tea on the banks of the ,thames4 ,and yet the ocean already has been crossed by an aroplane in continuous flight1 and in the near future it is highly probable that arial navigation will be safer than travel by rail or automobile4 ,the hitherto inaccessible parts of the earth will be sailed over and closely scrutinized1 while travelers enjoy the comforts that heretofore have been associated with ,pullman service4 ,in #ahfb the ,english meteorologist ,glashier ascended in a balloon to about the same height as that attained by ,major ,r4 ,w4 ,schroeder1 ,u4 ,s4 ,a41 who achieved a more difficult feat when he flew in an aroplane to over #cf1jjj feet4 ,and at ,dayton1 ,ohio1 celebrated as the home of the ,wright brothers1 on ,september #bh1 #aiba1 ,lieutenant ,john ,a4 ,macready1 ,u4 ,s4 ,a41 reached the unprecedented height of #dj1hjj feet4 ,these are the extreme altitudes to which human beings ever have attained1 but they are only the beginning of explorations into a vast and largely unknown and extremely cold region1--one in which darkness increases with elevation until at the outer limits of the atmosphere no illumination whatever exists4 ,the high eastward wind and #fi below zero encountered by ,schroeder are conditions that already had been revealed by the work done at the research station of the ,weather ,bureau1 at ,mount ,weather1 ,virginia1 and at other stations in this country and in ,europe1 by the sending up of instruments unaccompanied by observers4 ,under the direction of the writer the ,weather ,bureau liberated numerous small hydrogen gas balloons in the ,rocky ,mountain region1 to which were attached automatic instruments registering the temperature1 pressure1 and the hygrometric conditions4 ,as they came eastward in the atmospheric drift that always prevails above the storms in the middle latitudes they attained to great altitudes1 one balloon reaching #ai4a miles1 the greatest altitude ever reached at that time by the appliances of man4 ,ultimately the balloons would explode as they expanded under the influence of decreasing air pressure and the case of instruments would descend slowly under a parachute designed to open at the right moment4 ,the barometer traced a line on a paper cylinder revolving by clock works1 as did the thermometer4 ,the thermogram gave the temperature that corresponded with the varying elevation shown by the tracing of the barogram4 ,in #ahih1 twelve hundred observations were made with kites by the observers of the ,weather ,bureau at seventeen stations selected by the writer1 during the six warm months from ,may to ,october4 ,it was surprising to find the temperature often losing as much as fifteen degrees with the first thousand feet ascent during middays of extremely hot periods4 ,the average decrease in temperature per thousand feet elevation for all stations for all times1 and at all elevations up to #ebhj1 was #d4 ,for over five years kites were used nearly every day in the year at ,mount ,weather to carry instruments aloft to heights ranging from two to four and one half miles1 and at times to keep the apparatus up during all hours of the day1 so that a comparison could be made of the difference between day and night temperatures4 ,there is but little difference between midday and midnight at only a few thousand feet above the earth4 ,few are aware that the rectangular kite of the weather man was the forerunner of the aroplane of the aviator4 ,in #aijc1 while directing wireless experiments in the sending of messages at ,roanoke ,island1 ,north ,carolina1 the writer saw the ,wright brothers1 or their representatives1 lying flat upon the lower planes of what appeared to be ,weather ,bureau kites and gliding in the air from the top of the sand dunes4 ,this was the beginning of real flight by man4 ,the ingenuity of the ,wrights transformed the weather man's kite1 strengthened it1 took out the ends1 hitched on a rudder1 and when the petrol engine had developed sufficient power with a given weight1 installed it1 and flew4 ,in the future the meteorologist and the aviator will be closely associated4 ,with a sufficient number of weather observations made by aviators simultaneously and well distributed over the ,united ,states it will be possible to construct a daily weather map on some high level--say the three-mile level--similar to the map now based upon sea level4 ,the pressure1 temperature1 wind direction1 clouds1 and rainfall would be recorded and charted for the upper region clear across the continent4 ,three miles is about halfway to the top of cyclonic storms and probably in the region of greatest activity4 ,more accurate forecasts would be possible by the study of this additional weather chart4 ,this coperation of the bird man and the weather man in studying the geography of the new air world will mark an epoch in meteorological science as far-reaching in its consequences as were the discovery of the barometer by ,torricelli and the uncovering of the principles of the thermometer by ,galileo1 the former of which was not known until more than twenty-three years after the landing of the ,pilgrims at ,plymouth ,rock4 ,thus swiftly does the mind of man to-day explore the hidden recesses of nature's mysteries1 and with each conquest carry itself to a higher realm of existence4 ,in the not distant future1 more storm warnings may be issued by the ,weather ,bureau for ships of the air than for those of the sea1 for the navigation of the air must play an increasing and important part in the coming activities of the world4 ,science is becoming so skilled in the harnessing of the forces of nature to man's desires and in the development of mechanical appliances1 that it is reasonable to anticipate the possibility that long-distance travel over land or ocean ultimately will be almost entirely confined to the air4 ,as the result of the explorations of the atmosphere made by the institution at ,mount ,weather there was ready for our fighting air men at the front1 immediately on our entry into the ,world ,war1 a fund of useful information concerning a region that but a short time before was entirely uncharted4 ,the instruments carried by the exploring kites and balloons had keen scientific eyes and they recorded on clock-timed cylinders what they saw4 ,thus did the air pilot know much about the direction and the force of the wind that he would encounter as he rose1 the altitude where he would pass above clouds1 the degree of cold that he would encounter1 etc4 ,he was told that the temperature would fall about one degree for each three hundred feet of his ascent until he reached the top of the storm stratum at six or seven miles1 and that if he could reach that altitude he would observe a most wonderful phenomenon3 the temperature no longer would fall with gain in altitude2 he would enter a cold but an equally heated stratum1 without finding any temperatures lower than were encountered upon entering the region1 which is always about seventy degrees below zero4 ,if the arial explorer could stop his ship and keep it at an altitude of about one and one half miles for twenty-four hours he would be startled to find that the coolest time of the period was during the daytime1 not during the night1 as he had expected to find it4 ,in the future the traveler in the upper reaches of the atmosphere will carry oxygen and make the kind of air that he wishes to breathe1 and he will properly protect himself against the cold of his new world1 which he will find deficient in dust motes and doubtless entirely wanting in the bacteria of putrefaction and of disease4 ,there will be no clouds to obscure his vision2 no rain or snow4 ,he will not often ascend above the region where there are not some dust motes to scatter and diffuse a part of the solar rays and give him at least a partial illumination4 ,few persons are familiar with the simple problems of the air which have such important bearing on the distribution of man into realms above those he has been accustomed to occupy4 ,they do not know that the northwest wind brings physical energy and mental buoyancy because it has a downward component of motion that draws air from above1 where it is free of impurities1 and where high electrification has changed a considerable quantity of its oxygen into ozone1 in which condition it remains but a short time after reaching the lower potential near the earth's surface4 ,more people die under the influence of the south wind than under the influence of the north wind1 because the south winds hug the surface of the earth and become laden with impurities and are lacking in electrical stimulation4 ,when inventive man becomes more familiar with the ocean on the bottom of which he has heretofore lived1 he will not wait for the north wind to bring down to him the beneficial conditions that always exist higher up2 he will go after them and remain aloft as long as he desires to do so4 ,the further development of the dirigible balloon and the aroplane are among the most important duties that the engineer of the future owes to civilization2 and the meteorologist must establish the climatology of the vast untracked regions above the highest mountain peaks1 for here man will largely disport himself in the time to come4 ,the writer agrees with the opinion of ,major ,william ,r4 ,blair1 formerly of his staff when he was the head of the ,u4 ,s4 ,weather ,bureau1 but since the beginning of the ,world ,war the chief meteorological assistant of the ,chief ,signal ,officer of the ,u4 ,s4 ,army when he says3 8,with reference to air travel in the future3 the present stage of aircraft development seems to indicate that long non-stop traffic1 both freight and passenger1 in the air will be by means of lighter-than-air craft 7balloons74 ,these craft have much larger carrying capacity than any airplanes now designed and will travel across the continent over several prepared routes1 stopping only at important centers on these routes to discharge and take up passengers and freight4 ,it is believed that airplanes 7heavier-than-air craft7 will ply between these important centers and the outlying country about them1 thus acting as feeders to the main route1 over which the monstrous dirigibles will operate4 ,most transoceanic as well as transcontinental air traffic will probably be carried on in these large dirigible balloons40 ,lieutenant ,colonel ,henry ,b4 ,hersey1 who served through the ,world ,war in the ,aronautical ,service of the ,signal ,corps1 ,u4 ,s4 ,a41 and who also was associated with the writer in the management of the ,weather ,bureau1 says3 8,the fields of the dirigible and the air plane are separate and there is no conflict between the two4 ,for light loads1 great speed1 and quick manuvering1 the airplane is supreme4 ,for heavy loads1 long distance1 ability to remain in the air for great periods of time1 the dirigible is the only air craft that can fulfill the requirements4 ,dirigibles will soon be in use which can start from ,europe1 sail over ,new ,york1 and drop enough poison gas to kill thousands and make practically the whole city uninhabitable40 ,,chapter ,,iv ,,earth',s ,,four ,,atmospheres ,the earth has four important atmospheres and others of less importance4 ,the principal ones are oxygen1 nitrogen1 vapor of water1 and carbon dioxide1 each comporting itself as it would do if the others were not present4 ,there is space between the molecules of each gas1 and therefore it is easily compressed4 ,a doubling of its pressure reduces its volume one half4 ,composition of ,atmospheric ,air4 ,it is difficult for the mind to form a picture of the infinitely small molecules of the air4 ,let us therefore use terms and comparisons that will the more directly appeal to the human senses4 ,first let us imagine each molecule enlarged to the size of a small grain of sand4 ,then with the molecules from one cubic inch of air transformed into grains of sand we could build a roadway ten feet deep and one hundred feet wide extending from ,new ,york to ,san ,francisco4 ,may one still further grasp the idea of the atom1 many of which are required to make up the molecules8 ,if so1 the imagination has been stretched to its limits to enable the human mind to comprehend some of the simplest facts with regard to the wonderful fluid in which we live4 ,sir ,william ,thomson1 afterwards ,lord ,kelvin1 in endeavoring to give relative values that would appeal to the imagination1 said that if a drop of water were enlarged to the size of the earth1 the molecules of which it is composed would be no larger than cricket balls1 and the smallest about the size of small peas4 ,more than a thousand years before the birth of ,christ a great ,phnician philosopher believed that all matter--solids1 liquids1 and gases--was built up from infinitely small aggregations of atoms4 ,the learned men of ,greece enlarged upon his views but this philosophy passed into oblivion with the destruction of ,rome and the coming of the ,dark ,ages1 and it was not revived until about one hundred and fifty years ago4 ,the ancients could not prove their theory1 while we to-day can count the atoms and determine their size and motions2 and1 exceedingly small though they be1 we no longer believe them to be indivisible in structure4 ,on the contrary1 we know that each atom consists of particles of positive and negative electricity4 ,the negative electrons arrange themselves about a positive electron for a nucleus and1 rotating about it as if it were a central sun with planets1 constitute an atom4 ,all matter reduced to the ultimate electron is precisely alike4 ,the difference in matter is determined by the number of negative electrons that are attracted and held in place by the positive nucleus that is at the center of each atom of which a particular kind of matter is composed4 ,each of the ninety-two elements which we believe constitute the ninety-two different forms of simple matter has an atom with its own peculiar type of nucleus1 which nucleus differs from those of the others only in the amount of positive electricity it contains4 ,thus hydrogen1 the lightest of all gases1 whose weight is taken as unity in measuring the magnitude of other gases1 has a nucleus whose positive charge of electricity is only sufficient to attract one negative electron4 ,the next element1 helium1 has a nucleus with a double positive charge and consequently holds two electrons or planets to pay it homage4 ,in like manner the carbon atom contains six electrons2 oxygen1 eight2 aluminum1 thirteen2 nitrogen1 fourteen2 sulphur1 sixteen2 iron1 twenty-six2 copper1 twenty-nine2 silver1 forty-seven2 gold1 seventy-nine2 mercury1 eighty2 lead1 eighty-two2 bismuth1 eighty-three2 radium1 eighty-eight2 thorium1 ninety2 and uranium1 ninety-two4 ,the chemical union of these elementary forms of matter creates other forms4 ,for instance1 the union of two atoms of hydrogen and one of oxygen constitutes a molecule of water4 ,but the gases of the atmosphere are not in chemical union2 they exist in the form of a mechanical mixture1 each acting as though the others were not present4 ,it is important that this mixture of gases that constitutes our air be maintained in the right proportion4 ,only a slight difference in relative amounts might be disastrous to life4 ,an increase in the oxygen would stimulate mental and physical activities and hold the human faculties at a higher tension4 ,man would accomplish more in a given time1 but his span of life would be shortened2 and too great an increase in the proportion of this stimulating element would quickly terminate life4 ,conversely an increase in the nitrogen would render all life more lethargic and man would be slower to act and to think2 and too great an increase would smother every living thing4 ,in addition to the gases named1 the air contains small amounts of many other substances1--argon1 nitric acid1 ammonia1 ozone1 xenon1 krypton1 and neon2 as well as organic matter1 germs1 and dust in suspension4 ,over the land it contains sulphates in minute quantities1 and over the sea and near the seashore salt left from the evaporated spray4 ,the proportion of each component of the atmosphere by volume of the total atmosphere is different from its proportion by weight4 ,the percentages for the more abundant gases are as follows3 ,,by ,,volume ,,by ,,weight --------------------------------------- ,nitrogen #gh4jd #ge4df ,oxygen #bj4ii #bc4ai ,argon #j4id #a4cj ,carbon dioxide #j4jc #j4je ------------------------ #ajj4jj #ajj4jj ,nitrogen4 ,its principal functions are to dilute the oxygen and to furnish food to vegetation4 ,it is inert and does not manifest many marked chemical affinities4 ,its lack of activity is shown by the fact that it will neither support combustion nor burn4 ,oxygen4 ,oxygen1 unlike nitrogen1 is an active element that readily enters into chemical combination with many other elements1 and it is second in quantity to nitrogen4 ,with hydrogen it constitutes eight ninths1 by weight1 of water2 combined with other elements it constitutes forty to fifty per cent4 of the crust of the earth4 ,it burns so readily that were it not greatly diluted by an inert gas like nitrogen it would be difficult if not impossible to stop a conflagration when once started4 ,it is the vitalizing principle in all forms of life4 ,by its chemical union with carbon in the tissues of plants and animals it develops the energy manifested in their movements4 ,in the free air up to about seven miles high there is no variation in the proportion of oxygen4 ,but variations of marked importance to health and life occur in places where ventilation is restricted1 and especially where living creatures exist in closed rooms1 and where combustion occurs in confined places4 ,the following variations in percentages by volume were found in careful analyses by ,robert ,angus ,smith3 ,on the seashore of ,scotland1 #bj4ii2 open places in ,london1 #bj4ie2 in a small room where a petroleum lamp had been burning six hours1 #bj4hc2 pit of a theater at #aa3cj ,p4,m41 #bj4gd2 in a court room1 #bj4fe2 in mine pits1 #bj4ad4 ,he took samples from one mine that showed #ah4bg1 the candles going out when the amount had decreased to #ah4ej4 ,the absorption of oxygen by putrid matter and by living beings in the process of breathing1 and the giving out of carbon dioxide by both explain the deficiency of oxygen that is found over large cities1 which is more marked when the air is moving but little and where the city is located in a depression or near swampy lands4 ,both animals and plants inhale oxygen and exhale carbon dioxide with the unchanged nitrogen4 ,the process automatically proceeds both night and day4 ,it should not be confused with the opposite action of plants under the influence of sunlight in taking in and decomposing carbon dioxide and expelling pure oxygen4 ,carbon ,dioxide4 ,it forms the chief food supply of all green-leaved plants4 ,it is as necessary to the life of vegetation as is oxygen in the supporting of animal life4 ,in the ratio of seventy-seven to one hundred there is less of this gas present in the atmosphere in the winter than in the summer2 there also is a diurnal maximum and minimum4 ,in the open country the amount averages about #j4jce per cent4 by volume4 ,in cities the amount is considerably greater1 frequently rising to #j4jg1 and at times to #j4aj when the wind velocity is too low to scatter the excess amount that accumulates near the ground4 ,any quantity in excess of #j4jf per cent41 especially if combined with the organic matter exhaled from the lungs and from the pores of the skin by animals and man1 is injurious to health4 ,angus ,smith found as much as #j4cb per cent4 in crowded theaters1 and #b4ej in mines4 ,the latter amount soon would destroy animal life4 ,vegetation1 in addition to the inhalation of oxygen and the expiration of carbon dioxide at all hours1 absorbs the latter during the day1 and under the influence of sunlight the green granular matter that constitutes the chlorophyll of the cells of the leaves decomposes it1 the plant retaining the carbon and giving out the oxygen4 ,because of the absence of sunshine the chemical activities of the plant are altered at night and the absorption of carbon dioxide ceases2 therefore over the land the maximum amount occurs during the nighttime4 ,this gas is dissolved in sea water and given off with a rise in temperature1 which causes the maximum amount over oceans to occur at midday4 ,carbon dioxide is #a4ej times as dense as an equal volume of atmospheric air4 ,its greater density causes it to collect in mines1 sewers1 cellars1 and other low places1 unless there is forceful ventilation4 ,the ,american cold wave should be welcomed as the mighty scavenger of the air4 ,its high velocity and great density cause it to search into cracks1 crevices1 sewers1 and cellars and expel foul accumulations4 ,how sweet and clean the air smells and how vigorous physically and buoyant mentally one feels after a rain and high winds6 ,all nature smiles and every form of life adds its pan of joy4 ,rain washes out the carbonic acid gas 7carbon dioxide7 from the air1 with dust and other particles in suspension2 and the cold wave enters our places of habitation and drives out the thieving accumulations of poisonous gases that would rob us of health and maintain conditions of morbidity4 ,it cannot be too forcefully stated that oxygen1 the life-sustaining principle of the air1 decreases1 and carbon dioxide1 a poison1 increases in air that is breathed1 or in air in which lamps or gas jets are burning2 and that all places of habitation1 especially sleeping rooms1 should have a continuous supply of fresh air4 ,water ,vapor4 ,it is only a little over one half as dense as atmospheric air4 ,in the arid regions of the west it may form only a fraction of one per cent4 of the air by weight2 while in the humid regions in the eastern part of the ,united ,states it may constitute as much as five per cent4 ,the temperature being the same1 the same amount is required to saturate a given space1 whether it be a vacuum or whether it be filled with air4 ,air doubles its capacity for water vapor with each increase of eighteen to twenty degrees4 ,on a hot day in summer1 near large bodies of water1 it may constitute as much as one twentieth by weight of the lower air1 while on a cold day in winter it may form no more than one thousandth part4 ,when the air contains all the water vapor it can hold1 it is said to be saturated2 no more can be added to it until its temperature is raised1 and but a slight lowering of its temperature will precipitate a part of its water vapor in the form of dew1 frost1 rain1 hail1 or snow4 ,this is the reason it is usually called water vapor instead of a gas4 ,under the influence of heat that is below the freezing point1 ice and snow may be changed from the solid to the gaseous form1 and water vapor may be precipitated as frost or snow without passing through the liquid state4 ,the ,dew ,point is the temperature of saturation1--the temperature to which a body of air must be reduced before condensation can occur and some of its water vapor return to the liquid or solid state4 ,the ,relative ,humidity is expressed in percentages of the amount necessary to saturate4 ,at a temperature of #cb air may continue to increase its vapor of water until it contains #b4aa grains per cubic foot1 when it will be saturated and its relative humidity be one hundred per cent4 ,if this same air be suddenly raised in temperature to #ea its capacity per cubic foot will be increased to twice what it was at #cb1 the #b4aa grains will be equal to only one half the number necessary to saturate1 and the relative humidity be expressed by fifty per cent4 instead of one hundred per cent4 ,in this way does the capacity of air for water vapor increase4 ,thus it is seen that the relative humidity of the air may increase during the cooling of nighttime without the addition of any vapor of water1 and1 in fact1 with a decrease4 ,the increase of relative humidity after nightfall is greater in the country than in the city1 where the presence of pavements and brick buildings retards the loss of heat4 ,the ,absolute ,humidity is expressed in grains the cubic foot4 ,the hygrometer is employed to measure the amount of water vapor4 ,hydrogen is the lightest of all known gases4 ,its density in comparison with ordinary air is only 4#jfib4 ,it is combustible1 and when five volumes of atmospheric air are mixed with two volumes of hydrogen the mixture explodes when ignited4 ,it is supplied to the air by active volcanoes and in other ways1 but the speed of its molecules is such that it readily escapes from the earth's attraction and passes outward into space4 ,ozone 7,greek1 ozo1 ,i smell7 is highly electrified oxygen1 in which the molecules are broken up and reformed so as to contain additional atoms4 ,it is formed by the disruptive discharge of lightning and by the great amount of electricity present in the high levels of the atmosphere1 and possibly in minute quantities by the evaporation of fog and water near the earth4 ,it is always found in the presence of waterfalls and spraying fountains4 ,it is a powerful sanitary agent1 readily entering into union with decaying matter4 ,this fact accounts for the total absence of ozone from the air of large cities4 ,ozone1 in the minute quantities found in nature1 is healthful1 but when breathed in a condensed form it has a highly irritating effect on the mucous surfaces of the respiratory passages1 and the quantity is not large that will cause death4 ,the healthfulness of mountain air may be due largely to the increase with elevation in the quantity of ozone and electricity in the air1 as well as to the less number of disease germs and dust motes4 ,the invigorating effects of the crisp air of the frosty morning and of the cold wave in winter may be increased by the activities of ozone4 ,ozone has two daily maxima1 the principal one occurring between #d and #i ,a4,m4 ,the minima occur between #aj ,a4,m4 and #a ,p4,m41 and between #aj ,p4,m4 and midnight4 ,the winter furnishes an amount greatly in excess of the summer1 due not only to the less amount of decaying matter to take up the ozone in winter1 but to the higher and more persistent winds mixing the lower and upper air4 ,the amount is greater over the sea than over the land1 probably due to the absence of oxidizable matter1 which allows the ozone to accumulate over the water4 ,it is more abundant with westerly than with easterly winds1 due to the fact that westerly winds have a downward component of motion2 but if the westerly winds be weak and the easterly winds come from over a large body of water the conditions may be reversed4 ,microbes of the ,air4 ,the air transports vast armies of unseen workers4 ,some are enemies2 others are benefactors of the human family4 ,the useful varieties are energetic in clearing away the refuse of animal and vegetable life1 in fixing fertilizing gases in the soil1 in giving flavor to fruits and proper growth to leguminous crops1 in transforming the crudest must into the best claret1 and the poorest tobacco leaf into the fragrant ,havana2 in curing cheese and butter and fermenting beer1 and in a multitude of other useful employments4 ,the malevolent varieties1 if they gain lodgment in suitable human tissues before sunlight weakens their virility1 disseminate certain forms of disease4 ,in picking a permanent place of abode1 remember that there are many less disease microbes in the air of the open country than in that of the city1 and that few are found in the air of mountains1 or in that of the ocean4 ,the average number of bacteria in a cubic meter of air in the city of ,paris has been found to be #dgij1 while ten miles away in the country the number was only #cde4 ,accurate analyses of the air of crowded tenements always have shown large numbers of bacteria1 but the number was found to be small in well-ventilated city houses that let in an abundance of sunshine to their interiors4 ,it is better to have color in the cheeks of the occupants than in the furnishings of a house4 ,curtains and heavy drapery not only furnish a refuge for the microbes of disease1 but they may be so hung as to exclude the purifying sunshine4 ,the amount of sunshine is nearly as important as the quantity of air1 for most of the microbes of disease quickly die1 or are rendered less virulent1 under its influence4 ,bacteria exist in small numbers1 if at all1 at altitudes where snow forms1 but snow gathers them as it falls through the lower air4 ,ice contains bacteria1 but not in any such quantity as the water from which it freezes4 ,ice forms in the open at the surface of the water1 or about numerous small particles of matter in suspension1 which rise at once to the top as soon as the ice congeals about them in the form of a buoyant covering2 meanwhile sediment is continually settling to the bottom1 carrying bacteria with it4 ,ice forms more readily in quiet water1 where sedimentation has been most rapid1 and where1 therefore1 there are the fewest bacteria in position to be included4 ,more disease germs exist in river water in winter than in summer1 which may be due to the greater disinfecting power of the sun's rays during summer4 ,dust ,motes of the ,air4 ,as the earth pursues its course about the sun1 dust rains into its atmosphere from outer space4 ,meteors that are burned through the heat generated by striking into our air contribute to the supply1 as do volcanoes1 combustion1 spray from the ocean1 and matter lifted up by the action of the wind4 ,dust from the eruption of ,krakatoa was wafted entirely around the earth1 falling upon the decks of ships in all the seas of the world4 ,it affected the colors of the sky for two or three years after the explosion4 ,as in the case of microbes1 the number of dust particles is far greater in cities than in the country1 being least on high mountain tops and over the oceans4 ,the air in large cities invariably shows hundreds of thousands of dust motes to the cubic centimeter1 that of the village thousands1 and that of the open country some hundreds4 ,dust-free air is also germ-free4 ,many experiments have shown that air freed of dust motes has at the same time been cleared of the microrganisms that cause disease1 putrefaction1 and fermentation2 and that germ-free flesh or liquids may be indefinitely exposed in such air without fermentation or decay4 ,how ,dust ,motes ,are ,counted4 ,many of the particles are too small to be seen by the highest powers of the microscope1 yet ,aitken1 by a most ingenious method of making them centers of condensation--that is1 making them the nuclei of small raindrops--was able to count the number in a given volume of air4 ,when ordinary air is saturated and then cooled the cloud formed is so dense that it is impossible to count the tiny droplets that form the cloud4 ,but we can make the number of dust particles 7and therefore the number of visible points of condensation7 in a given volume of air as small as we wish by mixing a little dusty air with a large amount of dustless air1 and we can allow the particles to fall on a bright surface and can count them by means of a lens or microscope4 ,by simply allowing for the proportion of the dustless to the dusty air1 and making a corresponding allowance for the dilution1 we calculate the number of particles4 ,dust ,motes and ,illumination of the ,atmosphere4 ,one of the most important functions of dust motes is the diffusion or scattering of sunlight4 ,what a different world this would be without these tiny inanimate friends of man6 ,if there were no dust in suspension in the air1 nothing would be visible except what received direct light1 or light reflected from some illuminated surface1 and the air occupying space between illuminated objects would be practically dark4 ,if the observer be in a room with a powerful electric light he would see the walls and the objects in the room1 but if the air were free of dust motes1 he would find that the space between him and the walls and between the various objects would be as inky black as is the space between the twinkling stars on a clear night4 ,illustration3 ,,fig4 #b4--,showing light from lamp a passing into dust-free air at b1 and passing out at c without illuminating the interior4 ,figure #b is a cubical box1 with a glass front4 ,if a glutinous substance be spread over the bottom and the box allowed to remain quiescent for from five to seven days the dust motes will slowly settle down and attach themselves to the bottom4 ,the air then will be what is called 8optically pure40 ,now1 if it be taken into a dark room and an inclosed lamp at a be allowed to send a beam of light into the window at b and out at c1 it will be found that the interior remains dark no matter how powerful the light from the lamp4 ,the light is seen to enter and to leave but where it encounters the dust-free air there is nothing to scatter the light rays and they remain invisible to the eye4 ,dust ,motes ,prolong ,twilight4 ,the bending or refraction of light as the sun's rays pass obliquely through the air at sunrise and at sunset displaces the apparent position of the sun1 elevating it by an amount about equal to its own apparent diameter1 so that one may see it and receive its light when geometrically it is entirely below the horizon4 ,a little later in the evening and its rays fall upon the upper air too obliquely to be bent down to the earth by refraction2 but darkness does not yet ensue1 for the rays are scattered by the dust motes and possibly by the molecules of the gases and sent downward from particle to particle1 resulting in a soft shimmering light that almost imperceptibly fades away1 and which in higher latitudes may last for hours4 ,,chapter ,v ,,light1 ,,heat1 ,,and ,,temperature ,,more ,,wonderful ,,than ,,any ,,fiction ,,are ,,the ,,fact ,,of ,,invisible ,,light1 ,,and ,,the ,,difference ,,between ,,heat ,,and ,,temperature ,the heat that escapes from the earth's interior is minute in comparison to that received from the sun1 which is the main source of the earth's supply4 ,heat is manifested by the motions of the molecules of matter1 whether solid1 liquid1 or gaseous4 ,it is transmitted through space in some mysterious manner1 for space is practically void of an atmosphere4 ,one cannot conceive of motion taking place in a void1 for there is nothing to move4 ,therefore it is assumed that interstellar space must be filled with a transmitting medium2 to this the name of ether has been given4 ,nothing is known of its structure1 but it is believed that it penetrates all bodies and fills the space between their molecules4 ,how ,heat and ,light ,reach the ,earth4 ,the heat of the sun is some forty-six thousand times as intense as is the heat of the earth4 ,the violent agitations of the molecules of the sun's hot atmosphere impart vibrations to the ether of space1 which decrease in effectiveness inversely as the square of the distance2 that is to say1 that if the earth were twice as far from the sun as it is1 the intensity of the solar rays would be one fourth of what they are now4 ,these vibrations are called solar energy4 ,they pass through space without perceptibly warming or lighting it4 ,when they encounter the molecules of the earth's atmosphere1 and the dust and cloud in suspension in the air1 or impinge upon the solid matter of the earth1 they are transmuted back into molecular agitations1 and manifest themselves in a multitude of forms1 such as heat1 light1 chemical rays1 electricity1 etc4 ,the ,difference between ,heat and ,temperature4 ,the agitation of the molecules of a substance set up by the absorption of heat is indicated by temperature1 which gives no measure of the quantity of heat absorbed1 the quantity varying widely for different kinds of matter4 ,the amount of heat necessary to raise one pound of water #a ,f4 is the heat unit generally employed in commerce2 but in scientific research the amount necessary to raise one gram of water #a ,centigrade is the unit of heat best adapted to use4 ,it is called the gram-calorie4 ,let us take a glass filled with boiling water4 ,you see the glass and the water because they reflect to the eye light waves received from some source1--possibly the sunlight that is diffused by the dust motes of the air into the room through the window4 ,but the glass and the water radiate other waves to which the eye is not sensible2 these invisible long heat waves may be felt by the nerves of the hand4 ,they warm all matter upon which they fall by adding to the agitation of the molecules of which it is composed2 but they do not warm all matter equally4 ,the waves that reach dark bodies are broken up2 that is to say1 absorbed4 ,their energy is transmuted into sensible heat1 and in the place of the waves we have molecular vibrations in the matter1 which are made manifest by a rise in its temperature4 ,dark rough surfaces more completely absorb the waves and therefore rise to a higher temperature than the same surfaces when smooth4 ,when the waves encounter bright and highly polished surfaces the effect is quite different2 then most of them are reflected away and therefore warm the matter but little4 ,these reflected waves are not broken up1 but on the contrary start off in some new direction1 possibly falling upon and warming some matter more receptive to their influence4 ,the higher the polish the more completely are the waves reflected4 ,difference between ,light ,waves1 ,heat ,waves1 and ,sound ,waves4 ,the light and the heat waves of the ether are infinitesimal ripples as compared to the backward and forward pulsations that constitute the sound waves of the air4 ,within a space of one inch there are sixty-six thousand of the violet waves of light1 which are the shortest etheric vibrations to which the human eye responds1 and over thirty thousand of the red waves1 the longest that affect the eye2 while the sound waves of the air vary from about one foot for the shrill notes of the human voice to four feet for the middle ,c of the pianoforte4 ,a shrill whistle produces waves of about one half inch4 ,there are twenty-two thousand of certain heat waves to the inch1 and these1 like some of the light waves of the ether1 are invisible4 ,there is also a vast difference between the velocity of vibration of the air waves and those of the ether4 ,the human ear is sensitive to sound waves of somewhere between twenty-nine per second to thirty-eight thousand per second2 while the eye responds to light waves of from five hundred million to one billion per second4 ,some ears are better adjusted to the low vibrations and some to the high1 and the ears of no one hear any but a small part of the melody of a great symphony4 ,tyndall could hear the sharp chirp of thousands of insects that were inaudible to his guide as the two climbed the ,alps1 but the guide's ears responded to the long1 slow waves that came from the dull tread of the donkey's hoofs farther up the mountain1 which waves the scientist was unable to hear4 ,likewise some eyes are able to penetrate far into the violet1 or the red1 or both1 and some are unable to distinguish between certain colors4 ,chemical ,rays of ,light4 ,the chemical or photographic rays have still shorter waves than the violet4 ,they produce special physiological effects in vegetable and animal tissues1 and1 acting upon particular kinds of matter1 they cause fluorescence1 which is the property possessed by some bodies of giving off1 when illuminated1 light of a color different from their own and from that of the light that illuminates them4 ,these chemical rays are sometimes called ultra-violet rays4 ,invisible ,light4 ,from a reading of the immediately preceding paragraphs one may be prepared for the startling statement that there is such a thing as invisible light4 ,vibrations of the ether that move slower than those that give to the eye the sensation of red are invisible1 as are those that move faster than the violet rays1 and it is certain that neither the eye of man nor of animal ever will see but a small part of the beauty of a landscape or the delicate coloring of a flower4 ,the eye only takes in and renders sensible to the brain the red1 orange1 yellow1 green1 blue1 indigo1 violet1 and their various tints1 but the delicate instruments of science reveal many other colors4 ,one sees as through a glass darkly1 for the gentle signals that might reveal the beauties of ,paradise fall upon the eye unheeded4 ,a keener vision and a more complete appreciation of the beauties and the wonders of the universe await one on the other side of the gauzy veil of immortality4 ,the finger tips of the outstretched arms may span the river of life and the ethereal breath of loved ones may be caressing one's cheek4 ,the music of the spheres is not a myth2 the lily or the rose as it opens its petals to receive the benediction of the morning sun may give forth a veritable pan of joy4 ,a rose bush may be a grander symphony than anything that ,beethoven ever wrote4 ,what to us is the invisible light may be the illumination that guides the sweep of the angels' wings4 ,how ,heat ,moves through or ,is ,transmitted by ,matter4 ,heat passes by contact from the warmer to the colder molecules of a body4 ,this action is called conduction4 ,when one end of a bar of iron is held in a fire1 the end away from the fire soon becomes too hot to hold in the hand1 because heat is rapidly transferred from the hot portion of the bar to the cooler portion by conduction1 showing that iron is a good conductor4 ,on the other hand1 the end of a stick of wood can be held in the fire until it is completely consumed without the other end becoming too warm to hold1 indicating that wood is a poor conductor4 ,metals are the best conductors1 silver leading the list1 with copper second4 ,snow and ice and fibrous and porous substances are poor conductors1 and are called insulators4 ,air and water are also poor conductors4 ,the fur of animals and the feathers of birds protect against the rapid loss of heat because they contain numerous interstices filled with air1 a poor conductor4 ,heat is lost by radiation when the molecules of matter set up vibration in the ether4 ,the atmosphere itself performs this function on a large scale when the sky is cloudless1 so that radiated heat is not absorbed by the cloud covering and its loss into space restricted4 ,when air or water is not evenly or homogeneously heated a circulation is set up in which the colder part settles down and the warmer rises4 ,this is called convection4 ,the air that is heated by contact with a stove rises and passes along the ceiling to the colder parts of the room1 gradually parting with its heat until it is no warmer than the air next adjacent to it1 and slowly settling to the floor as the cold air beneath it moves toward the stove1 is warmed and sent aloft1 the first air finally making a complete circuit and returning to the stove again4 ,in this way the heat is distributed by convection throughout the whole room4 ,when one part of the earth's surface becomes hotter than another a similar action takes place on a large scale4 ,the region of greater temperature warms the air above it1 and the surrounding denser air flows in along the surface1 forcing the lighter air to rise1 when it in turn is similarly warmed and driven up4 ,the clear waters of lakes and rivers and of the ocean permit the passage of heat waves to a considerable depth before they are completely absorbed4 ,on a cold day in winter1 when the sun is shining brightly1 a room with spacious windows may become as warm as though heated by a furnace1 simply by the capacity of the glass in the windows to transmit the heat waves of the sun without considerable absorption1 and at the same time prevent the escape of the longer heat waves that are radiated from the interior walls of the room4 ,this capacity of matter to transmit heat waves without absorption is called diathermancy4 ,the clear atmosphere is an exceedingly good transmitter1 and rock salt is one of the best of all solids4 ,the capacity of a body to transmit light without absorbing it and becoming luminous is called transparency4 ,air freed of dust motes is almost perfectly transparent4 ,in this state it is said to be optically pure4 ,but the ordinary air of nature1 with its moisture and dust1 absorbs most of the blue wave lengths and also many of the longer ones of the other colors of the spectrum4 ,the capacity of a body for heat is called its specific heat4 ,with but few exceptions the specific heats of liquids are much greater than those of solids or gases4 ,it requires ten times the quantity of heat to raise a pound of water one degree that it does a pound of iron4 ,ice has the greatest specific heat of any of the solids1 except paraffin and wood4 ,when a solid is melted or a liquid vaporized a large amount of heat becomes latent1 insensible to the touch2 it disappears as heat4 ,this is one of the most wonderful of the phenomena of nature4 ,it matters not how long the time may be1 an hour1 a day1 a year1 or a thousand years after the solid is melted or the liquid turned to vapor1 so soon as the vapor returns to the liquid state or the liquid to a solid condition1 the latent heat becomes sensible in exactly the same degree in which it previously existed4 ,let us illustrate with a pound of ice at zero ,f4 ,sixteen heat units1 or sixteen times as much heat as is required to raise one pound of water one degree1 must be absorbed by this pound of ice to raise its temperature to the melting point 7#cb72 and then one hundred forty-four more heat units must be absorbed to so far overcome the tendency of the molecules to adhere1 or remain together1 that the molecules may roll the one about the other in the liquid form1 but with this important difference3 the one hundred forty-four units become latent and do not1 therefore1 cause any increase in temperature1 as the sixteen heat units did in raising the temperature of the ice4 ,the large quantity of heat required to change the ice to a liquid is called the latent heat of melting4 ,any further addition of heat after the melting is complete causes an increase in temperature1 and one hundred eighty heat units will raise it to the boiling point4 ,water boils at #bab at sea level and normal pressure2 that is to say1 at that temperature the agitation of the molecules of water is so great as to overcome both cohesion and the weight with which the air presses down upon them1 and cause them to fly away in the form of steam1 which is invisible when confined inside a boiler4 ,but the entire pound of water is not instantly changed to the gaseous condition1 for with the sending off of the first few molecules some heat is rendered latent1 and more must be supplied or the boiling ceases2 in fact the enormous quantity of #ifd4fb heat units must be supplied to entirely change the pound of water to steam1 but at no time does the temperature rise above #bab4 ,as in the former case of changing the solid to a liquid1 a large amount of heat becomes latent2 in this case it is called the latent heat of vaporization4 ,now carefully fix in the mind that a liquid does not need to be raised to its boiling point before vaporization begins1 for it operates at all temperatures1 even after the liquid is frozen1 but much more rapidly from the liquid4 ,if one wishes to test this3 weigh a piece of ice during very cold weather4 ,then leave it out in a temperature that is below freezing for several days1 and on weighing again it will be found that the ice has lost weight4 ,all evaporation produces a cooling effect because of the heat that is rendered latent in the process of changing the liquid or the solid to a gaseous form4 ,the drier the air the greater is the cooling effected by keeping the surface wetted1 and the cooling is accelerated by placing the wet object where there is a free circulation of air4 ,a wooden water bucket that has been soaked for a day or two so that every part of the wood is saturated with water1 will1 if kept closed1 keep water all day in the open field practically as cool as when it left the deep well1 and often cooler4 ,not enough use is made of cooling by evaporation by those who have not ice in the summer4 ,inexpensive and fairly effective refrigerators may be made1 by any mechanic1 of lattice-work sides covered with any thick fabric and kept moist1 which would keep milk1 butter1 fruit1 vegetables1 and cooked meats in good condition if placed in a hallway with a good circulation of air1 or in any shady place with good ventilation4 ,most solids expand with gain in temperature and therefore possess greater volume in the liquid form than in the solid1 and the temperature of their melting points rises as they are subjected to increasing pressure4 ,the law reverses when applied to ice1 which contracts in melting4 ,to few is it known that a skater on ice really rides upon water molecules1 for the sharp edge of the skate1 when applied to the ice under the weight of one's body1 is lubricated by the slight melting of the ice in immediate contact with the skate1 the molecules of water returning to the form of ice as soon as the skater passes and the pressure is relieved4 ,the strange phenomenon may be witnessed by passing a wire through a block of ice without severing it into two pieces1 by attaching heavy weights to the two ends of the wire and suspending it across the ice1 the ice slowly melting as the result of the pressure applied by the underside of the wire and freezing molecules closing the space on top of the wire4 ,by this process do we account for the moving of glaciers down tortuous valleys as though they were liquids4 ,altitude ,measured by ,change in ,boiling ,point of ,water4 ,the boiling point of water at sea level and ordinary air pressure is #bab4 ,if the pressure of the atmosphere were increased to about thirty pounds1 instead of about fifteen to the square inch it would be necessary to raise water to #bej before boiling would begin4 ,the changes of air pressure due to the passage of the severe storms of winter may cause the boiling point of water to vary from #bjg to #bae4 ,this knowledge may be useful in measuring the heights of mountains1 although the method does not give close results4 ,the decrease of pressure with altitude lowers the boiling point1 the amount being approximately one degree for each #eee feet of ascent4 ,the best results may be secured by having a person at the base of the mountain1 where the elevation above sea level is known1 determine the boiling point at the same time that a person on the mountain top does4 ,the thermometers should be read closely to the fraction of a degree4 ,with the barometer at its normal height of thirty inches1 air at #fj will instantly rise to the phenomenal temperature of #age4ej if it be confined and its pressure doubled1 and it will diminish to one half of its former volume4 ,but if its pressure be diminished one half1 its volume will expand to double its original size and its temperature will fall from #fj to #b4d4 ,from these facts the reader would naturally expect to find low pressure of the atmosphere accompanying cold waves and high pressure to be coincident with warm conditions1 which is exactly the reverse of what actually occurs in the free air of nature4 ,this apparent contradiction will be made plain in the treatment of cold waves1 page #abd4 ,a temperature of -#dei on the ,fahrenheit scale and -#bgc4a on the ,centigrade represents what is called absolute zero4 ,it is supposed to be the temperature at which there is no motion of the molecules of matter4 ,bodies or planets without atmospheres have temperatures approaching absolute zero1 for there is no protecting envelope to absorb heat or to prevent the instant radiation into space of that which impinges upon the body4 ,our moon is an illustration1 and notwithstanding the fierce beating upon its surface of the solar energy it remains incased in the intense cold of space4 ,the thermometer is the instrument that measures temperature4 ,it was not until eighty-seven years after ,columbus discovered ,america that ,galileo discovered the principle of the thermometer4 ,this first instrument was crude4 ,it consisted of a glass bulb1 containing air1 terminating below in a long glass tube1 which dipped into a vessel containing colored water4 ,when the temperature fell the contraction of the air in the bulb caused the water to rise in the tube1 and when the temperature rose the expansion of the air forced the water to a lower level4 ,galileo also invented the alcohol thermometer in #afaa1 but the determination of the zero and some fixed point above it1 by which to graduate the scale1 took years to evolve4 ,the modern alcohol and mercury thermometers consist of a bulb filled with the liquid1 and a tube partly filled1 the upper part being a tolerably complete vacuum1 allowing the liquid freedom of movement up and down the tube4 ,when a tube is broken one is surprised to see that the diameter of the bore is less than that of the smallest fuzzy hair from the back of the hand4 ,the size of the column of mercury is magnified by the action of light passing through the glass of the tube4 ,temperatures are usually taken in the shade4 ,the instrument should be free from all bodies that could conduct heat to it1 and it should have free circulation of air about it4 ,in a complete meteorological station automatically recording instruments1 too complicated for the use of the layman1 record for each moment of time the temperature of the air and its pressure1 the periods of sunshine1 the duration and the amount of rainfall1 and the direction and velocity of the wind4 ,,chapter ,,vi ,,the ,,advantage ,,of ,,taking ,,weather ,,observations ,,and ,,applying ,,them ,,to ,,one',s ,,personal ,,needs ,,forecasts ,,made ,,from ,,the ,,aneroid ,,barometer--,,colds ,,prevented ,,by ,,moistening ,,air ,,in ,,living ,,rooms--,a ,,criminal ,,hanged ,,and ,,an ,,innocent ,,man ,,freed ,,by ,,weather ,,records ,observations from ,kites4 ,it is strange that the ,chinese1 who have been flying kites many thousand years1 should not have made improvements in the primitive construction of these devices4 ,it remained for ,wendham1 in #ahff1 to perceive the advantage of superimposing two or more planes1 one above the other1 for the purpose of securing a larger area of sustaining surface4 ,after examining ,figure #c almost any one can build an efficient kite4 ,heights of two to three thousand feet may be reached by using cable-laid twine ,no4 #bd1 but in order to gain great altitudes pianoforte wire must be used4 ,soft pine is the best and most available material4 ,spruce is stronger1 but more difficult to secure4 ,the sticks should be straight-grained4 ,the cloth may be silk or the stronger and finer grades of cotton4 ,it should be torn1 not cut4 ,the ends will then be true and square with the fiber of the cloth4 ,kites are used not only to secure weather observations1 but they have been used to draw sleds in the ,arctic region1 and to draw wagons and boats4 ,by adjusting the points at which the pulling cords are attached to the boat an ingenious sailor is able to proceed nearly at right angles to the direction of the wind4 ,illustration3 ,,fig4 #c4--,,standard ,,weather ,,bureau ,,kite4 ,when it is known that a box kite having only sixty square feet of sustaining surface1 flying at a considerable height1 may lift a person of ordinary size1 one is impressed with the idea that vessels of commerce might employ kites of large dimensions to increase the speed of sailing ships4 ,the kites would fly in a stratum whose velocity is not restricted by friction with the surface of the water4 ,to launch a kite3 run out about one hundred and fifty feet of the cord or wire while the kite is held by an assistant1 who should give the kite a toss upward in the direction in which it must go4 ,it is important that it be cast off directly in line with the wind4 ,if the wind is light it may be necessary to run a short distance with a long line out in order to effect a launching4 ,voluntary ,weather ,observers4 ,there are more than three thousand voluntary or coperating observers in the ,u4 ,s4 ,weather ,bureau4 ,they receive no compensation other than the publications of the ,bureau4 ,they are required to read their instruments but once each day1 as maximum and minimum thermometers record the highest and the lowest temperatures since they were last read and set4 ,about sunset is the most satisfactory time for making the readings1 since the thermometers will then show both the extremes for the past twenty-four hours4 ,as a rule but one voluntary observer is accepted for a county4 ,they are furnished without charge with maximum and minimum thermometers1 instrument shelters and rain gauges1 but not with wind vanes1 anemometers for recording direction and velocity of wind1 or barometers4 ,but those who desire to become expert in forecasting the weather1 as all may who study the chapter on forecasting1 should equip themselves with an aneroid barometer1 so that they may note the changes in the pressure of the air4 ,illustration3 ,,fig4 #e4--;,comparison of the ,thermometer ,scales4 ,,comparison ,,of ,,thermometer ,,scales ,a little study of the accompanying information and diagram will enable any one to form a clear idea of the various thermometer scales and to convert temperatures from one scale to another4 ,table of fixed points4 ---------------------------------------- -------------------- ,scale4 ,temperature of ,temperature of ,no4 of degrees melting ice4 boiling water4 between melting ice and boiling water4 ---------------------------------------- -------------------- ,centigrade #j #ajj #ajj ,reaumur #j #hj #hj ,fahrenheit #cb #bab #ahj ---------------------------------------- -------------------- ,only ,fahrenheit and ,centigrade scales are in general use1 and the accompanying plate is designed to enable observers to convert temperature readings from one scale to the other without resorting to a mathematical formula4 ,for accurate and precise reductions between the different scales the following rules should be used3 #a4 ,to convert ,fahrenheit to ,centigrade3 ,subtract #cb and multiply by five ninths4 #b4 ,to convert ,centigrade to ,fahrenheit3 ,multiply by nine fifths and add #cb4 #c4 ,to convert ,fahrenheit to ,reaumur3 ,subtract #cb and multiply by four ninths4 #d4 ,to convert ,reaumur to ,fahrenheit3 ,multiply by nine fourths and add #cb4 #e4 ,to convert ,centigrade to ,reaumur3 ,multiply by four fifths4 #f4 ,to convert ,reaumur to ,centigrade3 ,multiply by five fourths4 ,an instrument shelter 7,figure #d7 is employed to screen off the direct and reflected sunshine1 and to keep the thermometers dry4 ,this shelter is a box with louvered sides1 constructed in such form that there is a free circulation of air through it4 ,it should be exposed in an open space as far away from buildings as may be convenient1 or on a housetop1 and be as free from shadows as possible4 ,if such position cannot be secured1 then place it on the north side of a building4 ,illustration3 ,,fig4 #f4--;,dry and ,wet ,bulb ,thermometers4 ,comparison of ,centigrade and ,fahrenheit4 ,only ,fahrenheit and ,centigrade are in general use4 ,figure #e is designed to enable observers to convert temperature readings from one scale to the other without resorting to a mathematical formula4 ,for precise reductions the following rules apply3 ,to convert ,fahrenheit to ,centigrade3 ,subtract #cb and multiply by five ninths4 ,to convert ,centigrade to ,fahrenheit3 ,multiply by nine fifths and add #cb4 ,humidity ,affects ,health and ,complexion4 ,the importance to health of maintaining a proper humidity in living quarters during the winter months and during all months in the arid and semi-arid regions of the ,west is not fully appreciated4 ,each habitation should be supplied with one to several hygrometers 7,fig4 #f71 and frequent readings should be taken of the dry and the wet bulb thermometers so as to be familiar with the conditions under which one is living4 ,,relative ,,humidity ,,tables ,temperature ,readings in ,degrees ,fahrenheit4 ,relative ,humidity ,readings in ,per ,cent4 ,barometric ,pressure #bi4j inches4 7,part #a of #g7 ,,difference ,,in ,,degrees ,,fahrenheit ,,between ,,wet ,,readings ,,and ,,dry ,,bulb ,,thermometers4 ,,of ,,dry ,,bulb ---------------------------------------- ---- ,,thermometer #a #b #c #d #e #f #g #h #i #aj #aa ---------------------------------------- ---------------- #bj #he #gj #ef #db #bh #ad #ba #hf #ga #eg #dd #cj #ag #c #bb #hf #gb #ei #de #cb #ai #g #bc #hg #gc #fj #dg #cd #bb #aj #bd #hg #gd #fa #di #cf #bd #ab #j #be #hg #ge #fc #ej #ch #bg #ae #d #bf #hh #ge #fd #eb #dj #bi #ah #g #bg #hh #gf #fe #ec #db #ca #bj #i #bh #hh #gg #ff #ee #dd #cc #bc #ab #b #bi #hi #gh #fg #ef #de #ce #be #ae #e #cj #hi #gh #fh #eg #dg #cg #bg #ag #h #ca #hi #gi #fi #eh #di #ci #bi #bj #aj #a #cb #ij #gi #fi #fj #ej #da #ca #bb #ac #d #cc #ij #hj #ga #fa #eb #db #cc #bd #af #g #cd #ij #ha #gb #fb #ec #dd #ce #bg #ah #i #a #ce #ia #hb #gc #fd #ee #df #cg #bi #bj #ab #d #cf #ia #hb #gc #fe #ef #dh #ci #ca #bc #ad #f #cg #ia #hc #gd #ff #eh #di #da #cc #be #ag #i #ch #ia #hc #ge #fg #ei #ea #dc #ce #bg #ai #ab #ci #ib #hd #gf #fh #fj #eb #dd #cg #bi #ba #ad #dj #ib #hd #gf #fh #fa #ec #df #ch #ca #bc #af #da #ib #hd #gg #fi #fb #ed #dg #dj #cc #bf #ah #db #ib #he #gg #gj #fb #ee #dh #da #cd #bh #ba #dc #ib #he #gh #gj #fc #ef #di #dc #cf #bi #bc #dd #ic #he #gh #ga #fd #eg #ea #dd #cg #ca #bd #de #ic #hf #gi #ga #fe #eh #eb #de #ci #cc #bf #df #ic #hf #gi #gb #fe #ei #ec #df #dj #cd #bh #dg #ic #hf #gi #gc #ff #fj #ed #dg #da #ce #bi #dh #ic #hg #hj #gc #fg #fj #ed #dh #db #cf #ca #di #ic #hg #hj #gd #fg #fa #ee #di #dc #cg #cb ---------------------------------------- ---------------- 7,part #b of #g7 ,,difference ,,in ,,degrees ,,fahrenheit ,,between ,,wet ,,readings ,,and ,,dry ,,bulb ,,thermometers4 ,,of ,,dry ,,bulb ---------------------------------------- ,,thermometer #ab #ac #ad #ae #af #ag #ah #ai #bj #ba ---------------------------------------- ------------ #bj #ba #bb #bc #bd #be #bf #bg #bh #bi #cj #ca #cb #cc #cd #ce #cf #cg #a #ch #d #ci #g #dj #i #b #da #aa #e #db #ad #g #j #dc #af #i #c #dd #ah #ab #e #de #bj #ad #h #b #df #bb #af #aj #d #dg #bc #ag #ab #f #a #dh #be #ai #ad #h #c #di #bf #ba #ae #aj #e ---------------------------------------- ------------ ,,relative ,,humidity ,,tables--,continued ,temperature ,readings in ,degrees ,fahrenheit4 ,relative ,humidity ,readings in ,per ,cent4 ,barometric ,pressure #bi4j inches4 7,part #c of #g7 ,,difference ,,in ,,degrees ,,fahrenheit ,,between ,,wet ,,readings ,,and ,,dry ,,bulb ,,thermometers4 ,,of ,,dry ,,bulb ---------------------------------------- ---- ,,thermometer #a #b #c #d #e #f #g #h #i #aj #aa ---------------------------------------- ---------------- #ej #ic #hg #ha #gd #fh #fb #ef #ej #dd #ci #cc #ea #id #hg #ha #ge #fi #fc #eg #ea #de #dj #ce #eb #id #hh #ha #ge #fi #fc #eh #eb #df #da #cf #ec #id #hh #hb #ge #gj #fd #eh #ec #dg #db #cg #ed #id #hh #hb #gf #gj #fe #ei #ed #dh #dc #ch #ee #id #hh #hb #gf #ga #fe #fj #ee #di #dd #ci #ef #id #hh #hb #gg #ga #ff #fa #ee #ej #de #dj #eg #id #hh #hc #gg #gb #ff #fa #ef #ea #df #da #eh #id #hi #hc #gg #gb #fg #fb #eg #eb #dg #db #ei #id #hi #hc #gh #gc #fh #fc #eh #ec #dh #dc #fj #id #hi #hd #gh #gc #fh #fc #eh #ec #di #dd #fa #id #hi #hd #gi #gd #fh #fd #ei #ed #ej #de #fb #id #hi #hd #gi #gd #fi #fd #fj #ee #ej #df #fc #ie #ij #hd #gi #gd #gj #fe #fj #ef #ea #dg #fd #ie #ij #he #gi #ge #gj #ff #fa #ef #eb #dh #fe #ie #ij #he #hj #ge #gj #ff #fb #eg #ec #dh #ff #ie #ij #he #hj #gf #ga #ff #fb #eh #ec #di #fg #ie #ij #he #hj #gf #ga #fg #fb #eh #ed #ej #fh #ie #ij #he #ha #gf #gb #fg #fc #ei #ee #ea #fi #ie #ij #hf #ha #gg #gb #fh #fd #ei #ee #ea #gj #ie #ij #hf #ha #gg #gb #fh #fd #fj #ef #eb #ga #ie #ij #hf #hb #gg #gc #fi #fd #fj #ef #ec #gb #ie #ia #hf #hb #gh #gc #fi #fe #fa #eg #ec #gc #ie #ia #hf #hb #gh #gc #fi #fe #fa #eh #ed #gd #ie #ia #hf #hb #gh #gd #gj #ff #fb #eh #ed #ge #if #ia #hg #hb #gh #gd #gj #ff #fc #ei #ee #gf #if #ia #hg #hc #gh #gd #gj #fg #fc #ei #ee #gg #if #ia #hg #hc #gi #ge #ga #fg #fc #fj #ef #gh #if #ia #hg #hc #gi #ge #ga #fg #fd #fj #eg #gi #if #ia #hg #hc #gi #ge #ga #fh #fd #fj #eg ---------------------------------------- ---------------- 7,part #d of #g7 ,,difference ,,in ,,degrees ,,fahrenheit ,,between ,,wet ,,readings ,,and ,,dry ,,bulb ,,thermometers4 ,,of ,,dry ,,bulb ---------------------------------------- ,,thermometer #ab #ac #ad #ae #af #ag #ah #ai #bj #ba ---------------------------------------- ------------ #ej #bh #bb #ag #ab #g #b #ea #bi #bd #ai #ad #i #d #eb #cj #be #bj #ae #aj #f #j #ec #cb #bg #bb #ag #ab #g #c #ed #cc #bh #bc #ah #ad #i #e #j #ee #cd #bi #be #bj #ae #aa #f #b #ef #ce #ca #bf #ba #ag #ab #h #d #eg #cf #cb #bg #bc #ah #ad #aj #e #a #eh #ch #cc #bh #bd #bj #ae #aa #g #c #ei #ci #cd #cj #be #ba #ag #ac #i #e #a #fj #dj #ce #ca #bg #bb #ah #ad #aj #f #b #fa #dj #cf #cb #bh #bd #bj #af #ab #h #d #fb #da #cg #cc #bi #be #ba #ag #ac #i #f #fc #db #ch #cd #cj #bf #bb #ah #ad #aa #g #fd #dc #ci #ce #ca #bg #bc #bj #af #ab #i #fe #dd #dj #cf #cb #bh #be #ba #ag #ac #aj #ff #de #da #cg #cc #bi #bf #bb #ah #ae #aa #fg #df #db #ch #cd #cj #bg #bc #bj #af #ac #fh #dg #dc #ci #ce #ca #bh #bd #ba #ag #ad #fi #dg #dd #dj #cf #cb #bi #be #bb #ai #ae #gj #dh #dd #dj #cg #cc #cj #bf #bc #bj #ag #ga #di #de #da #ch #cd #ca #bg #bd #ba #ah #gb #di #df #db #ci #ce #cb #bh #be #bb #ai #gc #ej #df #dc #dj #cf #cc #bi #bf #bc #bj #gd #ea #dg #dd #dj #cg #cd #cj #bg #bd #ba #ge #ea #dh #dd #da #ch #cd #ca #bh #be #bb #gf #eb #dh #de #db #ch #ce #cb #bi #bf #bc #gg #eb #di #df #db #ci #cf #cc #cj #bg #bd #gh #ec #ej #df #dc #dj #cg #cd #ca #bh #be #gi #ed #ej #dg #dd #da #cg #cd #ca #bi #bf ---------------------------------------- ------------ ,,relative ,,humidity ,,tables--,continued ,temperature ,readings in ,degrees ,fahrenheit4 ,relative ,humidity ,readings in ,per ,cent4 ,barometric ,pressure #bi4j inches4 7,part #e of #g7 ,,difference ,,in ,,degrees ,,fahrenheit ,,between ,,wet ,,readings ,,and ,,dry ,,bulb ,,thermometers4 ,,of ,,dry ,,bulb ---------------------------------------- ---- ,,thermometer #a #b #c #d #e #f #g #h #i #aj #aa ---------------------------------------- ---------------- #hj #if #ia #hg #hc #gi #gf #gb #fh #fd #fa #eg #hb #if #ib #hh #hd #hj #gf #gb #fi #fe #fb #eh #hd #if #ib #hh #hd #hj #gg #gc #gj #ff #fc #ei #hf #if #ib #hh #he #ha #gg #gd #gj #fg #fc #fj #hh #if #ib #hh #he #ha #gh #gd #ga #fg #fd #fa #ij #if #ib #hi #he #ha #gh #ge #ga #fh #fe #fb #ib #if #ib #hi #he #hb #gh #ge #gb #fi #fe #fb #id #if #ic #hi #hf #hb #gi #ge #gb #fi #ff #fc #if #if #ic #hi #hf #hb #gi #gf #gc #gj #fg #fd #ih #if #ic #hi #hf #hc #gi #gf #gc #gj #fg #fd #ajj #if #ic #ij #hf #hc #hj #gg #gd #ga #fh #fe #ajb #if #ic #ij #hf #hc #hj #gg #gd #ga #fh #fe #ajd #ig #ic #ij #hg #hd #hj #gg #gd #gb #fi #ff #ajf #ig #ic #ij #hg #hd #ha #gh #ge #gb #fi #ff #ajh #ig #ic #ij #hg #hd #ha #gh #ge #gb #gj #fg #aaj #ig #ie #ij #hg #hd #ha #gh #gf #gc #gj #fg #aab #ig #id #ij #hg #hd #hb #gi #gf #gc #gj #fh #aad #ig #id #ia #hh #he #hb #gi #gf #gd #ga #fh #aaf #ig #id #ia #hh #he #hb #gi #gg #gd #ga #fi #aah #ig #id #ia #hh #he #hb #gi #gg #gd #gb #fi #abj #ig #id #ia #hh #he #hb #hj #gg #gd #gb #fi #abb #ig #id #ia #hh #he #hc #hj #gg #ge #gb #gj #abd #ig #id #ia #hh #hf #hc #hj #gh #ge #gc #gj #abf #ig #id #ia #hi #hf #hc #ha #gh #ge #gc #ga #abh #ig #id #ia #hi #hf #hc #ha #gh #gf #gc #ga #acj #ig #id #ib #hi #hf #hd #ha #gh #gf #gd #ga #acb #ig #id #ib #hi #hf #hd #ha #gi #gf #gd #gb #acd #ig #id #ib #hi #hf #hd #ha #gi #gf #gd #gb #acf #ig #id #ib #hi #hg #hd #hb #gi #gg #gd #gb #ach #ig #id #ib #hi #hg #hd #hb #gi #gg #ge #gb #adj #ig #ie #ib #hi #hg #hd #hb #hj #gg #ge #gc ---------------------------------------- ---------------- 7,part #f of #g7 ,,difference ,,in ,,degrees ,,fahrenheit ,,between ,,wet ,,readings ,,and ,,dry ,,bulb ,,thermometers4 ,,of ,,dry ,,bulb ---------------------------------------- ---- ,,thermometer #ab #ac #ad #ae #af #ag #ah #ai #bj #ba #bb ---------------------------------------- ---------------- #hj #ed #ea #dg #dd #da #ch #ce #cb #bi #bg #bd #hb #ee #eb #di #df #dc #dj #cg #cd #ca #bh #be #hd #ef #ec #ej #dg #dd #da #ch #ce #cb #cj #bg #hf #eg #ed #ea #dh #de #db #ci #cg #cd #ca #bi #hh #eh #ee #eb #di #df #dc #da #ch #ce #cc #cj #ij #ei #ef #ec #ej #dg #dd #db #ci #cg #cd #cb #ib #ei #eg #ed #ea #dh #de #dc #dj #ch #ce #cc #id #fj #eg #ed #eb #di #df #dd #da #ci #cf #cd #if #fa #eh #ee #ec #ej #dg #de #db #dj #cg #ce #ih #fa #ei #ef #ec #ea #dh #df #dc #da #ci #cf #ajj #fb #ei #eg #ed #eb #di #dg #dd #db #dj #cg #ajb #fc #fj #eg #ee #eb #ej #dg #de #dc #da #ch #ajd #fc #fa #eh #ef #ec #ea #dh #df #dd #da #ci #ajf #fd #fa #ei #ef #ed #ea #di #dg #de #db #dj #ajh #fd #fb #ei #eg #ed #eb #ej #dg #de #dc #da #aaj #fe #fb #fj #eg #ee #ec #ej #dh #df #dd #db #aab #fe #fc #fj #eh #ef #ec #ea #di #dg #de #dc #aad #ff #fc #fa #ei #ef #ed #eb #ej #dh #de #dc #aaf #ff #fd #fa #ei #eg #ee #eb #ej #dh #df #dd #aah #fg #fd #fb #fj #eg #ee #ec #ea #di #dg #de #abj #fg #fe #fb #fj #eh #ef #ed #ea #di #dg #df #abb #fg #fe #fc #fa #eh #ef #ed #eb #ej #dh #df #abd #fh #fe #fc #fa #ei #eg #ee #ec #ea #di #dg #abf #fh #ff #fd #fb #ei #eg #ee #ec #ea #di #dg #abh #fi #ff #fd #fb #fj #eh #ef #ed #eb #ej #dh #acj #fi #fg #fe #fb #fj #eh #ef #ed #eb #ej #di #acb #fi #fg #fe #fc #fa #ei #eg #ee #ec #ea #di #acd #gj #fg #fe #fc #fa #ei #eg #ee #ec #ea #ej #acf #gj #fh #ff #fd #fa #ei #eh #ef #ed #eb #ej #ach #gj #fh #ff #fd #fb #fj #eh #ef #ed #eb #ea #adj #ga #fh #ff #fd #fb #fj #eh #ef #ee #ec #ea ---------------------------------------- ---------------- 7,part #g of #g7 ,,difference ,,in ,,degrees ,,fahrenheit ,,readings ,,between ,,wet ,,and ,,dry ,,bulb ,,thermometers4 ,,of ,,dry ,,bulb -------------------------------- ,,thermometer #bc #bd #be #bf #bg #bh #bi #cj ---------------------------------------- ---- #hj #ba #ah #af #ac #aa #h #f #d #hb #bc #bj #ah #ae #ac #aj #h #f #hd #be #bb #bj #ag #ae #ab #aj #h #hf #bf #bd #ba #ai #ag #ad #ab #aj #hh #bh #be #bc #ba #ah #af #ad #ab #ij #bi #bg #bd #bb #bj #ah #af #ad #ib #cj #bh #bf #bd #bb #ai #ag #ae #id #cb #bi #bg #be #bc #ba #ai #ag #if #cc #ca #bi #bf #bd #bb #bj #ah #ih #cd #cb #cj #bh #bf #bd #bb #bj #ajj #ce #cc #ca #bi #bg #be #bc #ba #ajb #cf #cd #cb #cj #bh #bf #bd #bb #ajd #cg #ce #cc #ca #bi #bg #be #bd #ajf #ch #cf #cd #cb #cj #bh #bg #be #ajh #ci #cg #ce #cc #ca #bi #bh #bf #aaj #dj #ch #cf #cd #cb #cj #bi #bg #aab #da #ci #cg #ce #cc #ca #cj #bh #aad #da #dj #ch #cf #cd #cb #ca #bi #aaf #db #dj #ch #cg #ce #cc #ca #cj #aah #dc #da #ci #cg #cf #cd #cb #ca #abj #dd #db #dj #ch #ch #ce #cc #ca #abb #dd #db #da #ci #cg #cf #cd #cb #abd #de #dc #da #dj #ch #cf #ce #cc #abf #df #dd #db #dj #ci #cg #ce #cd #abh #df #dd #dc #da #ci #ch #cf #cd #acj #dg #de #dc #db #dj #ch #cg #ce #acb #dg #df #dd #db #da #ci #cg #cf #acd #dh #df #dd #dc #da #dj #ch #cf #acf #dh #dg #de #dc #db #dj #ci #cg #ach #di #dg #de #dd #db #da #ci #ch #adj #di #dh #df #dd #dc #da #dj #ch ---------------------------------------- ---- ,a relative humidity of between sixty-five and seventy per cent4 should be maintained in all living and sleeping rooms1 if one is to escape colds1 catarrh1 and possibly pneumonia4 ,some nervous disorders are aggravated if not actually caused by the dryness of the air in steam and other heated apartments during the time that the windows are closed in cold weather4 ,the vanity of the female sex is appealed to with the statement that nothing is more essential to securing and preserving a good complexion than the maintaining of a proper humidity in one's own room4 ,efficient and simple and inexpensive humidifiers are now coming on the market4 ,they are almost as necessary to the health of a household as stoves and furnaces4 ,often a right degree of moisture can be created by leaving clean water in the bathtub and in all wash basins and sinks4 ,one may be surprised on taking humidity observations to find how quickly it increases in rooms two or three removed from the bathroom after water is run into the tub1 and especially if the shower spray is turned on and allowed to operate for a few minutes4 ,in cold weather we maintain the aridity of the ,sahara ,desert in our hot1 steam-heated apartments1 with a relative humidity of less than thirty per cent4 ,is it any wonder that when we step from this atmosphere into the cold outside air1 with a humidity of seventy per cent41 the violent change is productive of harm1 particularly to the delicate mucous membranes of the upper air passages1 which have been irritated and their powers of resistance weakened by the dryness within8 ,the period of pneumonia is the season of artificial heat in living rooms--or1 more properly speaking1 the period of indoor desert aridity4 ,save ,fuel by ,moistening ,air4 ,if a room at #fh is not warm enough for any healthy person it is because the humidity is too low1 and water should be evaporated to bring the moisture up to sixty-five or seventy per cent4 of saturation4 ,water instead of coal should be used to make rooms comfortable when the temperature has reached #fh4 ,ten to fifteen per cent4 of fuel could be saved in the heating of places of habitation if the air were properly and healthfully humidified4 ,the reason for this is that if the air is dry the heat passes through it and warms it but little4 ,moisture stops the radiated heat that would be lost1 absorbs it1 and holds it at the place where it is needed4 ,it has precisely the same effect as a soft wool blanket wrapped about the body of each person4 ,the dry air permits such a rapid evaporation from the human body that one may actually feel colder with a dry air heated to #ge than in a moist air at #ff or #fh4 ,water is cheaper than coal1 and in this matter much more healthful4 ,the cooling effect produced by a draught does not necessarily arise from the wind being cooler1 for it may be actually warmer1 but arises from the rapid evaporation it causes on the surface of the skin4 ,vapor of water forms a blanket about the earth and prevents it from scorching during the day and freezing during the night4 ,how to ,forecast ,weather with ,only an ,aneroid ,barometer4 ,no one except an expert observer should use the mercurial barometer4 ,the aneroid will answer as well for the purpose of forecasting from a single instrument2 it is cheaper and less complicated4 ,first learn your elevation above sea level2 then add to the observed reading of your instrument 4#aj for each one hundred feet elevation4 ,note the fall or rise and the direction of the wind and with the aid of the table on page #gf highly satisfactory forecasts may be made by any intelligent person4 ,skill will come with practice4 ,write down your forecasts each day as you make them and the following day note in a blank space left for the purpose the success or failure of your effort4 ,thus will you profit by your mistakes4 ,as a rule winds from the east quadrants and falling barometer indicate foul weather1 and winds shifting to the west quadrants indicate clearing and fair weather4 ,the rapidity of the storm's approach and its severity are indicated by the rate and the amount in the fall of the barometer4 ,this applies to the ,mississippi ,valley and eastward to the ,atlantic ,ocean4 ,conditions are different in the ,rocky ,mountains1 on the plateau of the mountains1 and on the eastern ,rocky ,mountain slope1 where precipitation seldom begins until after the barometer begins to rise after a fall1 and the winds have shifted to the northwest4 ,keep in mind that storms are great atmospheric eddies drifting from the west1 with the winds blowing cyclonically toward the center2 that when your wind is northeast the center of the storm is southwest of you2 that when it is east the center is west2 when it is south the center is north2 when it is southwest the center is northeast1 and when it is west or northwest the center is east of you4 ,,wind ,,barometer ,,reduced ,,character ,,of ,,weather ,,direction ,,to ,,sea ,,level ,,indicated ---------------------------------------- --------------------------- ,,sw4 to ,,nw4 #cj4aj to #cj4bj and ,fair1 with slight temperature steady4 changes1 for #a to #b days4 ,,sw4 to ,,nw4 #cj4aj to #cj4bj and ,fair1 followed within #b days by rising rapidly4 rain4 ,,sw4 to ,,nw4 #cj4bj and above and ,continued fair1 with no decided stationary4 temperature change4 ,,sw4 to ,,nw4 #cj4bj and above and ,slowly rising temperature and fair falling slowly4 for #b days4 ,s4 to ,,se4 #cj4aj to #cj4bj and ,rain within #bd hours4 falling slowly4 ,s4 to ,,se4 #cj4aj to #cj4bj and ,wind increasing in force1 with rain falling rapidly4 within #ab to #bd hours4 ,s4 to ,,sw4 #cj4jj or below and ,clearing within a few hours1 and rising slowly4 fair for several days4 ,s4 to ,e4 #bi4hj or below and ,severe storm imminent1 followed1 falling rapidly4 within #bd hours1 by clearing1 and in winter by colder4 ,,se4 to ,,ne4 #cj4aj to #cj4bj and ,rain in #ab to #ah hours4 falling slowly4 ,,se4 to ,,ne4 #cj4aj to #cj4bj and ,increasing wind1 and rain within falling rapidly4 #ab hours4 ,,se4 to ,,ne4 #cj4jj or below and ,rain will continue #a to #b days4 falling slowly4 ,,se4 to ,,ne4 #cj4jj or below and ,rain1 with high wind1 followed1 falling rapidly4 within #cf hours1 by clearing1 and in winter by colder4 ,e4 to ,,ne4 #cj4aj and above and ,in summer1 with light winds1 rain falling slowly4 may not fall for several days4 ,in winter1 rain within #bd hours4 ,e4 to ,,ne4 #cj4aj and above and ,in summer1 rain probable within falling rapidly4 #ab to #bd hours4 ,in winter1 rain or snow1 with increasing winds1 will often set in when the barometer begins to fall and the wind sets in from the ,,ne4 ,e4 to ,n4 #bi4hj or below and ,severe northeast gale and heavy falling rapidly4 precipitation2 in winter1 heavy snow1 followed by a cold wave4 ,going to ,w4#bi4hj or below and ,clearing and colder4 rising rapidly4 ,difference between ,weight and ,pressure of the ,air4 ,air at sea level and at #cb temperature weighs one and one third ounces per cubic foot4 ,a room twenty by twenty by ten feet contains some #ccc pounds of air4 ,the pressure of the air is a quite different thing4 ,it is the sum of the weights of all the cubic feet of air that are stacked up1 one on top of the other1 clear to the top of the atmosphere4 ,this is why the higher one goes1 the less the pressure of the air1 because there are a less number of cubic feet above4 ,and then each cubic foot weighs a slight fraction less than the one just beneath it because the air has expanded4 ,the room afore-mentioned sustains a pressure of #ehhj on its floor and a like pressure on its ceiling1 and a half of this pressure on each of the sides of the room4 ,the room does not collapse because the air exerts a like pressure on the outside of the room and the two pressures are equal--one inward and the other outward4 ,illustration3 ,,fig4 #g4--,mercurial ,barometer4 ,the glass tube on right is filled with mercury4 ,with the thumb over the open end1 it is reversed so that its open end rests under the surface in a basin of mercury on the left1 and the mercury in the tube falls to n1 at which point it is sustained by pressure of the air on surface of the mercury in the basin4 ,the ,principle of the ,barometer4 ,in #afdc some ,florentine gardeners found that they could pump water only thirty-three feet high4 ,this is because the entire volume of air1 if it were compressed to the density of water1 would equal a covering around the earth of that depth4 ,when the gardeners first began to work the plungers in their pump up and down they did not get water2 it was necessary for them first to pump out all the air in the pipe leading down to the water in the well2 then the water rose into the vacuum thus created1 and it rose to a height that just balanced the weight or pressure of the whole body of air that rests upon the earth4 ,now1 if the atmosphere surrounding the earth could be reduced to the density of mercury it would equal a covering only thirty inches deep2 this is why the mercury normally stands at thirty inches high in the vertical vacuum tube of the barometer4 7,figure #g47 ,in the complete barometer a graduated scale is attached so as to measure the fluctuations in the height of the mercury4 ,if one were to ascend in a balloon it would be found that the mercury would steadily fall with increasing altitude1 until at eighteen thousand feet one half of the atmosphere would be left below and the instrument would read only fifteen inches instead of thirty4 ,in ascending to the top of the ,washington ,monument1 #eee feet1 the pressure of the air decreases over one half inch4 ,the barometer rises and falls with the passage of storms because wind movement displaces air and causes it to accumulate at some places and become deficient at others1 but in order to compare barometers exposed at many different elevations with the view of determining the geographic position of storm centers--of cyclones and anti-cyclones--it is necessary to reduce all barometric readings to sea level4 ,weather ,records ,turn the ,scales of ,justice4 ,how trivial the incident that may change the whole course of a lifetime and lead to peace and happiness or to discord and sorrow6 ,likewise the parting of the clouds and the coming through of the sunshine1 or the moment of the beginning of rainfall1 or the amount of rain that falls within a given time1 or the direction of the wind1 or the velocity of the wind1 or the temperature of the air1 or the depth of the snowfall literally thousands of times has furnished the evidence in courts of law that has turned the scales of justice in civil suits involving large sums of money1 and in criminal cases where a prison sentence or the hangman's noose threatened the defendant4 ,for illustration let us say that a ship breaks from its mooring1 crashes into another ship in the harbor and sinks it4 ,if the force of the storm is no greater than has previously occurred in that harbor1 the first ship is liable for the loss of the second ship4 ,but if the automatically recording instruments of the ,weather ,bureau show that at that time the velocity of the wind was greater than ever had been known before1 then the loss is due to 8an act of ,god0 and the ship that broke her mooring is not liable for damages to the ship that was sunk1 provided proper provision was made for such velocity of wind as reasonably might be expected to occur with the passage of a storm4 ,to cite a case that actually occurred3 ,a railroad company was sued for the loss of a million dollars' worth of lumber that was burned1 as alleged1 by sparks from one of its locomotives4 ,here came in the wind records of the ,government and proved that at the time of the starting of the fire the wind was steadily and forcefully blowing in a direction opposite to what would carry the sparks to the lumber1 and the company was protected against an unjust verdict4 ,again heavy rain fell in excess of the capacity of the sewers of a city to carry away the water1 and private property was damaged by the flood4 ,in this case the city was compelled to pay for the damage to property1 because the records of the ,weather ,bureau showed that previous rainfalls had been of equal or greater amount in the same period of time1 and the city should have constructed its sewers of sufficient capacity to carry away such precipitation as experience showed was liable to occur4 ,the writer was once an expert witness in what then was a famous case4 ,the defendant1 a young and handsome woman previously of unimpeachable character1 was being sued for divorce4 ,two witnesses swore that they had seen her come to an open window1 facing south1 at seven o'clock in the morning1 in a house in which she should not have been1 stand for several minutes looking into the garden upon which the window faced1 clad only in her night robe4 ,unfortunately the woman was not able to establish a satisfactory alibi for the morning in question1 and she stood facing a terrible calamity with no power to establish her innocence4 ,her accusers had given as a reason why she stood so long at the open window that the morning was warm and balmy4 ,but1 fortunately for the innocent woman1 the weather records came to her defense when her case seemed hopeless and her life was about to be blighted with a scandal from which she never would be able to free herself1 and proved that at the very time when she was supposed to have been standing in the open window a torrential rain was falling and a wind of fifty miles per hour was beating upon the outside of the window panes4 ,the woman was acquitted and one of the witnesses spent several hundred balmy mornings behind prison bars4 ,at another time the writer came into a case where a robber had shot and killed a citizen who surprised him in the committing of his crime4 ,the robber was on trial for murder and his lawyers were attempting to clear him by the introduction of evidence to prove that the day was so foggy that the ,state's witnesses had blundered and seized the wrong man when they chased the murderer around a corner4 ,the weather expert destroyed the only evidence that tended to raise a doubt in the mind of the jury as to the man's guilt1 by testifying that fog could come to the surface of the earth only when the air was abnormally light and the wind calm or only gentle2 while at the time of the murder the barometer was unusually high and the wind brisk4 ,here again the meteorological records aided in vindicating the right1 and secured the conviction and execution of a brutal murderer4 ,a remarkable case was that in which a tramp was being tried for the murder of a miserly old woman who was believed to carry a large amount of money about her person4 ,the tramp came to her door and asked for food4 ,she took him in and fed him and soon thereafter he was seen hastily to leave the house4 ,an hour after he had gone the woman was found murdered and her clothing rifled4 ,the tramp was overtaken1 found to have a large amount of money of small denominations in his pockets1 indicted1 and placed on trial4 ,the principal witness for the ,state was a man who was repairing a frozen water pipe in a trench by the side of the house opposite to that by which the tramp entered and left4 ,he saw the blow struck1 ran in fear to his home1 and then informed the police4 ,in explaining how he came to see the criminal act1 he testified that he climbed out of the trench to get a drink from a bucket standing near by1 and as he raised the bucket his eye came in line with a window of the house1 through which he witnessed the murder4 ,the case seemed clear against the tramp1 as other witnesses had seen him enter and leave the house and positively recognized him4 ,just here his lawyer asked the trench digger how long the water bucket had been sitting by the side of the trench4 ,the latter said it had been there from #g o'clock until #aj4 ,then the weather records came in to confound the falsifier and to vindicate innocence1 for the automatic tracing of the pen that records every movement of the temperature proved that the temperature had not been above zero any time during the three hours that the bucket had been exposed and that it contained a solid chunk of ice if it contained anything4 ,the trench digger then confessed that he himself was the murderer4 ,he had seen the tramp enter and leave and thought it a favorable opportunity to commit the crime and put the evidence on another4 ,,chapter ,,vii ,,frost ,there is nothing in the study of the atmosphere that so intimately concerns the horticulturist and the gardener as knowledge of the conditions under which frost forms1 and the methods that may be pursued to gain immunity from its disastrous effects1 or to lessen the loss4 ,frost does not necessarily form from air that has fallen to the freezing point1 as many suppose4 ,on the contrary1 the air ten feet or less above the vegetation may be several degrees above freezing when there is a heavy and destructive frost upon vegetation4 ,the fact is that vegetation radiates heat towards a clear sky faster than does the air and may fall to the freezing point or below2 while the air1 except the molecules actually in contact with the vegetation1 is considerably warmer4 ,frost is not frozen dew4 ,the water vapor is precipitated1 or rather congealed1 upon the vegetation without passing through the liquid state at all4 ,frost is spoken of as light1 heavy1 and killing4 ,tomato plants are killed by only a light touch of frost1 while fruit blossoms will stand several degrees of cold below freezing4 ,therefore the tomato grower would consider as killing a frost that to the fruit grower would only appear as light4 ,the radiation of heat from the earth is continuous both day and night when there are no clouds to obstruct the passage of the heat rays4 ,the amount received from the sun during the day is greater than the loss by radiation from the earth and the temperature of the air rises4 ,after the setting of the sun the radiation of the earth goes on but there is no incoming heat from the sun to offset the loss and the temperature of the air falls4 ,as previously stated1 the soil and vegetation radiate faster than the air and the air in immediate contact with the soil is cooled by conduction to it4 ,thus over a level plain on a clear calm night there is found a relatively thin layer of cold air near the ground1 which increases in temperature up to two hundred or three hundred feet1 or which may be only five or ten feet deep4 ,over sloping ground the force of gravity tends to cause this thin surface layer of cold air to move down the slope and to gather in depressions in somewhat the same manner as water would move4 ,such movement is called ,air ,drainage4 ,of course this air is slowly gaining heat by compression as it passes to lower levels1 but it is hugging closely to the cold earth and losing by conduction much or all that it thus gains by compression4 ,after a study of the contour of the region with respect to air drainage the writer purchased a considerable tract of land near ,rockville1 ,montgomery ,county1 ,maryland1 and planted extensive orchards thereon1 with the result of harvesting nine successful crops of fruit in a period of ten years after the trees became large enough to bear4 ,with the composition and the surface covering of the soil the same1 the low places in a field are always the ones that suffer most when frost is possible4 ,figure #h shows a minimum temperature of #be to have occurred at the base of a steep hillside when on the higher ground at an elevation of but fifty feet the lowest temperature was #dd1 and at two hundred and twenty-five feet up the mountainside the minimum was #eb4 ,illustration3 ,,fig4 #h4--;,continuous records of the temperature from #d ,p4,m4 to #i ,a4,m4 at the base and at different heights above the base of a steep hillside1 showing the great differences in temperature that sometimes develop on a clear1 still night4 ,although the temperature at the base was low enough to cause considerable damage to fruit1 the lowest temperature #bbe feet above on the slope was only #ea4 ,note that the duration of the lowest temperature was much shorter on the hillside than at the base4--,weather ,bureau4 ,in selecting a location for an orchard it is not so much a problem of elevation above sea level as elevation above the surrounding region4 ,the direction in which the slope faces makes little difference4 ,the prime consideration is to get sufficient air drainage to gain the greatest protection against frost without selecting land with such a steep slope as to furnish excessive soil drainage and which would be difficult to cultivate and move about upon in the spraying of trees and in the picking of fruit4 ,in the ,maryland orchard the elevation was only five hundred feet above sea level and only about two hundred feet above the surrounding region1 and the slope was so gradual as almost to be imperceptible to one passing over it4 ,after nightfall the air on mountain peaks and on hills and ridges soon becomes cooler than the air at the same elevation out over the open valley1 due to contact with the elevated earth1 which radiates heat and cools faster than the air4 ,water vapor has a great capacity for heat4 ,it is the most effective of the various gases present in the atmosphere in obstructing radiation of heat from the earth1 as well as in absorbing incoming radiation from the sun4 ,the night temperature1 therefore1 falls more slowly when the relative humidity is high than when it is low1 that is to say1 when the air is nearer saturation1 or nearer its dew point4 ,drops of water that collect on the outside of a pitcher of ice water on a warm day are formed through the chilling of the air in contact with the pitcher2 they begin to form as soon as the temperature of the pitcher reaches the dew point of the air1 which temperature varies in accordance with the amount of water vapor present in the air at the time4 ,after sundown the temperature of exposed objects falls1 of some faster than others1 depending on their capacities for radiation4 ,vegetation radiates freely and often falls to the dew point of the air1 at which time dew begins to form on it and continues to be deposited as long as the temperature remains above freezing4 ,now1 here carefully note that if the dew point is above #cb the condensation of water vapor in the form of dew liberates latent heat1 which usually will be sufficient to check the fall of temperature and prevent the formation of frost4 ,if the dew point of the air is #cb or lower frost forms4 ,if the dew point is very low the temperature may fall low enough to cause much damage without the formation of any frost4 ,as an example1 if the dew point be #bj and the temperature falls to #bd much damage might be done to growing crops and no frost appear4 ,this phenomenon is called black frost2 it seldom occurs4 ,from the foregoing it might be assumed that the possibilities of frost might safely be forecast from an observation to determine the relative humidity taken early in the evening1 but unfortunately experience has shown that reliance cannot be placed in such method of forecasting1 as the humid air of early evening may be displaced by much drier air before the hour of minimum temperature the next morning4 ,one of the best locations to gain immunity from frost at the critical period of plant growth is immediately to the leeward of a considerable body of water4 ,wind blowing from a large body of water is always heavily laden with moisture1 which decreases the rate of radiation both day and night1 but especially during the period of cold in the early morning when frost is liable to occur4 ,such winds1 largely affected by the temperature of the water over which they have passed1 modify the temperatures of both day and night4 ,the all-important condition for the formation of frost is an atmosphere already cool1 with a gentle northwest wind and a clear sky1 which condition1 with more or less coolness1 always accompanies the high barometric areas that follow the low-pressure areas of warmth1 cloudiness1 and moisture4 ,at an expense of two millions of dollars per annum the ,government maintains some two hundred observation stations of the ,weather ,bureau1 and twice daily telegraphs observations to all the large cities of the nation1 but unfortunately in many cases these are not published for the benefit of the people who could make valuable use of them4 ,the ,bureau's own deductions from these observations1 in the form of forecasts and warnings1 are extremely valuable1 but an even greater service could be rendered the public by neatly lithographing an evening weather map and mailing it from all large cities each night1 so that every intelligent person whose business is affected by the weather could1 through a study of the chapter on ,forecasting in this book1 judge for himself as to the effect that the coming weather may have on his particular interests4 ,one could then watch the movements of the high barometric areas and the low areas and become weatherwise himself1 and he who studied these charts the most diligently would have an advantage over less progressive competitors4 ,evaporation goes on at all temperatures1 even below freezing and from solid ice1 its rate1 of course1 being diminished by low temperatures4 ,at times1 in spring or fall1 the temperature of the air over rivers1 when there is little wind1 falls so far below the temperature of the water that the water vapor rising from the river by evaporation is quickly condensed in the form of fog1 which may cover a part or all of the low contiguous land1 checking radiation and preventing a further fall in temperature4 ,in valleys near the ocean1 fog sometimes drifts in from the water when frost is imminent and prevents its formation4 ,on nights with fog1 contrary to the usual condition1 the hillsides are always colder than the lowlands1 unless the fog extends high enough to cover them4 ,in #ahia-ahid the writer1 in studying the conditions under which frost forms on the cranberry bogs of ,wisconsin1 was impressed with the fact that the occurrence of frost on a given field depended as much on the character of the surface and its covering as it did on the temperature of the air a few feet above1 one place receiving an injurious frost1 another a light frost1 and still another none at all1 while each had the same conditions as to temperature1 wind velocity and direction1 and all were at the same elevation1 so that the differences could not be accounted for by air drainage4 ,in one case the marsh was cleanly cultivated and covered with sand1 in another there was clean cultivation but no sand1 and in still another case there was a thick growth of vegetation4 ,as the result of a long series of observations conducted by ,professor ,h4 ,j4 ,cox1 working under the directions of the writer1 minimum thermometers were placed among the vines over newly sanded surfaces in two marshes1 one at ,cranmoor and one at ,mather1 ,wisconsin4 ,the locations selected for this inquiry represented the best results that could be secured from sanding1 draining1 and cultivating4 ,comparison was made at each marsh between the readings taken close to the vines of the clean part of the marsh and those taken close to the surface over the unsanded peat bog4 ,the average lowest night temperature over the sand for the four months was #e4i higher than over the peat at ,cranmoor1 and #d4b at ,mather4 ,on one night the minimum over the surface at ,cranmoor was #ab higher than over the peat1 while at ,mather a difference of nine degrees was recorded on another night4 ,through cultivation the marsh may be kept free from weeds1 moss1 or other rank growth1 thus permitting the sun's rays to reach the soil and increase its temperature during the day1 while a growth of thick vegetation screens the soil from the sun's rays1 and there is consequently less heat in the latter soil to be given out during the hours of low temperature at night4 ,drainage lowers the specific heat of the soil and decreases the cooling effect of evaporation4 ,therefore1 under sunshine1 the dry soil becomes warmer than the wet and1 whether or not it has a greater quantity of heat to give off at night1 it has a higher temperature and therefore radiates more freely to the air above4 ,a covering of sand likewise lowers the specific heat of the surface and thereby causes it to gain a higher temperature during the day than an unsanded surface receiving the same solar rays4 ,it therefore radiates more rapidly at the critical time when heat is needed to prevent the temperature of vegetation from falling to the freezing point and gaining a deposit of frost4 ,illustration3 ,,fig4 #i4--;,continuous records of the temperature #e feet and #ce feet above ground on a tower in a pear orchard4 ,note the large difference in temperature at the two levels before the orchard heaters were lighted at #d ,a4,m4 ,by #e ,a4,m4 the temperature was practically the same at the two levels1 showing that the heat from the burning oil had been nearly all expended in raising the temperature of the air within #ce feet of the ground4 ,this point is further illustrated by the fact that at #e ,a4,m4 when most of the heaters were extinguished1 the temperature at the #e-;foot level fell rapidly1 while it remained practically stationary at the #ce-;foot level4--,weather ,bureau4 ,in many orchards in the ,rocky ,mountain ,states1 where fruit growing is highly profitable and the injury from frost more than probable every year1 an extensive use is made of oil and other fuel-burning heaters between the rows of trees4 ,those who wish further information with regard to this matter should send to the ,weather ,bureau1 ,washington1 ,d4 ,c41 for ,farmers' ,bulletin ,no4 #ajif4 ,at first thought it would seem that heat so applied would be blown away or instantly escape upward4 ,but on frosty nights there is not much wind2 if there is1 there is little danger from frost4 ,and then1 as previously stated1 on such nights there is what is called temperature inversion1 and the temperature actually rises with the first few feet of ascent1 and the heated air soon reaches air of its own temperature1 when no further ascent occurs4 ,when the air forty feet from the ground is ten degrees warmer than it is around and in contact with vegetation1 as often occurs on frosty nights1 the heat from the fires is nearly all expended in raising the temperature of the air within this forty feet4 ,figure #i furnishes the result of an experiment illustrating the correctness of the foregoing theory4 ,illustration3 ,,fig4 #aj4--;,average dates of last killing frost in spring4 ,illustration3 ,,fig4 #aa4--;,average dates of first killing frost in fall4 ,figures #aj and #aa show the average dates of the last killing frost in spring1 and of the first killing frost in fall4 ,,chapter ,,viii ,,wind ,,and ,,pressure ,,of ,,the ,,globe ,,cause ,,of ,,local ,,winds ,,and ,,of ,,general ,,circulation ,general ,circulation4 ,differences in temperature1 changing the specific gravity of the air1 are the cause of the general circulation of the atmosphere about the earth1 modified by the rotation of the earth2 likewise the local circulation between land and water is caused by the different quantities of heat radiated by the two widely differing forms of matter1 each attaining to a different temperature under the influence of the same solar radiation2 and the inflow of winds to the cyclone and the outflow from the anti-cyclone are due to the same forces that cause the general and the local circulations4 ,if there were no difference in temperature between the equator and the poles the atmosphere would soon adjust itself in accordance with the laws of gravity1 modified by the centrifugal force developed from the rotation of the earth1 and the atmosphere forever would be at rest relative to the earth1 moving with it as if it were a part of the solid sphere throughout its diurnal rotation on its axis and its annual movement about the sun4 ,but there is a decided difference in temperature between the equator and the poles and between land and water surfaces2 hence a general circulation1 modified and distorted by numerous local movements1 which1 in turn1 may be modified by the height of hills and mountains and the direction of their trend4 ,illustration3 ,,fig4 #ab4--,trade wind circulation and reason for belts of high pressure at latitudes #cj ,n4 and ,s4 that extend around globe as shown by ,figure #ac4 ,let us trace a current of air through its course as shown in ,figure #ab and the reason for the blowing of the trade winds will be apparent1 as will the reason for the location of a belt of high pressure at latitudes #cj north and south encircling the globe4 ,at the equator there is a belt of calms4 ,here the air gently ascends under the intense heat of vertical sunshine4 ,it is humid1 for there is much water surface in the region of the equator1 and the air carries vast quantities of water vapor aloft1 later to be precipitated as torrential rains in the ,tropical ,zone1 as the air cools by expansion in its ascent4 ,this air expands or bulges upward and overflows aloft northward and southward1 causing low air pressure at the equator1 because of the quantity of air moved to other latitudes1 which more than compensates for the amount banked up over the equator by the centrifugal force of the earth's rotation4 ,illustration3 ,,chart #a4--;,,high ,,and ,,low ,,centers ,,of ,,action ,,and ,,prevailing ,,winds ,,of ,,the ,,globe ,,for ,,july 7,buchan74 ,since air1 passing away from the equator1 must pass successively over parallels of latitude having less easterly velocity than that with which it started its journey1 it runs ahead of the earth1 and1 relative to the surface of the earth1 has a direction from the southwest north of the equator1 and from the northwest south of the equator4 ,our current was divided at an altitude probably of six miles above the equator1 one half following the northern and the other half the southern circuit4 ,it was cooled by elevation and by radiation outward to space and as a result gained in weight and gradually descended1 reaching the earth at about latitudes #cj north and south1 and causing an accumulation of air at those latitudes and the belt of high pressure that irregularly surrounds the earth4 ,in descending in the belt the air breaks up into a number of anti-cyclonic systems1 sub-permanent highs or ,centers of ,action1 which have so much to do with initiating the migratory ,highs and ,lows that create the weather of the earth1 as will be fully explained in the ,chapter on ,weather ,forecasting4 ,the intensity of these centers of action is modified and their geographic positions shifted with change of season4 7,see ,charts #a and #b47 ,illustration3 ,,chart #b4--;,,high ,,and ,,low ,,centers ,,of ,,action ,,and ,,prevailing ,,winds ,,of ,,the ,,globe ,,for ,,january 7,buchan74 ,trade ,winds4 ,but to return to the current that we left as it divided above the equator 7,figure #ab7 and descended on an inclined plane to latitudes #cj north and south4 ,it is cooler and dryer and heavier than when it started to ascend and it has lost the thousand miles per hour and more easterly velocity that it had at the equator and now only has the velocity that belongs to latitude #cj2 therefore as it moves toward the equator from either side it lags behind latitudes whose easterly velocity is greater1 and it takes up a direction partly toward the west1 which1 relative to the earth1 makes it a northeast wind in the ,northern ,hemisphere and a southeast wind in the ,southern ,hemisphere4 ,and thus is established a circulation the lower part of which is known as the 8trade winds40 7,figure #ac47 ,navigators profit largely by availing themselves of the west winds in the middle latitudes and of the east winds in the tropics4 ,to the daring and persistence of ,columbus1 and the force and constancy of the trade winds which blew him westward1 we owe the discovery of ,america4 ,illustration3 ,,fig4 #ac4--;,average surface winds and pressure of the globe4 ,winds of ,middle ,latitudes4 ,now study ,figure #ab and associate the information it conveys with that of ,figure #ac1 and observe that from the two belts of high pressure the air is pushed outward on both sides4 ,in each case it starts as a true north or south wind1 but1 due to the rotation of the earth1 is always and everywhere deflected to the right in the ,northern ,hemisphere and to the left in the ,southern ,hemisphere1 and this deflection increases until what started as a poleward wind in the middle latitudes soon becomes almost a due west wind4 ,in this region of west winds cyclonic storms are more frequent than in any other part of the globe4 ,now get clear in the mind the fact that no matter what may be the direction of the wind inside a cyclonic or anti-cyclonic whirl 7often one thousand miles in diameter71 the whirl is carried toward the east by the general drift from the west of the winds between latitudes #cj and #fj1 and toward the west in the region of the trade winds4 ,low ,barometer at the ,poles4 ,even though the air is contracted and rendered denser by the great cold of the ,arctic regions1 the pressure remains low because of the quantity of air driven equatorward by the centrifugal force both of the earth and of the winds themselves as they rim ahead of the earth and encircle the globe in the middle latitudes4 ,data too ,meager to ,show ,full ,circulation ,aloft of the ,atmosphere of the ,globe4 ,many charts have been published in the attempt to show how the atmosphere circulates below and aloft through the whole world4 ,they only have speculative value1 as our knowledge is too limited to permit us to unravel the complexities of all the upper movements4 ,rain ,winds of the ,tropics4 ,the trade winds1 mostly moving over water surfaces1 are laden with moisture1 but1 gaining temperature as they move towards the equator1 their capacity to hold water vapor steadily increases1 and therefore they do not become rain winds unless forced to ascend by the interposition of mountains1 or until cooled by ascension at the equator4 ,in no part of the world does the air rise so steadily and in such great volume as in the equatorial belt of calms and low pressure4 ,hence this is the region of greatest rainfall4 ,during the two rainy seasons1 spring and fall1 the day opens clear2 near midday the clouds gather and rain falls early in the afternoon2 after which it quickly clears4 ,this is so regular a program that one lays his plans accordingly4 ,there is almost no rain in ,december and ,january2 this is because the belt of calms and the inflowing trade winds move northward and southward with the migrations of the sun1 and in ,december and ,january1 the sun being far south1 the northern trades1 with their rainless winds1 cover the equator and the region formerly occupied by the belt of calms4 ,in midsummer the sun is far north and then the southern trades move up and give dryness to the equator4 ,in the northern trades1 of the moderate amount of rain that falls1 the greater quantity falls in summer2 in the southern trades the order is reversed4 ,rain of the ,high-,pressure ,belts and of the ,regions of ,west ,winds4 ,in the high-pressure belts the air is settling down and gaining heat by compression and there is not much horizontal movement4 ,these are1 therefore1 regions of but little rainfall1 and all the great deserts occur in or near them4 ,the belts of west winds are the regions of most frequent cyclonic activities4 ,here the rainfall is quite equally distributed throughout the year and is the result of the mixing of the air by storms and its cooling by expansion as it is carried upward in the migrating whirl4 ,circulation between ,continents and ,oceans4 ,in ,chapter ,x1 under the sub-caption 8,influence of ,continents and ,oceans on ,climate01 the circulation between them is well explained4 ,in general the movement is from the continent to the oceans in winter1 with the air flowing inward aloft to settle down and take the place of that which passes out to sea4 ,in summer the directions are reversed4 ,daily ,variation in ,coastal ,winds4 ,in summer1 when there are no forceful storm winds blowing steadily from one direction for several hours at a time1 there will daily spring up gentle to fresh winds from the surface of oceans and large lakes to the land1 because of the influence of the sun's rays in heating the land to a higher temperature than it does the water4 ,these winds will not appear on cloudy days and they will extend inland but a few miles4 ,monsoon ,winds4 ,during winter the vast continent of ,eurasia 7,europe and ,asia7 cools to such an extremely low temperature as to develop a ,high1 or center of action1 of great energy and extent1 which drives a steady dry monsoon into the ,indian ,ocean and ,china ,sea4 ,unlike the trade winds1 these winds reverse their direction in the summer2 then the intense heat of the continent to the north develops an extensive ,low1 which draws the ocean winds inland and extends its influence so far south as to attract the southeast trade winds of the ,southern ,hemisphere and1 turning them so that they flow from the southwest1 continue them far into the interior of ,asia4 ,since the summer monsoon blows from a tropical sea it comes heavily laden with water vapor and as it rises over the mountains of the great ,himalayan system copious rains are precipitated4 ,in ,australia1 ,africa1 ,south ,america1 and some parts of the ,north ,american continent monsoon influence in various degrees is felt1 but in no place is the monsoon so important as in the countries bordering the ,indian ,ocean4 7,charts #ae and #af47 ,fhn ,winds4 ,this is a hot wind that sometimes blows down a mountain side in the ,alps4 ,in the ,rocky ,mountains it is called the ,chinook ,wind4 ,it is caused by moisture-laden air being drawn over a high mountain so quickly that the heat liberated in condensation does not have time to escape by radiation4 ,the air cools by expansion as it ascends on the west side of the mountain1 but it gains this all back by compression as it descends1 and it has added to its temperature much of the heat of condensation4 ,it is dry and greedily evaporates snow from the ground in winter1 clearing off a deep covering within a few hours4 ,illustration3 ,,fig4 #ad4--;,how winds would blow into a cyclone on a non-rotating earth4 ,how ,winds ,are ,deflected by ,earth's ,rotation4 ,every free-moving thing1 whether wind or projectile1 is deflected to the right of its initial direction by the rotation of the earth in the ,northern ,hemisphere and to the left in the ,southern ,hemisphere1 unless the object be moving exactly along the line of the equator4 ,winds moving inward to a ,low are therefore so deflected as to cause the cyclone to gyrate in a direction contrary to the movements of the hands of a watch4 ,in an anti-cyclone the movement is with the watch4 ,in the ,southern ,hemisphere these wind directions are reversed4 ,figure #ad gives an illustration of what would be the movement of air inward to a cyclone on a non-rotating earth4 ,the winds would blow along radial lines for a time1 but1 converging together as they began to ascend1 they doubtless would soon set up a gyration about the center4 ,on a non-rotating earth this gyration would be clockwise as often as it would be anti-clockwise1 but on a rotating earth the gyration can be in but one direction4 7,figure #ae47 ,even tornadoes1 whose diameters of rotation are never but a few hundred feet1 obey this law4 ,in little dust whirls1 in which the movements of air may be comprehended from the motion of the trash that is whirled about and which are tornadoes in miniature1 the direction of gyration may be either way4 ,they are too small for the deflecting force to be appreciable1 and it may be that the tornado is forced to take its direction of gyration from the cyclone in whose southeast quarter it has its origin4 ,illustration3 ,,fig4 #ae4--;,deflection of wind due to earth's rotation4 ,how ,wind ,velocity ,increases with ,altitude4 ,figure #af shows how the velocity of the wind increases with elevation in the free air up to five thousand meters 7about three miles74 ,the average for the year1 for the summer and for the winter1 is given4 ,it increases most rapidly up to six hundred meters in summer and up to eight hundred meters in winter4 ,from these two heights there is a steady and pronounced slowing down of the wind up to one thousand meters2 after which it increases up to five thousand meters1 and how far beyond we know not4 ,in winter there is a singular acceleration of velocity in the stratum between two thousand and twenty-five hundred meters and then no increase for the next five hundred meters2 after which there is a uniform and steady gain up to five thousand meters4 ,starting at two hundred and seventy meters1 the average velocity for the year is #c meters per second1 or about #g miles per hour4 ,at five thousand meters altitude the average for the year is #aa meters per second1 or about #bg miles per hour4 ,illustration3 ,,fig4 #af4--;,annual1 summer1 and winter wind velocities1 with altitude4 #a1 #ahej feet2 #b1 #bdfg feet2 #c1 #cjhc feet2 #d1 #ae1dag feet4 ,,chapter ,,ix ,,how ,,to ,,forecast ,,from ,,the ,,daily ,,weather ,,map ,,it ,,is ,,not ,,difficult ,,to ,,become ,,weatherwise ,,and ,,thereby ,,to ,,gain ,,advantages ,,in ,,health1 ,,happiness1 ,,and ,,business ,the person who will take the time to learn to interpret the daily weather map has a decided advantage over those who are less progressive4 ,the maps may be secured by applying to any ,weather ,bureau station4 ,many members of commercial associations1 having the advantage of seeing the large glass weather map that is made each morning by an observer of the ,weather ,bureau and displayed on the floor of the association1 have become expert weather forecasters4 ,the value of the principal crops of the country is largely influenced by the weather1 as are the prices of transportation and industrial stock2 and there is hardly a business that directly or indirectly is not influenced by the prospects of coming weather4 ,vessel masters1 long accustomed to forecast the near approach of storms from the action of their 8glass0 7barometer71 now have learned that the daily weather map shows them at a glance the height of not one but of many barometers scattered over a wide area and read at the same moment of time4 ,they see that the direction and the force of the wind are the results of differences in air pressure2 that the air flows from a region where the air pressure is great1 that is to say1 where the barometers are high1 towards a region where the pressure is less1 or where the barometers are low2 and that the velocity of the wind will be in proportion to the difference in the pressure of the air4 ,coast-wise and lake shipping are therefore not only affected by the forecasts made by the ,weather ,bureau but by the forecast made by the masters themselves when they can get access to the daily weather map4 ,their own lives and the lives and property of others are in their keeping4 ,but the great mass of intelligent people have no idea of the methods employed in the making of the weather map and of the many and widely diversified uses to which a study of its data would lead4 ,one first must learn of the simple manner in which the map is constructed2 then1 by a comparison of the map each day with the preceding chart1 he soon will be able to detect the beginning of storms1 trace them through their various migrations as they cross the continent and finally pass out to sea1 bidding them bon voyage as they go in quest of a more eastern continent on which to bestow their blessings of rain and active1 purified air2 or1 as it often may happen1 shuddering for the fate of the mariner who is caught in their fierce vortical whirls1 and for the land areas that may be laid waste by their gyrating force4 ,how the ,weather ,map ,is ,made4 ,at #h ,a4,m4 to-day ,washington time1 which1 by the way1 is about seven o'clock at ,chicago1 six at ,denver1 and five at ,san ,francisco1 the observers at some two hundred stations in the ,united ,states and contiguous territory were taking their observations and from carefully standardized instruments noting the conditions of the atmosphere4 ,by #h3bj ,a4,m4 the barometers at each station have been reduced to sea level1 that is to say1 they have been made to read what they would if they were located at the level of the ocean4 ,thus differences in air pressure that are due to differences in elevation are eliminated1 so that they may not obscure those due to storm conditions4 ,then1 for purposes of brevity and accuracy1 the observations are reduced to cipher form1 and each filed at the local telegraph office4 ,during the next thirty or forty minutes the observations1 with the right of way over all lines1 are speeding to their destinations1 each station contributing its own report1 and receiving in return such observations from other stations as it may require4 ,the observations from all stations are received at such important centers as ,washington1 ,new ,york1 ,chicago1 and other large cities having ,weather ,bureau stations1 and from these centers daily weather maps are printed and issued at #aa ,a4,m4 each day4 ,illustration3 ,,chart #c4--,,winter ,,storm1 ,,december #ae1 #ahic1 #h ,a4,m4 ,black lines connect places having equal barometric pressure2 arrows point in direction wind is blowing2 figures at end of arrows show wind velocity1 when it is more than light4 clear2 partly cloudy2 cloudy2 ,r rain2 ,s snow4 ,,high indicates center of anti-cyclone1 or high-pressure area2 ,,low indicates center of cyclone1 or low-pressure area4 ,large figures show average temperature in each quadrant of cyclone4 ,now turn to ,chart #c4 ,heavy black lines 7isobars1 meaning equal pressure7 are drawn through places having the same barometric reading4 ,the readings are omitted from the printed ,chart4 ,by drawing lines for each difference of one tenth of an inch1 the high and the low-pressure areas 7called ,highs and ,lows7 are soon inclosed in their proper circles4 ,these lines run in oval or circular form1 indicating that storms operate in the form of great atmospheric eddies2 that there are central places of attraction towards which the air is drawn if the disturbance be a low-pressure area1 with its usual accompaniments of warm1 moist1 and often rainy weather1 and from which the air is driven if it be a high-pressure area1 with cool1 settled weather4 ,the word 8,high0 is written inside the isobar marked #cj4f1 located in southern ,oregon1 and the same word is written inside the isobar marked #cj4d1 located on the ,south ,atlantic coast1 and also inside the isobar #cj4jd1 which traverses ,nova ,scotia4 ,these are the regions of great air pressure4 ,the word 8,low0 is written at the center of the area inclosed by the isobar #bi4f1 which is situated in the ,state of ,iowa4 ,the latter is the region of least pressure4 ,sometimes there are several such regions shown on the weather map4 ,why the ,wind ,blows4 ,under the pull of gravity the atmosphere presses downward and outward1 thus causing it to flow from the several regions of great pressure towards regions of less pressure4 ,observe the arrows1 which fly with the wind1 and it will be seen how generally this law is obeyed4 ,the velocity with which the wind moves from the ,high toward the ,low depends on differences in air pressure1 modified in the lower stratum by the friction offered in passing over surfaces of varying degrees of roughness1 the speed being greater over a water surface with the same difference in air pressure than over a level unwooded prairie1 and greater over the open prairie than over an irregular wooded area4 ,to illustrate3 ,if the barometer were #cj4e at ,bismark1 ,dakota1 and #bi4e at ,chicago1 it would press upon the earth with a force of about seventy pounds greater per square foot at the first place than at the second4 ,this difference in pressure would cause the air to flow from ,bismark towards ,chicago so rapidly that after allowing for the resistance due to friction on the earth there would remain a velocity of some fifty miles per hour1 and ,lake ,michigan would experience a severe 8,northwester02 and if the wind continued from the same direction for twenty-four hours a mighty sea would beat upon the eastern shore of the lake1 and mariners and marine property would be at the mercy of a destructive tempest unless the ,weather ,bureau forecaster were alert and gave warning as soon as he saw such a juxtaposition of pressure distribution in the process of formation4 ,we will give careful attention to this chart1 for when its details are understood1 others will be easily read4 ,the chart shows a winter storm central in ,iowa on ,december #ae1 #ahic4 ,the word 8,low0 marks the storm center4 ,it is the one place in all the ,united ,states where the barometer reading is the lowest4 ,the heavy black lines1 oval and nearly concentric1 about the ,low1 show the gradation of air pressure as it increases quite uniformly in all directions from the center of the storm outward4 ,the arrows fly with the wind1 and1 as will be seen1 almost without exception are moving towards the ,low1 or storm center1 clearly demonstrating the effect of gravity in causing the air to flow from the several regions marked 8,high01 where the air is abnormally heavy1 toward the ,low1 where the air is lighter4 ,as the velocity of water flowing down an inclined plane depends both upon the slope of the plane and the roughness of its surface1 so the velocity of the wind1 as it flows along the surface of the earth towards the storm center1 depends on the amount of the depression of the barometer at the center and the resistance offered by surfaces of varying degrees of roughness4 ,storms and ,cold ,waves ,simply ,great ,eddies in the ,atmosphere4 ,now picture in your mind that all the air inside the #cj4b isobar1 as it flows inward1 is rotating about the ,low in a direction contrary to the movements of the hands of a watch1 and you have a fair conception of an immense atmospheric eddy4 ,have you ever watched the placid waters of a deep-flowing brook and observed that where the waters encountered a projecting rock little eddies formed and went spinning down the stream8 ,well1 our storms are somewhat similar eddies in the atmosphere1 more or less perfect1 that are carried along by the general easterly movement of the atmosphere in the middle latitudes of both hemispheres4 ,but they are not deep eddies2 the ,low marks the center of an atmospheric circulation of vast horizontal extent as compared with its thickness or extension in a vertical direction4 ,thus a storm area extends from ,washington1 ,d4 ,c41 to ,denver1 ,colorado1 and yet extends upward only about six miles4 ,the whole disk of whirling air1 six miles thick and two thousand miles in diameter1 is called a cyclone1 or low-pressure area4 ,it is important that a proper understanding be had of this fundamental idea1 since the weather experienced from day to day depends almost wholly upon the movement of these migrating cyclones1 or areas of low pressure1 and the anti-cyclones1 or areas of high pressure4 ,the temperature readings are omitted from each station1 but the average temperature of each quadrant of the ,low is shown by the large black figures4 ,the greatest difference in temperature is seen to be between the southeast and the northwest sections4 ,this is due in part to the fact that in the southeast quadrant the air is drawn northward from warmer latitudes1 and in the northwest quadrant it is drawn southward from colder latitudes1 and to the further fact that winds blowing into the west side of a ,low have a downward component of motion1 and those blowing in on the front1 or east side1 have an upward component4 ,one should gain a clear idea of the difference between the movements of the air in the cyclone and the movement of the cyclone itself1 or its translation from place to place2 how the wind must blow into the front of the storm in a direction partly or wholly contrary to the movement of the storm itself1 and into the rear of the storm as it passes away2 how the wind increases in velocity as it spirally gyrates about the center and approaches nearer and nearer the region where it must ascend2 how the higher layers of air move spirally away from the center and thus cause an accumulation of air about and over the outer periphery of the ,low1 which in turn presses downward and impels the surface air inward4 ,this whole complex system of motion moves eastward4 ,think of the sun drifting in space1 while at the same time each of the planets maintains its respective orbit1 and it will help one to visualize the phenomena of a migrating cyclone or anti-cyclone4 ,illustration3 ,,chart #d4--,,winter ,,storm1 ,,december #ae1 #ahic1 #h ,p4,m4 ,black lines connect places having equal barometric pressure2 red lines connect places having equal temperature2 arrows point in direction wind is blowing2 figures at end of arrows show wind velocity when it is more than light4 clear2 partly cloudy2 cloudy2 ,r rain2 ,s snow4 ,,high indicates center of anti-cyclone1 or high-pressure area2 ,,low indicates center of cyclone1 or low-pressure area4 ,large figures show average temperature in each quadrant of cyclone4 ,shading shows precipitation area of last #bd hours4 ,chart #d1 constructed from observations taken twelve hours later1 shows that the ,low has moved from central ,iowa since #h ,a4,m41 and is now1 at #h ,p4,m41 central over the southern point of ,lake ,michigan4 ,the shaded portion of the chart shows that rain has fallen during the past twelve hours throughout nearly the entire region covered by the cyclone4 ,this was due to the mixing of the air as the storm progressed1 to the cooling by expansion as the air ascended1 to the more rapid rotation about the storm center1 because of the further lowering of the barometer at the center of the disturbance since the preceding chart was made1 and especially to the more humid air encountered as the storm moved eastward and came nearer to the supply of moist winds1--the ,atlantic ,ocean4 ,illustration3 ,,chart #e4--,,winter ,,storm1 ,,december #af1 #ahic1 #h ,a4,m4 ,black lines connect places having equal barometric pressure2 red lines connect places having equal temperature2 arrows point in direction wind is blowing2 figures at end of arrows show wind velocity1 when it is more than light4 clear2 partly cloudy2 cloudy2 ,r rain2 ,s snow4 ,,high indicates center of anti-cyclone1 or high-pressure area2 ,,low indicates center of cyclone1 or low-pressure area4 ,large figures show average temperature in each quadrant of cyclone4 ,shading shows precipitation area of last #bd hours4 ,on ,chart #e a line of arrows extends from the storm center westward to ,wyoming1 where the storm originated4 ,a small cross inclosed by a circle marks its western extremity4 ,another cross located near ,cheyenne shows where the storm center was located twelve hours after its origin4 ,a third cross gives it location near ,des ,moines twenty-four hours after it started eastward4 ,it was here that we began the study of this storm on ,chart #c4 ,a cross near ,chicago indicates the distance traveled by the center during the third twelve hours1 and ,chart #e shows its progress during the fourth twelve-hour period4 ,when the storm was central at ,cheyenne the danger warnings for mariners were displayed at all ports of the ,great ,lakes1 as the forecaster knew that in accordance with general laws the storm must move toward the east4 ,when it was centered at ,chicago1 danger warnings were displayed on the ,atlantic coast from ,north ,carolina to ,maine1 as it was known that long before the storm reached the ocean the in-rush of wind toward the storm center would cause a dangerous on-shore gale and the breaking of heavy seas on the shore line4 ,all craft that could be reached with the danger signals made safe in port1 except the great ocean liners1 which are of such strength as to safely withstand almost any storm4 ,a special set of observations ordered by the ,washington office of the ,weather ,bureau from its stations in the region of the storm1 and well in advance of it1 kept the chief forecaster informed as to the progress of the cyclone1 and before the storm center reached the coast the danger signals communicated to mariners the fact that the winds would soon shift to northwest as the center of the disturbance passed out to sea4 ,the reader's attention will now be directed to the red lines on ,chart #e2 they pass through places having the same temperature1 but for simplicity the readings of temperature1 whereby these lines were located1 are omitted from the printed chart4 ,observe the line marked #dj2 it passes across southern ,new ,england to western ,new ,york1 but when it reaches the center of the storm it encounters the cold northwest winds blowing into the storm on its west side and is forced southward to ,texas4 ,charts #c1 #d1 and #e give a graphic history of one severe winter storm4 ,in summer such general storms do not often occur4 ,they are frequent in spring and fall1 but of higher temperature and less severity than in winter4 ,in summer ,lows drift sluggishly across the continent2 the barometer at the center of the cyclone is usually not more than two to four tenths of an inch below the pressure of the ,highs1 and the rain1 instead of falling in a broad sheet1 as shown by the shading of charts #d and #e1 falls in numerous sporadic outbursts1 each of which is but a few square miles in area1 their combined surfaces usually covering only a part of the region over which passes the ,low4 ,cold ,waves and the ,speed of ,storm ,movement4 ,highs and ,lows drift across the continent from the west towards the east at the average rate of about six hundred miles per day1 or about thirty-seven miles per hour in winter and twenty-two miles in summer1 the first at about the rate of an express train1 and the second approximating the speed of a freight4 ,the ,highs are attended by dry1 cool1 and settled weather4 ,by a vortical action at their centers they draw down the cold air from great altitudes above the clouds4 ,in winter1 when vortical action is vigorous1 they may reach upward to an altitude of seven miles4 ,air starting downward from this region has a temperature of some #gj below zero4 ,we know this from the records secured by sending aloft free balloons carrying automatic thermometers4 7,chapters ,,ii and ,,iii47 ,this air heats by compression because in its downward movement it is continually leaving more and more air above it to exercise pressure upon it4 ,it gains about twenty degrees with each mile of descent1 and if there were no other factors to the problem it would be hot air when it reached the surface of the earth instead of cold air4 ,but early in its descent it gains such heat as to melt and evaporate the ice spicul floating at the height of the fleecy cirrus clouds2 then it evaporates and clears away the moist clouds lower down and finally creates such diathermancy 7the capacity to transmit heat without absorption2 see ,chapter ,v7 that the heat lost by radiation to a clear sky causes what we call a 8cold wave01 and this notwithstanding the heat of compression4 ,the forecaster first observes a cold wave in the northern ,rocky ,mountain region1 in the form of an intense ,high4 ,it will travel southeastward to the center of the continent1 and often to the ,gulf if it is preceded by an active ,low that is located on a low latitude1 as the latter will draw southward the frosty air of the ,high2 after that the course of the storm will be more nearly eastward4 ,now it is of rare occurrence that a cold wave gains entrance to any considerable area of our territory without warning1 but in the early days of the ,weather ,bureau they too often reach ,iowa1 or ,states farther east1 without any notice whatever4 ,it was then discovered that a certain type of weather map preceded such failures of the forecaster4 ,one who is interested in gaining early knowledge of the approach of a cold wave to the ,united ,states should watch not only for the appearance of abnormally high barometer readings1 from the stations of the ,canadian ,northwest1 or from ,montana and ,north ,dakota1 but especially for a crescent-shaped ,low1 with one horn of the crescent touching ,lake ,superior and the other extending into the middle ,rocky ,mountain region1 at about ,colorado4 ,this ,low will appear to be an innocent affair2 there may be a small secondary ,low in each end of the crescent1 and no ,high of any importance in the northwest1 for which one ordinarily would look in anticipating a cold wave4 ,but when this crescent-shaped ,low appears on the morning weather map1 a ,high of marked intensity invariably will develop with great suddenness over ,montana and ,north ,dakota and bring a cold wave to the ,middle ,mississippi ,valley before the next morning1 if the time of year be winter4 ,do not forget that the ,low is as important as the ,high in causing a cold wave1 for the ,high that brings the cold air must follow in the track of the ,low and will be attracted by the latter in proportion to its lowness1 as indicated by the isobar inclosing the center of the ,low4 ,a cold wave will reach the ,gulf only if the preceding ,low originate in ,texas2 it will be confined to the ,ohio ,valley as the limit of its southern influence if the preceding ,low originate in ,colorado2 and it will only skirt the northern border of the ,united ,states and the ,lake region if the ,low begin in ,montana4 ,more and more is man applying science to commerce and industry4 ,when the weather map1 which was unknown but little more than half a century ago1 indicates the formation of a heavy body of cold air in the extreme northwest1 the chief official forecaster at ,washington is on the alert2 he orders special observations every few hours from the ,weather ,bureau stations directly within and well in advance of the cold area1 and as soon as he becomes satisfied that a cold wave is on its way1 the previously arranged system of disseminating warnings is brought into action1 and by telegraph1 telephone1 flags1 whistles1 bulletins1 and other agencies1 the people in every city1 town and hamlet1 and many in the stock and farming regions1 are notified of the advancing cold twelve to twenty-four hours before it reaches them4 ,illustration3 ,,chart #f4--;,,cold ,,wave ,,zones1 ,,march ,,to ,,november4 ,,amount ,,of ,,fall ,,and ,,verifying ,,limit4 ,charts #f and #g show how the ,weather ,bureau defines a cold wave4 ,there must be a fall of sixteen degrees1 eighteen degrees1 or twenty degrees within thirty-six hours and a certain degree of coldness must be reached4 ,the charts show that what is a cold wave in the ,gulf region is far from one in the northwest4 ,illustration3 ,,chart #g4--;,,cold ,,wave ,,zones1 ,,december1 ,,january1 ,,and ,,february4 ,,amount ,,of ,,fall ,,and ,,verifying ,,limit4 ,illustration3 ,,chart #h4--,,lowest ,,temperatures ,,in ,,the ,,united ,,states1 #ahga-aiac4 ,chart #h shows the lowest temperatures experienced in the ,united ,states since the founding of the ,weather ,bureau1 #ahga to #aiac4 ,note the influence of the ,pacific ,ocean in forcing the zero line from ,arizona northward to ,british ,columbia4 ,illustration3 ,,chart #i4--,,number ,,of ,,cold ,,waves1 #aijd-aiad1 ,,inclusive4 ,chart #i shows the number of times that a cold wave occurred at each station of the ,weather ,bureau for a period of ten years4 ,the number is greater for northern ,new ,england than for the ,red ,river of the ,north ,valley1 because practically all the cold waves that cross ,minnesota reach ,new ,england2 and the latter also receives fierce boreal visitors that come to it from the ,hudson ,bay region lying directly northeast1 which do not visit any portion of ,minnesota or the region farther west4 ,during the period not a single technical cold wave occurred at the coast stations of ,california1 ,oregon1 or ,washington1 while ,red ,bluff and ,sacramento were the only two places in ,california west of the ,sierras1 and ,roseburg1 ,oregon1 the only station west of the ,cascade ,range that had any1 the numbers being one1 two1 and five respectively4 ,in the ,florida peninsula south of ,jacksonville1 ,tampa had two1 while none occurred at ,miami4 ,sometimes the temperature falls lower than that required for a cold wave1 but not within the period of twenty-four hours required by the regulations4 ,a notable case in point is the severe cold wave in ,california in ,january1 #aiac1 the lowest temperature ever observed being recorded at ,san ,diego on the #gth1 when the minimum fell to #be4 ,cold ,waves ,tempered by ,great ,lakes4 ,the severity of cold waves is markedly modified by the ,great ,lakes1 especially in the fall and the first part of winter1 before much of the water surface is covered with ice and snow4 ,not only is the number of cold waves much less at stations of the ,lakes than at near-by places in the interior1 but there is a marked variation in the number that occur at the ,lake stations1 depending upon which side of the lake and how close to the water the station is located4 ,the most striking differences are noted in the ,lake ,michigan region1 the number on the west shore being five or six times as great as on the east side4 ,milwaukee shows a count of forty-seven as compared with nine at ,grand ,haven4 ,this lake influence affects the entire ,lower ,michigan peninsula1 but it is not so great in the interior and eastern sections as along the west shore1 ,grand ,haven's nine standing out against fourteen1 fifteen1 and twenty-three for ,grand ,rapids1 ,detroit1 and ,port ,huron4 ,a similar condition is noted in ,new ,york ,state2 ,buffalo1 ,rochester1 and ,oswego1 near the lake shore1 had twenty1 twenty-seven1 and twenty-nine cold waves respectively1 while the interior stations of ,ithaca1 ,binghamton1 and ,syracuse had thirty-eight1 forty-five1 and fifty-two4 ,cold ,waves ,tempered by the ,heat of ,cities4 ,another reason for the lack of uniformity in the recorded number of cold waves in the various sections of the country is the difference between city and suburban temperatures4 ,stations located in small villages or in the open land will show a greater number of recorded cold waves than those located in large cities1 where the heat stored up by pavements and brick buildings during sunshine each day1 and where the heat from thousands of chimneys1 and maybe millions of human beings1 holds the minimum temperature of night much above that of the free air in the open country4 ,charles ,city1 where the instruments have open country exposure had sixty-five cold waves1 which far exceeds the number recorded at any other station in ,iowa4 ,no matter how severe may be the cold wave that appears in the northwest1 it will not extend over ,wyoming1 ,colorado1 ,utah1 and any region south of them1 unless the center of the ,high extends well over the ,rocky ,mountain ,divide4 ,otherwise it will come down the east slope of the mountains and the cold will not cross them4 ,in the ,lows the conditions of the air and its movements are exactly the reverse of what they are in the ,highs2 the air is warmer and moister1 it is drawn spirally inward from all directions instead of being forced outward as in the ,high1 and it ascends as it approaches the center of depression1 sometimes causing rain or snow as it cools by expansion during its ascent4 ,while the air cools with ascent in the ,low at the same rate that it warms with descent in the ,high1 the earth experiences a general warming effect with the passage of the ,lows1 because the air falls but little in temperature as it rises before it reaches its dew point1 and then there is a liberation of the latent heat of condensation 7see ,chapter ,v72 and what is more important1 there is formed a covering of clouds that checks or wholly stops radiation outward from the lower air4 ,however there are times when the passage of ,lows produces a cooling effect4 ,this is when abnormally hot weather has prevailed for some days2 then the air may be mixed1 washed1 and cooled by thunder-showers4 ,illustration3 ,,chart #aj4--,,storm ,,tracks ,,for ,,august ,,for ,,ten ,,years4 ,highs and ,lows alternately drift across the continent in periods of about three days each4 ,they are a part of the divine economy that provides for the seedtime and the harvest1 for1 as previously stated1 the ,lows draw the warm1 vapor-bearing currents inland from the ,gulf and the ocean and cause them to deposit their moisture far to the north and west4 ,four sevenths of all our storms come from the middle or the north plateau regions of the ,rocky ,mountains1 or at least enter our field of observation from those regions1 and pass from this arid or sub-arid section of the continent easterly over the ,lakes and ,new ,england1 producing but little rainfall4 ,the greater part of the remaining three sevenths are first observed in the arid regions of our southwestern ,states2 they always move northeastward and can be depended on to give bountiful rainfall so soon as or a little before they reach the ,mississippi ,river4 ,some of them cross the ,atlantic and affect the continent of ,europe4 ,charts #aj and #aa show the courses of storms in this country1 and where they originate1 or are first brought under the survey of our system of observation4 ,illustration3 ,,chart #aa4--,,storm ,,tracks ,,for ,,february ,,for ,,ten ,,years4 ,west ,indian ,hurricanes4 ,a few of the most severe storms that touch any portion of our continent originate in the ,west ,indies and travel in a northwesterly direction until they touch our ,gulf or ,south ,atlantic coast1 when1 passing from the influence of the northeast trade winds which carried them westward1 they recurve and pass along our eastern coast1 usually with their centers offshore and following the ,gulf ,stream4 ,these violent atmospheric convulsions are usually detected in the process of formation through the effectiveness of the storm-warning service established by the writer during the ,spanish-,american ,war1 under the direction of the ,president1 for the purpose of giving warning to our fleet before the coming of a hurricane4 ,the ,president realized the great part played by storms in many of the naval battles of the past1 and it may be surmised that he was more afraid of a ,west ,indian hurricane than he was of the ,spanish ,navy4 ,but ,cervera was beaten and the blockade was raised before the hurricanes of #ahih began4 ,galveston ,hurricane4 ,the new ,weather ,service1 with a cordon of stations down the ,windward ,islands and along the north coast of ,south ,america1 surrounding our fleet1 and inaugurated as a war measure1 so demonstrated its value in locating and giving warning of the coming of a hurricane soon after the end of the war that ,congress continued it as a permanent instrument of peace2 and when the destructive ,galveston ,hurricane occurred in #aijj it detected the storm at its inception and so fully advised shipping of the storm's movements that not a vessel was lost as the storm roared and gyrated across the ,gulf of ,mexico and crashed upon the ,texas coast1 destroying a large part of the city and drowning six thousand people4 ,the hurricane is simply a rapidly gyrating cyclone2 it usually is only one to three hundred miles in diameter4 ,the storm that destroyed ,galveston moved across the ,caribbean ,sea at the rate of only about eight to ten miles an hour4 ,it increased its rate as it moved northward1 crossing the ,gulf at about fifteen miles per hour4 ,the speed of translation was so slow and the velocity of gyration so rapid that immense swells were propagated outward from the center of the storm2 they reached the ,texas coast some sixteen hours before the storm itself reached ,galveston4 ,as it moved northward to ,iowa its velocity of translation increased and its rate of gyration decreased1 so that it crossed the ,lakes with both movements at about sixty miles per hour4 ,at ,galveston the anemometer blew to pieces after recording one hundred and thirty miles per hour4 ,danger to ,atlantic ,coast ,summer ,resorts4 ,the writer frequently has been asked as to the possibilities of a populous ,atlantic coast resort being submerged by the waters driven inshore by a hurricane1 or being lifted up in the center of the storm as the result of decreased air pressure inside the cyclonic whirl4 ,the answer is that such a catastrophe is possible to any ,atlantic coast city 7more especially those south of ,norfolk7 that is not protected by a heavy breakwater of ten to twenty feet above sea level1 and whose building foundations and walls are not of brick or concrete for at least ten feet above the water level4 ,it would be necessary for a ,west ,indian hurricane of unusual intensity--one similar to that which wrecked ,galveston--to be considerably deflected westward out of its normal track in order to hit one of our coast cities north of ,chesapeake ,bay so that the center of the storm would pass over it1 or near enough to cause destruction4 ,in ,galveston there was little damage to strongly constructed buildings of brick or stone4 ,the ,breaking of ,droughts4 ,it is most important for the forecaster to know when and how droughts may be broken4 ,he will observe that when the great cereal plains are famishing for moisture the ,lows all originate on the middle or north ,rocky ,mountain plateau1 in the region of ,colorado or ,montana1 and that the drought continues until the ,lows begin to form in the extreme southwest--in ,arizona1 ,new ,mexico1 or ,texas4 ,as previously stated such ,lows always bring rain as they move northeastward4 ,warm ,waves4 ,there come in summer periods of almost stagnation in the drift of the ,highs and the ,lows across the continent4 ,at such times if a ,high be centered in the ,south ,atlantic ,ocean1 with its center at ,bermuda1 and its western limits extending into the ,south ,atlantic coast ,states1 there will result what is popularly known as a warm wave1 for the air will slowly and steadily move from the southeast1 where the pressure is greater1 towards the northwest1 where it is less2 it will receive constant accretions of heat from the radiating surface of the earth1 and finally attain to a temperature that is extremely uncomfortable to all forms of life1 that lowers the physical stamina1 and that largely increases the death rate4 ,this superheated condition of the lower stratum of air in which we live continues until a ,low develops in the southwest and a ,high in the northwest1 which relation1 as we already know1 soon brings rainfall to the interior of the country4 ,v-shaped ,lows are reasonably sure to cause precipitation1 and if the barometer at the center of the ,low be five to seven tenths below the outer limits of the depression1 heavy precipitation and destructive local storms may be expected4 ,thunderstorms4 ,the thunderstorm is caused by cold and heavy air from above breaking through into a lighter and superheated stratum next the earth4 ,some of them have a horizontal rolling motion which throws forward the cool air in the direction in which the storm is moving4 ,it seldom is more than five or ten miles in width and twenty to thirty miles in length4 ,in general1 thunderstorms move from the west toward some eastern point1 more often southwest to northeast4 ,the frequency of thunderstorms is the greatest with ill-defined ,lows whose pressure is but little below the normal air pressure of thirty inches4 ,any depression of the barometer slightly below the level at surrounding stations--such as occurs when a weak ,high of only thirty inches1 or thirty and one tenth inches1 breaks up into two or more areas1 with slightly lower pressure between them--is fruitful of thunderstorms4 ,a ,high of but modest intensity advancing eastward into a region of slightly lower pressure and much higher temperature causes thunderstorms along its eastern front4 ,a temperature of #hj on the morning weather map1 with a high humidity1 seldom can endure beyond the second day without a break and the coming of cooling thunder-showers4 ,any ,low with abnormal heat and humidity in its southeast quadrant is usually attended with numerous thunder squalls in the regions of high temperature and moisture4 ,of the thunderstorm days in the ,united ,states few occur in the ,rocky ,mountain regions or in northern ,new ,england4 ,the greatest number is in ,florida and the ,gulf ,states and thence northward up the ,mississippi ,valley4 ,the ,moon ,has ,no ,influence on the ,weather4 ,the moon used to be the farmer's most valued friend as a forecaster of the weather and as a guide in the planting of crops1 but a higher order of intelligence is causing this fallacy to pass away4 ,the moon's nearness to the earth and the fact that its phases occur in about seven days1 which is about twice the period of storm recurrence1 in the minds of many have endowed it with potency in the influencing of our weather4 ,rain may occur on the same day of the week for several weeks in succession1 but only occasionally1 while the moon is constantly progressing from one phase to another4 ,the few cases that prove the mistaken theory are taken as proof conclusive1 while the many cases that do not prove acceptable to the moon forecaster are ignored and not mentioned to his friends nor even acknowledged to himself4 ,one is reluctant to have a belief disproved1 no matter how ridiculous it may be4 ,in fact1 the more untenable it is1 the more tenaciously some adhere to it1 as though they were loyally standing by an old friend who had made mistakes1 but who still was good at heart4 ,the attraction of the moon1 because of its nearness and notwithstanding its small mass1 is far more potent in the raising of the tides of the ocean than is the sun1 but its attraction on our atmosphere produces a tide of only four thousandths of an inch of the barometer1 an influence that is shadowy and without the least influence in causing storms1 or changes of any kind in the weather2 and there is no possible way in which the moon could influence the germination of seed or the growing of crops4 ,equinoctial ,storm4 ,as the summer wanes the ,lows become more pronounced and the sporadic showers give place to general rain storms along in ,september4 ,there is no objection to these storms being known as 8,equinoctial01 except that any date in the latter half of ,september is as liable to show a beginning of these storms as is the #bast or the #bb;d4 ,the equinox simply marks the middle period in the transition from one type of weather to another4 ,forecasting from ,halos4 ,the halos that sometimes surround the sun or the moon indicate the coming of precipitation to the extent of making manifest the presence in the upper air of large quantities of vapor of water in a congealed state4 ,when the vapor of water cools quietly in the laboratory it frequently forms minute spheres of water1 which1 strange to relate1 may remain liquid all the way down to zero and below2 but if touched or jostled they instantly turn to ice1 in the form of spicul1 or needles2 they are simply hexagonal slender prisms capped by hexagonal pyramids4 ,these needles rotate or spin about as they fall4 ,the geometrical relations of the facets of the crystals to the axis of rotation and to the line along which they fall are a complex problem in optics4 ,suffice to say that the observer1 looking through a filmy cloud of such crystals1 would see in one part of the sky a halo1 in another part an arc of light1 and in other directions bright spots like the sun1 all of them arranged symmetrically with regard to the sun and the observer's zenith4 ,a lunar halo is a large ring concentric about the moon4 ,a secondary halo surrounds the first4 ,mock suns or mock moons may appear coincident with solar or lunar halos4 ,the ice prisms through which one sees the phenomena both refract and diffract the light as it passes through the cloud and by partly decomposing the rays render visible a part of their elementary colors4 ,the red is on the inside1 next to which is a little yellow or green1 with bluish white on the outside4 ,in coronas1 which are much smaller1 the red is on the outside4 ,a detailed description of these phenomena may be found in ,moore's 8,descriptive ,meteorology0 7,appleton74 ,tornadoes4 ,the cyclone has a diameter of a thousand to two thousand miles1 the hurricane about one to three hundred and the tornado only one to ten hundred feet4 ,the hurricane is much more destructive than the cyclone1 and the tornado is incomparably greater in velocity of gyration and rending force than the hurricane4 ,new ,england1 ,florida1 and the wide region including the eastern slope of the ,rocky ,mountains westward to the ,pacific are nearly free from the atmospheric convulsions that cause the tornadoes1 and they are infrequent in any ,atlantic coast ,state1 but numerous in the ,states bordering on the ,mississippi ,river1 and in the eastern halves of ,oklahoma1 ,kansas1 and ,nebraska4 ,during a year of great frequency of tornadoes1 about ninety storms occurred1 while during some other years the number has been as low as twenty4 ,the direction generally is toward the northeast4 ,the average rate of movement of the tornado cloud is about twenty-five miles per hour and the width of its destructive path only five hundred to one thousand feet2 the time of passage is less than half a minute4 ,it does not come upon one unseen and unheralded4 ,many times the advancing funnel-shaped clouds may be seen1 and they always are accompanied by a great roar which may be heard for miles4 ,except a tornado cellar1 the cellar of a frame house is the safest place4 ,the writer has examined either the wrecks or the records of hundreds of tornadoes and does not know of a single case of a person being killed by a tornado in the cellar of a frame house4 ,if one is in the open and a tornado approaches1 never flee to the north or to the east1 but rather to the northwest1 and one needs to travel but a short distance to pass out of the track of the monster4 ,the tornado always twists counter clockwise1 the same as the cyclone in whose southeast quadrant it nearly always occurs4 ,on the southeast side of the path there are indrafts2 so that it is safer1 unless the track of the oncoming storm is clearly seen to be well to the north of the observer1 for one to run toward the northwest4 ,persons have stood near to the north side of a tornado track during its passage without suffering injury4 ,if a cave1 the cellar of a frame house1 or a narrow ditch cannot be reached1 the best thing to do is to lie flat on the ground as far from buildings and trees as possible4 ,the tornado is essentially an ,american storm1 doubtless caused by the running together1 in the southeast quadrant of a cyclone1 of cold northwest currents and warm winds from the southeast1 at a time when the latter are saturated with moisture4 ,they are confined almost entirely to the region between the two great mountain systems of the continent1 none occurring in the ,rocky ,mountains and but few east of the ,alleghanies4 ,the north and south trend of our mountain systems1 quite different from the systems of ,europe and ,asia1 facilitates the coming together of conflicting winds of widely different temperatures in the lower reaches of the atmosphere where there is an abundance of water vapor2 no tornadic whirls probably can occur without an abundance of water vapor and the energizing effect of the heat liberated in the whirling cloud as this vapor is suddenly carried aloft and liberated by condensation right in the center of the disturbance4 ,because of the relation of the trend of its great mountain systems to its oceans1 the ,united ,states occupies a somewhat unique position meteorologically in the world4 ,its atmospheric conditions are more active than those of any other continent1 which conditions are beneficial to the people of this country4 ,when to ,watch the ,weather ,map for ,tornadoes4 ,the four conditions essential to the formation of tornadoes are as follows3 #a4 ,a cyclone1 the center of which is to the north or northwest2 #b4 ,an isotherm of #gj or over extending from the southeast well up into the center of the cyclone1 and then passing outward toward the southwest1 all inside the southeast quadrant of the ,low2 #c4 ,excessive humidity2 #d4 ,time of year ,march #ae to ,june #ae4 ,illustration3 ,,fig4 #ag4--,,tornado ,,cloud4 ,if any one of the four foregoing conditions be absent1 tornadoes are not liable to occur4 ,the reason why spring and early summer is the time when tornadoes are most frequent is because the earth and a thin stratum of air immediately next the earth are heated up rapidly with the gaining heat of the sun's rays in the spring1 while the air a short distance aloft still retains much of the cold of winter4 ,at this time cyclonic action may bring together air masses of widely different temperatures1 especially when the upper layers on the west side of the ,low are drawn down and commingled with the hot and humid surface winds of the southeast quadrant4 ,tornadoes ,not ,increasing4 ,the writer does not indorse the theory that the number of these storms is increasing2 that the breaking of the virgin soil of the prairie1 the planting or the cutting away of the forests1 the drainage of land surfaces by tiles1 the stringing of thousands of miles of wire1 or the laying of iron and steel rails have materially altered the climate or contributed to the frequency or the intensity of storms4 ,to be sure1 as population becomes more dense greater destruction will ensue with the same number of storms4 ,difficult to ,forecast ,tornadoes4 ,it is not possible for the forecaster to warn the exact cities and towns that will be struck by tornadoes without unduly alarming many places that will wholly escape injury4 ,what we know is that tornadoes are almost wholly confined to the southeast quadrant of a cyclone1 and that when the thermal1 hygrometric1 and time conditions are favorable1 a region about one or two hundred miles square will be sacrificed by a number of these atmospheric twisters4 ,one of the most destructive tornadoes of record devastated ,st4 ,louis in the afternoon of ,may #bg1 #ahif4 ,the abnormal heat and humidity of a rather small and weak cyclone centered in eastern ,kansas on the morning weather map of that day1 caused the ,weather ,bureau to distribute tornado forecasts at #aj ,a4,m4 throughout all of ,missouri4 ,the schools of ,st4 ,louis were dismissed and the children sent home on receipt of the warning1 and although some eight or ten separate tornadoes touched various parts of the ,state and the people were prepared for their coming1 so many people were terrorized by the warning in communities that were not harmed1 that the writer1 then ,chief of the ,weather ,bureau1 at once issued orders forbidding the specific forecasting of tornadoes in the future4 ,under tornadic conditions the forecast is for 8conditions favorable for severe local storms40 ,freaks of the ,tornado4 ,the writer was in ,st4 ,louis the day after the storm and spent much time in examining the wreckage4 ,he was impressed with the fact that some buildings were burst outward and that all four walls fell away from their bases1 indicating that the tornado cloud must have lifted and dropped down over them in such a way that the partial vacuum that is created by the rotating cloud through centrifugal force so reduced the pressure of the air on the outside of the houses that the normal pressure of fifteen pounds per square inch exploded them4 ,he saw bricks in a plastered wall that were neatly cleaned of all plaster by the expansion of the air inside the brick1 as the air pressure from the outside was reduced4 ,he saw a two by four pine scantling shot through five eighths of solid iron on the ,eads ,bridge1 the pine stick protruding several feet through the iron side of the roadway1 exemplifying the old principle of shooting a candle through a board4 ,he saw a six by eight piece of timber driven four feet almost straight down into the hard compact soil1 a gardener's spade shot six inches into the tough body of a tree1 a chip driven through the limb of a tree1 and wheat straws forced into the body of a tree to the depth of over half an inch4 ,such was the fearful velocity of the wind as it gyrated about the small center of the tornado1--a velocity exceeding that of any rifle bullet4 7,see ,figures #ag1 #ah1 #ai1 and #bj47 ,illustration3 ,,fig4 #ah4--,,the ,,st4 ,,louis ,,tornado ,,of ,,may #bg1 #ahif1 ,,shot ,a ,,pine ,,scantling ,,through ,,the ,,iron ,,side ,,of ,,the ,,eads ,,bridge4 ,illustration3 ,,fig4 #ai4--,,the ,,st4 ,,louis ,,tornado ,,of ,,may #bg1 #ahif1 ,,shot ,a ,,shovel ,,six ,,inches ,,into ,,the ,,body ,,of ,a ,,tree4 ,some have advocated the planting of trees to the southwest of cities in the regions where tornadoes are frequent1 so that the tornadoes may expend their energy in uprooting the trees before they come to the city1 but this storm traveled through several miles of brick buildings1 razing them to the ground and almost pulverizing them and still left the city apparently with greater force than it had on entering4 ,the largest trees would offer no more resistance to a tornado cloud than would so many blades of grass4 ,when the official forecasts contain the statement that conditions are favorable for 8severe local storms0 it would be well to carefully observe the formation of portentous clouds in the west and southwest1 between #c and #f o'clock in the afternoon1 and if one with black1 ragged fringes on its lower edge and accompanied with a noise like several railroad trains makes its appearance1 seek safety in the cellar of a frame house4 ,illustration3 ,,fig4 #bj4--,,the ,,st4 ,,louis ,,tornado ,,drove ,,straws ,,one ,,half ,,inch ,,into ,,wood4 ,general ,rules for ,forecastings4 ,what has gone before in this chapter gives an idea of what guides the weather forecaster in making his deductions4 ,in brief1 he studies the developments and the movements of the ,highs and the ,lows during the past two or three days1 as shown by preceding weather maps1 and from the knowledge gained forecasts the future course and intensity of the fair and the foul weather areas for one1 two1 or three days in advance4 ,by preserving the weather map each day and noting the movements of the ,highs and the ,lows1 any intelligent person can make a fairly accurate forecast for himself1 always remembering that the ,lows1 as they drift towards him1 will bring warmer weather and sometimes rain or snow1 and that as they pass his place of observation the ,highs following in the tracks of the ,lows will bring cooler and fair weather1 except during periods of extreme summer heat1 when the ,lows bring showers that cool the parched earth2 and except in the north ,rocky ,mountain plateau1 where most of the precipitation occurs after the center of the ,low has passed and northwest winds are blowing4 ,the amateur weather forecaster can closely anticipate the temperature of his region by remembering that the weather will be cool and the humidity low so long as the center of the predominating ,high 7the ,high inclosing the greatest area within the thirty-inch isobar7 is north of his latitude1 either northeast or northwest1 and that it will be warm so long as the ,high is south of the parallel of latitude that passes through his section of country4 ,he will find that the centers of the ,lows will follow closely the direction indicated by the isotherms that lead eastward out of their centers1 and that they move across the country from the west in quite regular succession1 and that the frequent changes from sunshine to clouds and from warm to cold are the result of the mixing of the air by these atmospheric eddies4 ,experience will teach him that ,lows from the southwest are reasonably sure of causing precipitation1 and that if his temperature be sufficiently low--anywhere from zero to #bj--the fall will be in the shape of snow2 that ,lows that only skirt our northern border will be deficient in precipitation1 even if they cause any at all2 that the slow settling of a ,high over the ,south ,atlantic ,states means heat for all the rest of the country east of the ,rocky ,mountains in degree that will be dependent upon the magnitude and the intensity of the southern ,high2 that the heat will continue1 even if temporarily interrupted by showers1 so long as this ,high retains its location in the southeast2 that tornadoes occur in the spring of the year when ,lows have excessive heat and humidity in their southeast quadrants2 that ,v-shaped ,lows cause violent local storms1 if not tornadoes1 and often deluges of rain2 and that frosts may be expected in the country when a minimum temperature of #dj is forecast for the city2 and that the severity of cold waves modifies as they come eastward1 and that they will only flow as far south as the area covered by the ,low that preceded them1--that is to say1 by that part of the ,low included in the thirty-inch isobar1 or by a close approximation to such area4 ,national ,forecaster ,e4 ,h4 ,bowie1 known to the writer as one of the ablest forecasters ever developed by the ,weather ,bureau1 in a recent most valuable publication by the ,bureau1 entitled 8,weather ,forecasting in the ,united ,states01 formulates rules for forecasting as follows3 #a4 ,when there is an area of high pressure over the southeast and a cold wave in the northwest threatens1 there will be a storm development in the southwest and precipitation will be general4 #b4 ,if a storm form in the southwest and be forced to the left of a normal track 7,charts #aj and #aa71 another storm will immediately begin to develop in the southwest and it becomes a sure rain producer4 ,storms that develop in the southwest and move normally are quickly followed by clearing weather4 #c4 ,troughs of low pressure moving from the west are of two types--the narrow and the wide4 ,the former moves eastward slowly and storm centers develop in the extreme northern and the extreme southern ends4 ,when the trough is wide1 the development of an extensive storm area is not uncommon1 especially if the wide intervening area between the ,highs shows relatively high temperatures4 #d4 ,when the northern end of a trough moves eastward faster than the southern end1 the weather conditions in the south and southwest remain unsettled and the chances are that a storm will form southwest of the ,high that follows4 ,when the southern end moves faster than the northern end1 settled weather follows4 #e4 ,storms that start in the northwest and move southeastward do not gather great intensity until they begin to recurve to the northward4 ,at the time of recurving they move slowly1 as a rule1 and care must be exercised in predicting clearing weather4 #f4 ,marked changes in temperature in the southeast and northwest quadrants imply an increase in the storm's intensity4 ,small temperature changes do not indicate a further development of the storm4 #g4 ,abnormally high temperatures northwest of a storm indicate that it will either retrograde or remain stationary4 #h4 ,east of the ,rocky ,mountains1 a storm which moves to the left of its normal track increases in intensity4 #i4 ,storms with isobars closely crowded on the west and northwest generally move slowly and to the east or southeast1 and the precipitation and high winds are maintained unusually long in the northern and western quadrants4 #aj4 ,storms with the isobars closely crowded in the south and southeast quadrants move rapidly northeastward and the weather quickly clears after the passage of the storm center4 ,rules for ,making ,local ,forecasts4 ,as an illustration of what may be done by the local observer or the layman in formulating rules of weather forecasting for his immediate vicinities1 the following rules1 which were evolved by the writer in #ahib1 while serving as the ,weather ,bureau local forecaster for ,milwaukee1 ,wisconsin1 are subjoined3 #a4 ,in summer warmer weather occurs after the center of the ,low has passed a little to the east1 and southwest winds are blowing1 because the easterly winds1 which otherwise would be the warmest winds1 are cooled by passing over the lake4 #b4 ,a ,low from the northwest that reaches western ,minnesota and western ,iowa without precipitation or clouds will pass over ,wisconsin as a dry ,low1 unless the isobars are closer than five eighths of an inch4 #c4 ,light frosts will occur on clear1 quiet nights in the cranberry marshes when minimum temperatures at ,duluth and ,la ,crosse fall to #dj and #de respectively4 ,when these stations record five degrees lower the frost will be killing in the cranberry marshes and light in the tobacco fields of the southern counties of the ,state4 #d4 ,no frost will occur in the counties bordering on ,lake ,michigan until the temperatures at the ,weather ,bureau stations fall close to the freezing point1 such is the influence of the lake in storing up heat and slowly radiating it during the night2 and on the eastern side of the lake its protecting influence is much greater4 #e4 ,when the wind sets in from points between south and southeast and the barometer falls steadily1 a storm is approaching from the west or northwest1 and its center will pass near or north of the observer within twelve to twenty-four hours1 with wind shifting to northwest by way of south and southwest4 ,when the wind sets in from points between east and northeast and the barometer falls steadily1 a storm is approaching from the south or southwest1 and its center will pass near or to the south of the observer within twelve to twenty-four hours1 with wind shifting to northwest by way of north4 ,the rapidity of the storm's approach and its intensity will be indicated by the rate and the amount of the fall in the barometer4 ,vast ,extent of the ,area ,brought ,under ,observation4 ,it is a wonderful panoramic picture of atmospheric conditions which1 by the aid of the electro-magnetic telegraph and two hundred simultaneously reporting stations1 is presented to the eye of the forecaster4 ,each day the kaleidoscope changes and a new graphic picture comes into view4 ,nowhere else in the world can the student of the weather find such opportunities4 ,early meteorologists studied only the storm of low levels and humid airs1 where convection only needed to carry the moist air currents to but a slightly higher elevation before cooling by expansion would produce condensation and an immediate acceleration of the cyclone by the liberation of latent heat within the region of the upward-moving air in its central area4 ,they never had seen the cyclones of the arid northern ,rocky ,mountain plateau move down to our ,great ,lakes with rapidly increasing energy1 notwithstanding the fact that there had been little condensation1 and hence no addition of the latent heat that ,espy supposed was essential to a continuation of storms4 ,the widely differing elevation1 topography1 temperature1 and moisture of the broad region under observation by the ,united ,states ,weather ,bureau present conditions unequaled for the study of every phase of storm development and translation1 or at least such as may be comprehended from data taken on the bottom of the atmospheric ocean2 and it is but a matter of a short time when the data for extremely high levels will be added4 ,here we see summer cyclones formed under the intense solar radiation that beats down through a nearly diathermanous atmosphere upon the wastes of the ,rocky ,mountain plateaus2 cyclones that1 if they form in the northern part of the plateau region1 move eastward to our ,lakes and thence eastward to the ,st4 ,lawrence with scant rainfall2 cyclones that1 if they have their origin farther south in the region of ,colorado1 move into the ,ohio ,valley and thence to ,new ,england with considerably more precipitation2 and cyclones that1 if they have their origin anywhere in our southwest ,states or ,texas1 or enter our region of observation from the ,south ,pacific ,ocean1 can always be expected to cause general rainfall when they reach the ,lower ,mississippi ,valley and later as they pass up through the central portions of the continent4 ,here also one may view the great winter cyclones that originate in the ,pacific between ,hawaii and the ,aleutian ,islands and come under our vision as they successfully surmount the formidable barriers of the ,rocky ,mountains with but little diminution of energy1 sweep across our continent with increasing force and heavy precipitation1 and within three days pass beyond our meteorological horizon at the ,atlantic seaboard only to be heard from several days later as boreal ravagers of ,northern ,europe4 ,the great anti-cyclones that constitute the ,american cold waves drift into our territory from ,canadian ,northwest provinces1 and are studied under rapidly changing conditions during three thousand miles of their course4 ,west ,indian hurricanes1 at sea level and in humid air1 which are the most violent of all storms except the ,american tornado1 intrude themselves into the domain covered by the weather map at ,florida or the ,east ,gulf coast and usually pass off to the northeast with high winds skirting our southern coast stations4 ,permanent ,highs and ,lows in the ,pacific ,are ,great ,centers of ,action4 ,near the end of ,chapter ,,xii reference is made to the fact that there is a barrier in the ,pacific ,ocean that interferes with the movement of storms from the ,orient1 but which does not entirely stop their progress4 ,extensive ,highs and ,lows1 sometimes called 8,centers of ,action0 because they do not migrate like the traveling ,highs and ,lows that cause the alternations of weather that we experience from day to day1 are also called ,sub-permanent ,highs and ,lows4 ,they are the parent systems out of which come many of the ,highs and ,lows that cross the ,north ,american continent1 and they act as a bar to the free passage of storms from the ,far ,east4 ,as these ,sub-permanent areas shift their centers a little to the north or to the south they change the character and the line of movement of the storms and cool waves that come to us1 and they alter the general character of the weather for thousands of miles to the east of them4 ,in the region of ,iceland is the center of an extensive ,sub-permanent ,low that has much to do in controlling the weather of ,europe1 and there is a ,sub-permanent ,high central at or near ,bermuda in the southern part of the ,north ,atlantic ,ocean4 ,whenever the latter is built up by having a migrating ,high from the ,north ,american continent join with it1 the whole ,united ,states experiences what is called a 8hot wave01 and the heat continues as long as this ,sub-permanent ,high remains unusually high and extends its western limits to include our ,south ,atlantic ,states4 ,the matter in the foregoing paragraph is so important that it will be restated in slightly different form3 ,whenever either the ,high or the ,low ,center of ,action 7,sub-permanent ,high and ,low71 out of which comes nearly all of the migrating ,highs and ,lows1 shifts its normal seasonal position1 then storms are erratic and unusual weather occurs over the ,north ,american continent and farther eastward4 ,the reason why much the greater number of the storms that cross the ,united ,states1 the ,atlantic ,ocean1 and ,europe originate either in our ,rockies1 the ,canadian ,northwest1 or just off the ,alaskan coast is due to the fact 7,chart #a1 page #ii7 that the ,low center of action is normally over the middle and northern ,rocky ,mountain plateau in summer1 and over the ,aleutian ,islands 7,chart #b1 page #ajj7 in winter4 ,the ,high that follows the migrating ,low in winter either separates from the center of action central over the ,canadian ,rockies 7,chart #b71 or from the one central at ,honolulu2 if from the latter1 the weather will be simply cooler after the passage of the ,low1 but if the ,high separates from the center of action in the ,canadian ,rockies it will constitute a cold wave as it follows a ,low southeastward into the interior of the ,united ,states and then eastward to the coast4 ,,chapter ,x ,,climate ,,change ,,of ,,solar ,,rays ,,into ,,light1 ,,heat1 ,,and ,,other ,,forms ,,of ,,energy ,,as ,,they ,,are ,,absorbed ,,by ,,our ,,atmosphere ,,or ,,as ,,they ,,encounter ,,the ,,earth--,,temperatures ,,of ,,water1 ,,earth1 ,,and ,,air--,,how ,,sanitary ,,homes ,,may ,,be ,,cheaply ,,constructed ,,below ,,ground1 ,,cool ,,in ,,summer ,,and ,,warm ,,in ,,winter ,difference between ,climate and ,weather4 ,one may speak of the weather of to-day or of some time that is past1 but not of the climate of to-day1 or of any day1 month1 or year that is gone3 for the climate of a place is determined by a study of its weather records for a long period of years4 ,climate changes so slowly that we speak of the movement as a mutation rather than as a change4 ,the time that has elapsed since the discovery of the barometer and the thermometer--about two and a half centuries--is so short as to show little if any change in climate1 while the weather changes from day to day4 ,the ,sun ,our ,only ,source of ,appreciable ,heat4 ,each one of the stars visible to the eye and many of the millions that are not visible1 are suns accompanied by planets4 ,their conditions are similar to those of our sun1 except that most of them are larger than our sun1 some a million times larger4 ,but their distance is so great that they exercise little or no influence in the heating of the earth4 ,light travels at about the rate of #ahf1djj miles per second1 and yet these stars are so distant that if the nearest one had been created at the time of the signing of the ,declaration of ,independence we still would be in ignorance of its existence1 for its first rays of light would not reach us for many years yet to come2 and light from some of the remote suns that we call stars requires thousands of years to come4 ,it is apparent therefore that we depend exclusively upon our own luminary for the heat that warms our atmosphere and gives life to the surface of the earth4 ,illustration3 ,,fig4 #ba4--;,equinoxes1 ,march #ba and ,september #bb4 ,axis perpendicular to ,sun's rays4 ,day and night everywhere equal4 ,different ,temperatures with the ,same ,quantity of ,solar ,heat4 ,on the same day of each year at the same place practically the same amount of heat falls upon and into the earth's atmosphere from the sun1 but rarely does the same temperature and weather occur1 and often there is wide variation in the weather of the same day of two different years4 ,the first of ,july may be cold enough to wear an overcoat at midday1 or the first of ,january may be so temperate as to permit the donning of summer habiliments1 while1 according to the amount of heat received from the sun1 there would have occurred the usual seasonal conditions on the days named had there been no other influence than the direct action of the sun's heat4 ,the cause of these seeming inconsistencies is due to the motions of the atmosphere in a stratum only five to seven miles in depth1 air cooling by expansion as it ascends in cyclonic whirls and heating as it descends in anti-cyclonic movements4 ,condensation1 in the form of cloud or rain or snow1 also introduces complications1 usually producing a cooling effect in summer and a warming in winter4 ,in other words3 interference in the uniform and gradual change in temperature1 of the lower stratum of air in which we live1 from the heat of summer to the cold of winter1 and then the reverse process1 is due entirely to the heating and the cooling of the lower air by its upward and downward motions4 ,illustration3 ,,fig4 #bb4--,summer ,solstice1 ,june #ba4 ,north ,pole leans towards ,sun's rays4 ,illustration3 ,,fig4 #bc4--,winter ,solstice1 ,december #ba4 ,north ,pole is dark now instead of light1 as at ,summer ,solstice4 ,pole leans in same direction but ,earth being on opposite side of its orbit rays come from opposite direction4 ,refer to ,figure #bd4 ,if the earth's axis were vertical to the plane of its orbit all places on its surface always would have days of twelve hours each and the nights would be of the same length2 sunshine would just touch both poles 7,figure #ba7 throughout the entire course of the earth around the sun and there would be no seasons4 ,one would need to change one's location on the earth in order to get a change of weather1 which would be monotonous and quite different from the active conditions of the atmosphere that we now enjoy4 ,the whole conditions of life would be altered for the worse4 ,you have seen a top tilt over to one side as it spun on the floor4 ,in the same way the earth spins on its axis as it pursues its course around the sun without changing the direction towards which its axis points1 as shown by ,figure #bd4 ,illustration3 ,,fig4 #bd4--,note that direction of axis does not change as ,earth moves around ,sun4 ,this causes variation in area of surface illuminated4 ,if axis were perpendicular to plane of orbit there would be no seasons4 ,illustration3 ,,fig4 #be4--;,as angle of incidence decreases from #ij to #aj the heat received on upper end of blocks is spread over greater area at bottom1 and its temperature diminished4 7,abbe47 ,the intensity of the sun's rays at sunrise and at sunset is less than at midday because the quantity of heat received at the outer limits of the atmosphere on a given area1 as for instance at the area of the upper ends of the blocks in ,figure #be1 passes through a deeper stratum of air the lower the angle of incidence1 and because it is distributed over a larger area when it reaches the surface of the earth4 ,as the heat of day increases from morning until midday and then decreases1 so does the heat of the year increase from midwinter to midsummer and then decrease1 and for the same reason3 change in obliquity of the sun's rays1 to which must be added change in distance from the central luminary4 ,figure #bf shows that the sun reaches its greatest midday altitude on ,june #bast and its least on ,december #bast4 ,illustration3 ,,fig4 #bf4--,observer at center of picture at latitude #de4 ,showing altitude attained by the ,sun at midday and length of its track above the horizon at the ,summer and ,winter ,solstices and at the two ,equinoxes4 ,solar ,rays ,absorbed by the ,atmosphere4 ,the atmosphere of the earth absorbs about seventy-six per cent4 of the solar rays that pass through it4 ,about one half is absorbed by a cloudless atmosphere1 and nearly all is absorbed or reflected away by a cloudy air4 ,on the average about fifty-two per cent4 of the earth's surface is obscured by clouds all the time1 which reduces the total amount of heat that reaches the earth to but twenty-four per cent4 ,but in regions like the high plateau of the ,rocky ,mountains1 where there is little cloudiness or moisture in the air1 fully fifty per cent4 reach the earth4 ,at the equator1 when the sun is in the zenith at noon1 the rays strike the earth perpendicularly and reach the earth through the shortest air distance possible2 but for latitudes far north or south of the equator1 the rays are more oblique and must pass through an ever-increasing thickness of air as the latitude increases4 ,consequently the heat that reaches the earth at high latitudes decreases1 not only on account of the greater obliquity of the sun's rays1 but also because of the longer path of atmosphere traversed1 which causes a further loss by absorption4 ,the ,lag of ,earth ,temperatures4 ,the solar rays reach their greatest intensity on ,june #bast1 in the ,northern ,hemisphere1 when the sun attains the farthest point north1 and the obliquity of its rays is the least1 but the highest temperature of the air for the year does not occur on the average for a month or six weeks later1 due to the capacity of the earth and air to absorb heat2 and the maximum for the earth does not occur until still later4 ,the sun is the farthest south on ,december #bast1 but the minimum air temperature of the year1 on the average1 does not occur until a month later1 and at a later period in the earth4 ,at ,munich1 ,bavaria1 at a depth of four feet1 the minimum annual temperature occurs on the #b;d of ,march1 and the maximum on the #bdth of ,august4 ,for each increase of four feet in depth the time of occurrence of either maximum or minimum temperature is retarded twenty-one days1 the minimum not occurring until the #bc;d of ,may at a depth of #bj4b1 and the maximum being retarded until the #agth of ,november4 ,annual ,range in ,air ,temperature4 ,the difference in temperature between winter and summer increases from the equator northward and from all oceans toward the interior of continents1 and is greater in the middle latitudes on the eastern side of large bodies of land than on their western side4 ,yakutsk1 ,siberia1 has experienced #hj below zero in ,january and #ajb above in ,july1 making a range of #ahb4 ,dawson1 ,canada1 has a record of #fh below for winter and #id above for summer1 making a range of #afb4 ,in marked contrast with these large differences1 shown in the northern interior of continents1 is the annual range at ,samoa1 from a maximum of #ib to a minimum of #fb1 a range for the year of only #cj for this island of the ,pacific1 located near the equator4 ,reversal of the ,seasons in the ,two ,hemispheres4 ,the summer is shorter in the ,southern ,hemisphere than in the ,northern and the winter is longer1 but the ,southern ,hemisphere is nearer to the sun in the summer and farther away in winter1 conditions that tend to add to the extremes of both seasons4 ,because of the slowness of the earth in passing through one half of its orbit1 the northern summer lasts ninety-three days1 while that of the ,southern ,hemisphere lasts but eighty-nine days4 ,the result is that during like seasons and during the whole year the two hemispheres receive exactly the same quantity of heat4 ,only ,water ,vapor ,protects the ,earth from ,death by ,freezing4 ,in ,chapter ,,iv you are told that the earth is surrounded by four atmospheres that conduct themselves each quite independently of the others1 and that water vapor 7aqueous vapor7 is one of them4 ,water vapor plays the most important part in absorbing incoming rays and in absorbing and reflecting back outgoing heat rays from the earth4 ,without the vaporous atmosphere the sun's rays would be but slightly absorbed as they entered and radiation from the earth would readily escape through the atmosphere to outer space4 ,no matter how fiercely the sun might shine1 life on the earth would be entirely destroyed by cold4 ,when water vapor1 clouds1 or dust motes intercept certain portions of the sun's rays1 they change them from vibrations in ether to the motions of molecules1 and the motions of these molecules are expressed in a rise in temperature in the vapor1 cloud1 or dust4 ,earth radiations of heat1 having longer and slower wave lengths than those that come from the sun1 are more readily absorbed by the atmosphere4 ,one of the principal functions of the atmosphere is to protect the earth from the intense cold of outer space1 which must be near or at absolute zero--#dei below the zero mark4 ,why ,should ,not ,mountain ,peaks ,be ,warm8 ,they ,are ,nearer the ,sun4 ,the absorption by the atmosphere of both solar and terrestrial radiation is greater in the lower levels of the air1 where water vapor1 cloud1 and dust are the densest1 while the transmission of both incoming and outgoing radiation is more rapid through the pure air aloft4 ,thus we account for the coolness of all mountain peaks1 and the perpetual freezing temperatures of some1 even though they be located in the tropics1 and though their tops occupy positions several miles nearer the sun than the bases from which they rise4 ,how the ,earth ,cools at ,night4 ,radiation from the earth goes on day and night1 winter and summer4 ,during daylight the gain of heat is greater than the loss1 while at night the reverse is true4 ,after sunset both the earth and the air continue to cool by radiation unchecked by the incoming heat of the daytime4 ,the earth loses heat1 even under a clear sky1 more freely than the air1 with the result that the surface of the ground and of vegetation may fall to a temperature ten to fifteen degrees lower than that of the air at a few hundred feet elevation4 ,this condition is called 8temperature inversion40 ,the greater difference will occur when there is little wind to mix the air4 ,on a clear night the radiation outward will be rapid2 then1 if the wind be light1 there may occur an increase in temperature up to a height of two hundred to four hundred feet1 and then a fall1 reaching the surface temperature at about two thousand feet elevation1 unless the ground be wet1 or the location be adjacent to a considerable body of water4 ,a ,cloud ,covering ,cools by ,day and ,warms by ,night4 ,one of the principal functions of clouds is to conserve the heat of the sun4 ,a covering of cloud1 fog1 or dense haze may not only screen off the heat of day1 but greatly retard the lowering of temperature at night by reflecting and radiating back to the ground much of the heat that it has lost4 ,the ,temperature of ,oceans1 ,lakes1 and ,rivers4 ,the same quantity of heat falling upon different kinds of matter produces different temperatures1 depending on the capacity 7specific heat7 of each kind of matter to absorb or hold heat2 this is notably apparent when the matter is land1 water1 or air2 for the same quantity of heat will raise the temperature of a water surface only about one fourth as much as it will a land surface4 ,water rejects by reflection a considerable amount of the solar rays that fall upon it1 while land reflects but a small part2 and of that which is received upon the top layer of water much is rendered latent in the process of evaporation and does not impart warmth to the water4 ,solar rays also penetrate water to a considerable depth and are quite uniformly absorbed by the whole stratum penetrated4 ,these conditions cause large water surfaces and the air immediately over them to have a much lower temperature during the day and a much higher temperature during the night2 and also lower temperatures during summer and higher temperatures during winter1 than occur over a land surface of the same latitude4 ,fresh ,water and ,salt ,water ,have ,different ,freezing ,temperatures4 ,in the ratio of #ic4e to #ajj the specific heat of sea water is less than that of fresh water4 ,sea water is a better conductor of heat1 so that it penetrates to a greater depth in salt water in the same period of time than it does in fresh water4 ,sea water regularly contracts with falling temperature until its greatest density occurs at four degrees below freezing1 when it becomes solid ice and expands in the process of freezing2 otherwise it would not float4 ,a ,wonderful ,phenomenon4 ,in this respect a most wonderful and unexplainable phenomenon occurs with regard to fresh water4 ,not only sea water but practically all other forms of matter--liquid1 solid1 and gaseous--expand with increasing heat and contract with decreasing heat1 except fresh water between #ci and #cb1 which actually expands with falling temperature4 ,it seems as though the ,creator had gone over ,his work and made revisions and corrections here and there1 for unless the law with regard to the contraction of liquids with falling temperatures had been reversed for fresh water between #ci and #cb our rivulets1 streams1 lakes1 and rivers would freeze from the bottom upward and the life of inland water be wholly or partly destroyed4 ,even more calamitous would be the floods of springtime1 for melting snows and falling rains would spread over and erode the cultivated fields of the husbandman instead of being carried away by the open channels of streams1 as is largely done now4 ,the ,freezing of ,fresh and of ,salt ,bodies of ,water4 ,the freezing of water does not take place upon the surface of water only1 as many suppose4 ,congelation takes place about millions of minute atoms of matter carried by the water in suspension4 ,water expands in the process of freezing and each particle of ice1 no matter in what part of the body of water it is formed1 immediately rises to the surface because of the gain in its buoyance as it changes from the liquid to the solid form4 ,when the surface of water cools by radiation to a cooler air it gains in specific gravity and sinks and warmer water comes up to take its place and in turn be cooled and sink2 thus a circulation is established which continues in fresh water until every part of the body of water has fallen to #ci and in salt water to #bh4 ,at these temperatures the two waters reach their maximum density4 ,with the further cooling of salt water particles of ice form and rise to the top1 as already described4 ,with the cooling of fresh water below #ci the law that holds good for all higher temperatures is reversed and expansion of volume begins1 which continues until #cb is reached4 ,therefore1 fresh water of any temperature between #ci and #cb may float upon water that is considerably warmer2 in fact1 it has less specific gravity at #cb than at #df4 ,at #cb that which was a liquid becomes a solid and still further suddenly expands its volume4 ,the ,cold of ,ocean ,bottoms4 ,few have any idea of the enormous volume of cold water that lies upon the surface of the earth1 three fourths of which is covered with oceans whose depths average two miles and in many places are five miles4 ,below one mile in depth these oceans are always at about the freezing point of salt water1 which is #bh1 except in the tropics1 where it is but little warmer1 varying between #cd and #cf4 ,how ,temperatures of ,inclosed ,seas ,differ from ,those of ,oceans4 ,we will take the ,red ,sea as an example4 ,it is #ahj miles wide and extends in a nearly north and south direction for #adej miles1 about one half of it lying within the tropics4 ,evaporation takes place at a rapid rate1 but only the surface water of the ,indian ,ocean on the south is able to enter to take the place of that which is lost1 for a bar or sill at the entrance1 extending from the bottom to within twelve hundred feet of the surface1 separates the deep water of the sea from that of the outside ocean4 ,its surface temperatures vary about as the ,indian ,ocean1 being #he in summer and #gj in winter4 ,both bodies of water decrease in temperature at about the same rate down to the level of the sill1 where the temperature remains constant the year through at #gj4 ,here a marked difference occurs1 for the sea1 which has a depth of #gbjj feet1 maintains the same temperature of #gj all the way down to the bottom2 while the ocean continues to decrease in temperature down to a depth of about six thousand feet1 where a temperature of #cd to #cf prevails throughout the year4 ,a similar condition exists with relation to the ,mediterranean and the ,atlantic ,ocean4 ,at the top of the sill1 which is #aadj feet below the surface1 the temperature of both bodies is #ee1 and this degree of heat is maintained all the way down to the bottom of the ,mediterranean1 while in the ,atlantic ,ocean1 at the same depth as the bottom of the ,mediterranean1 the temperature is only #ce4 ,how the ,temperature of ,water ,changes with ,latitude1 ,season1 and ,depth4 ,it is impossible to name a given temperature as prevailing over bodies of water at all places on the same parallel of latitude1 because ocean currents soon move water heated in one latitude to a higher or a lower position4 ,at the equator the surface temperature is between #hb and #hd2 it changes less than one degree between day and night1 and not over five degrees between winter and summer2 and below twenty-four hundred feet there is no difference between the seasons1 the daily variation ceasing at less than a hundred feet4 ,below six thousand feet the temperature is always near the freezing point of fresh water4 ,in the middle latitudes the surface variation is from #ej in winter to #fh in summer4 ,at latitude #gj ,n4 the surface temperature has but a small daily variation1 and a yearly range of from #ce for winter to #de for summer2 at a depth of twenty-four hundred feet it remains steady at #cb4 ,from this level there is a gradual decrease to a depth of six thousand feet1 where a constant temperature of #bh exists1 and below this there is no change4 ,the temperature of ,lake ,superior decreases down to a depth of two hundred forty feet1 where a temperature of #ci continues throughout the year1 as it does downward for the remainder of the distance to the bottom1 which has an average depth of nine hundred feet4 ,direction of ,wind ,affects ,shore ,temperature of ,water4 ,onshore winds skim off the warm surface water and drive it shoreward1 where it banks up1 and1 pressing downward1 causes the colder water beneath to flow back seaward4 ,in like manner1 offshore winds blow off the top water near the shore and send it out to sea1 and colder water rises to take its place4 ,great ,heat of the ,earth's ,interior4 ,we are ignorant of the conditions of matter under the heating effect of the enormous pressure that exists near the center of the earth1 but it is probable that pressure prevents it from changing from a solid to a liquid or a gaseous form4 ,the surface of the solid earth rises to a much higher temperature as the solar rays fall upon it than does a water surface1 or the air immediately above1 because it is a poor reflector1 a poor conductor1 and a poor radiator1 and when dry does not get any cooling effect from evaporation4 ,solar heat ceases to be apparent at a depth that varies with the latitude and the conditions of the soil with regard to moisture and specific heat1 but everywhere at less than fifty feet4 ,at the poles and for some distance away the earth is covered with ice or snow the entire year and is frozen to a considerable depth4 ,in the interior of ,siberia and some parts of ,alaska only a thin stratum of soil thaws out under the heat of summer4 ,beginning at about fifty feet1 there is an increase of temperature downward1 but it is not the same for all places1 varying from a degree for forty feet to a degree for one hundred feet4 ,taking the average of the increase with depth1 water would boil at ninety-five hundred feet and the hardest rock be molten at thirty miles4 ,at a depth of #cdij feet near ,berlin1 the temperature was found to be #aaf1 while it was only #ajh at the same depth at ,wheeling1 ,west ,virginia1 and in both places there is no change from day to night or from winter to summer4 ,soil ,usually ,warmer ,than ,air ,next ,above4 ,in summer1 ,june to ,august1 the bare1 dry1 top soil is warmer than the air ten feet above during all hours of the day and night1 at times the difference being as much as forty degrees at midday4 ,during winter1 ,december to ,february1 it is slightly cooler1 except between #i ,a4,m4 and #c ,p4,m4 when the excess is seldom more than ten degrees4 ,evaporation from a wet soil lowers its temperature below that of the air immediately above through the rendering latent of a large quantity of heat4 ,a melting snow surface also is below the temperature of the air because of the heat employed in changing the snow to the liquid form4 ,let ,mother ,earth ,cool and ,refresh ,you ,during the ,heat of ,summer4 ,how little the average man realizes the possibilities for improving his condition that lie close at hand4 ,he does not know1 or he is indifferent to the fact1 that only three feet from the surface of the ground it is as cool at midday as at midnight1 and that there is no diurnal variation in temperature below that depth1 and no annual variation below a depth of from thirty to forty feet4 ,if one were to set down the temperature of each day1 add the numbers at the end of the year1 and divide the sum by #cfe the quotient would equal the temperature always found at that place at a depth of about thirty feet4 ,the temperature of a deep-flowing spring is always about the mean annual air temperature of the place4 ,here is health-giving coolness for summer and warmth for winter of which one takes little heed and derives practically no profit4 ,remarkable1 is it not8 ,and these beneficent conditions are universal and available for all1 except to those crowded into congested centers of population4 ,the temperature is #ed in the ,mammoth ,cave in ,kentucky and shows no change from day to day and from winter to summer4 ,during the extreme heat of summer and the cold of winter many could profitably1 healthfully1 and pleasantly live below ground4 ,during such periods the cellar of the house1 which should be deep and spacious1 even extending beyond the dimensions of the edifice above1 if a continuous supply of pure air could be forced through it1 or natural ventilation accomplished by the plan outlined below1 should be the lounging1 resting1 and sleeping place of the occupants of the household4 ,it is not impossible or extremely difficult to change the stagnant1 moist1 germ-laden1 ill-smelling air of the average cellar1 in which it is positively dangerous to spend much time1 into active1 pure1 and delightfully healthful air1--air in which the worn and weary worker from the heat of the farmer's field1 or the artisan and the clerk from the debilitating temperatures of the factory and the office could recuperate from the toil of the day1 and from which they would go forth each morning invigorated for another day's efficient service1 instead of dragging weary limbs from hot1 sleepless beds1 each morning less in energy than the day before4 ,as is shown in other parts of this book1 the researches of ,huntington have proven conclusively that man is at his lowest physical and mental points of efficiency1 and more subject to the contraction of disease through weakness1 in midsummer and midwinter1 and that the hotter the summer and the colder the winter the less is his energy and the lower is his power of resistance4 ,the whole problem is one of ventilation4 ,while this is simple1 it must be scientifically done4 ,the ideal location for a living cellar is a hillside4 ,it is easy to install ventilators in the roof of a cellar no matter where located1 but these are of no avail whatever if there is not adequate air drainage at the bottom of the cellar4 ,from the cellar in a hillside a conduit can lead from the bottom of the inclosure and have its opening at a lower level1 thereby accomplishing drainage and circulation1 which are all-important in the creating of a sanitary condition of air under the cool earth4 ,for each thousand cubic feet of cellar space there should project from the roof1 to a height of at least six feet above ground1 a separate ventilator shaft of at least one square foot cross-section dimension4 ,a like ventilating capacity should be provided from the bottom outward to a lower level1 but here two or more shafts may be combined in one1 so the proper capacity is secured4 ,during the day the draft will be upward through this system4 ,but at night1 except when the wind is brisk1 the direction of movement of the air is reversed1 and the cool air of the minimum temperature of night or early morning1 because of its greater density1 drops down into the cellar4 ,the drainage shaft should be provided with a damper1 which should be closed in the early morning1 about daybreak1 entrapping the cold air of night4 ,the lower opening should be covered with wire netting1 to exclude small animals1 and the whole construction be of concrete1 rendering it imperishable and rat-proof4 ,inexpensive but ,efficient ,cold ,storage4 ,such a sanitary cellar as described above provides an excellent storage for fruits and vegetables1 comparing favorably with the much more expensive artificial refrigeration4 ,by an intelligent manipulation of the damper in the lower shaft1 cool storage may be provided for fruit and other produce in the early fall1 and protection secured against the extreme cold of winter4 ,why ,does ,air ,cool with ,ascent and ,heat with ,descent8 ,if a mass of air be elevated #ahc feet it will be found to have lost one degree in temperature1 because there is less air above to exert pressure upon it and it therefore expands to greater volume1 and in the process of expansion work is performed which employs heat and renders it latent4 ,one minute1 one hour1 or a thousand years thereafter1 if this same air be lowered to its former elevation1 it will be compressed into its previous dimensions and the heat energy that formerly was employed to expand it will be restored to the sensible condition4 ,this ratio of #ahc feet to one degree does not hold for any extended movement1 because1 as soon as the dew point of the air is reached1 condensation in the form of cloud or rain occurs and the heat of condensation is released2 that is to say1 the same quantity of heat employed to create the water vapor at some previous time and thereby rendered latent is now become sensible and partly makes up for the loss by expansion as the air ascends4 ,the average is therefore about three hundred feet for one degree4 ,height of ,freezing ,cold in the ,free ,air4 ,the frost level remains constant1 winter and summer1 over the equator at about eighteen thousand feet4 ,elsewhere this level rises and falls with the seasons1 the amplitude of the movement increasing with latitude and being greater over land than over water on the same parallel4 ,daily ,range of ,temperature in the ,free ,air4 ,the difference between the temperature of day and that of night decreases with altitude in the free air and ceases at about eight thousand feet4 ,it is greatest during clear weather and least in cloudy weather4 ,narrow valleys may show a greater daily range than hilltops4 ,when the sky is clear1 radiation from the hillsides may heat the air in a valley to almost furnace heat at midday1 while at night the air1 coming in contact with cool vegetation higher up1 chills and1 gaining in weight by contraction1 flows down and collects in the valley1 making the bottom of the valley warmer during day and colder during night than the air above4 ,often moisture-laden winds precipitate much of their water vapor as the air cools by expansion in passing over a mountain range4 ,these winds carry a comparatively dry air over to the leeward side of the mountain1 where the daily range of temperature will be much greater than on the windward side at the same elevation4 ,san ,francisco1 where the prevailing winds come from the ocean1 has a less range than ,new ,york1 where the predominating winds are from the land2 but ,new ,york is influenced by its proximity to the ocean1 for its range is much less than at ,denver1 in the interior of the continent4 ,the range is less on the east side of ,lake ,michigan than on the west side1 as it is with relation to all similar bodies of water4 ,man ,soon ,adjusts ,himself to ,changes in ,altitude4 ,in ,colonial days it was noted that horses coming down from the mountains in ,north ,carolina ran swifter in the races the first day or two after changing to a lower level4 ,in going to a higher altitude an increase in the number of red corpuscles in the blood enables it to absorb oxygen more readily1 and thus compensate for the loss in the density of the air4 ,because of this gain in the chemical activities of the life current1 one feels a marked increase in strength on coming to a lower level1 but the gain lasts for only a short time before there is a readjustment to former conditions4 ,persons with weak hearts may not be able to live at an altitude of four thousand feet1 and most people experience inconvenience1 at least1 on first reaching ten thousand feet2 but nature is accommodating1 and a number of large cities prosper at altitudes of from one to two miles4 ,,chapter ,,xi ,,how ,,climate ,,is ,,modified ,,and ,,controlled ,if the surface of the earth were all land1 and the axis of the earth's rotation were perpendicular to the plane of the earth's orbit1 the day and the night would be equal everywhere1 and there would be no seasons4 ,there would be no wind1 for the friction of the air against the rotating earth would soon cause all levels of the atmosphere to take up the exact easterly velocity of the solid body below4 ,the atmosphere would be contracted by cold and drawn downward so as to have less depth at the poles than at any place having latitude1 and it would be deepest at the equator1 where the direct rays of the sun would expand it to an altitude of probably twice what it could have at the poles4 ,centrifugal force--the force that causes mud to fly off the rim of a swiftly rotating wagon wheel--would further lower the height of the atmosphere at the poles and cause it still more to extend outward at the equator4 ,the atmosphere would soon adjust itself to these constant conditions and forces and thereafter remain at rest relative to the earth4 ,there would be no life1 for there would be no vaporous atmosphere if the surface all were without water4 ,there would be extremely little heat to disturb the atmosphere with motion1 for the dry gases of the atmosphere are practically diathermanous1 and the heat of the sun would pass out by radiation from the burnt and parched surface of the earth during daytime without imparting more than a minute fraction of its energy to the atmosphere2 and at night the thin surface of the top soil that had been heated to a furnace temperature during sunshine would be quickly locked in the fastnesses of intense cold--probably #bjj below zero4 ,if we now incline the axis of our imaginary earth #bc1 we shall introduce seasons whose only change1 the one from the other1 will be in the duration of sunlight1 as there is no water vapor to absorb and utilize the sun's rays in the initiation of motion and the creation of storms4 ,we are assuming that there would be enough heat absorbed to prevent the atmosphere from liquefying1 which it would do at any temperature lower than #cab below zero4 ,if the temperature were to fall below the liquefying point of air1 we would have the singular phenomenon of the air expanding to a gas during daylight and condensing to a liquid during nighttime1 and1 of course1 that would mean motion and winds1 but of such a nature that one would hardly dare speculate as to their peculiarities4 ,we introduce these hypothetical cases for the purpose of conveying a clearer idea of the overlapping of conditions and the combinations of forces that influence and control the seasons1 the climate1 and the weather of the earth4 ,if the surface of the earth were all water and its axis perpendicular to the plane of its orbit1 the day and the night would everywhere be equal and there would be no seasons4 ,with a water surface there would be an atmosphere nearly if not quite saturated with vapor of water1 in other words1 of practically one hundred per cent4 relative humidity4 ,it is doubtful if either animal or vegetable life could exist2 the first would die of internal heat1 because a saturated air would permit of no cooling by evaporation from the pores of the skin1 or from the tongue and mouth of animals that do not perspire2 and the second could not grow without the chemical action of sunshine1 which is a necessary part of the laboratory of the leaf of every growing plant1 the sunshine acting upon the green granular matter which constitutes the chlorophyll of the plant4 ,there would be little difference between the temperature of day and of night--probably not more than one degree4 ,as the earth would everywhere and at all times be covered with a deep stratum of cloud there would be little loss of heat to space by radiation and the temperature would be excessive1 rising in the tropics to near the boiling point4 ,we will assume that the atmosphere would reach a stable and unchanged condition of great heat and humidity and be without motion or precipitation4 ,if now we incline the axis of this water-covered earth and introduce the complication of seasons1 we shall not only have variation in the hours of sunshine1 increasing as we go from the equator toward the poles1 but1 the capacity of air for moisture being less and less with falling temperature1 we shall have downpours of rain as the summer slowly merges into fall and the latter into winter4 ,although the air will be saturated1 there probably will be no rainfall from the time when the temperature begins to rise after midwinter until it reaches and passes the maximum heat of summer4 ,it is fair to assume that during the rainy period there will be cyclonic storms with torrential precipitation1 and that the anti-cyclones that are a necessary concomitant of cyclones1 while they may cause a temporary cessation of precipitation in the area that they cover1 by the dynamic heating of the air in their downward motions1 will be ineffective in fully clearing away the clouds from a water-covered earth4 ,it is doubtful if such an earth would be suitable for life1--certainly not for man4 ,the ,real ,earth of ,land1 ,water1 and ,inclined ,axis4 ,the different manner in which land and water surfaces absorb1 radiate1 and reflect the heat from the sun has a profound influence on climate1 which also is modified by latitude1 elevation above sea level1 elevation above a valley or above a surrounding plane1 direction of wind1 height and trend of direction of hills and mountains1 the position of lakes and inland seas1 the relative position and magnitude of continents and oceans1 storm tracks1 and ocean currents4 ,influence of ,continents and ,oceans on ,climate4 ,charts #a and #b 7pages #ii and #ajj71 constructed from observations taken on ships and on land1 for a long series of years1 show certain ,highs and ,lows of vast extent1 sometimes called 8,centers of ,action01 because they do not travel across continents and oceans1 as do the migrating ,highs and ,lows that cause weather4 ,rather do they slowly reverse their relative positions between winter and summer4 ,continents cool by radiation in winter more rapidly than do oceans2 the air contracts1 settles down and grows denser and air flows in at the top from the oceans and outward at the surface of the earth toward the oceans2 thus is built up the winter ,highs1 or centers of action1 on continents4 ,continents heat up by absorption in summer more rapidly than do oceans2 the air expands1 rises1 and flows away in the upper levels to oceans and flows in at the bottom from the oceans2 and thus are the ,lows1 or centers of action1 established on continents in summer4 ,it is apparent that these processes must be reversed for the oceans1 and that the ,highs will be found there in the summer and the ,lows in the winter4 ,carefully follow the illustrations of these principles by examining the whole region north of the equator on ,charts #a and #b4 ,in the ,southern ,hemisphere there is not such a pronounced shifting of the ,highs and the ,lows from oceans to continents and back again1 with change in the seasons1 as there is in the ,northern ,hemisphere1 because of the small area of land in comparison with that of water2 but in the midst of the southern summer1 which occurs in ,january 7,chart #b71 ,lows are shown over ,south ,america1 ,africa1 and ,australia4 ,note how the winds blow out of all the ,highs and into all the ,lows4 ,also observe that the winds generally blow from about latitude #cj north and south towards the equator1 due to the great heat of the tropics1 which causes the air to rise and in the high levels to flow northward and southward1 settling down to the earth again through the belts of high pressure that irregularly encircle the earth at latitudes #cj north and south4 ,in the interior of continents the temperature falls lower at night and rises higher during the day1 and falls lower in winter and rises higher in summer than on any of their coasts4 ,on the coast of central ,california1 for instance1 the ocean is so cool in summer and the winds blow so steadily from it that the thermometer ranges between #ee and #gj1 even when there are temperatures of over #ajj but a few hundred miles away in the great interior valleys1 or on the broad plateaus of the mountains4 ,new ,york and ,boston1 in nearly the same latitude1 also have their summer temperatures modified by ocean influence1 but they are on the east side of a broad continent1 where the prevailing westerly winds give to them more the character of a continental climate than one marine2 but occasionally the east wind1 for a short time1 gives to them the modifying influence of the ocean4 ,in the winter the influence of the oceans is to modify the extremes of cold1 the same as they do the excessive heat of summer4 ,illustration3 ,,chart #ab4--;,,average ,,maximum ,,temperature ,,for ,,july 7,henry74 ,chart #h 7page #abi7 showing the lowest temperatures ever recorded at ,weather ,bureau stations1 and ,chart #ab1 presenting the average of the highest daily temperatures of ,july1 graphically show1 clearer than any text can describe1 the influence of continents and oceans on climate4 ,on the ,atlantic the average maximum of day varies from #gj on the ,maine coast to #he on the coast of ,north ,carolina2 while on the ,pacific1 where the marine influence is stronger1 the average is from #fe on the ,washington coast to #hj on the coast of southern ,california4 ,but near the center of the ,united ,states where the continental influence predominates1 the average of the highest daily temperatures varies from #he to #ij4 ,on ,chart #h1 showing the lowest temperatures1 the line of #bj below zero passes through ,boston1 southwest to ,chattanooga1 west to ,flagstaff1 ,arizona1 and then irregularly north to ,seattle1 showing the influence of both oceans in carrying the line northward4 ,illustration3 ,,chart #ac4--,,ocean ,,currents4 ,because of the vast extent of the ,eurasian 7,europe and ,asia7 continent the difference between continental and marine climates is more marked than in the ,western ,hemisphere4 ,huntington and ,cushing1 in their splendid work on 8,principles of ,human ,geography01#c make a comparison between the southern ,lofoten ,islands1 off the coast of ,norway1 and ,verkhoyansk in ,siberia1 which probably furnish the greatest contrast to be found anywhere between places of the same latitude4 ,although both are inside the ,arctic ,circle1 the influence of the ,atlantic ,ocean with its warm-water currents coming all the way from the tropics 7,chart #ac7 protects the ,lofoten ,islands from the extreme cold that otherwise would come to them2 vegetation remains green and cattle are pastured every month in the year4 ,but the ocean retains nearly the same temperature in summer as in winter1 and as a result the ,islands are too cold to grow trees or many crops4 ,verkhoyansk is so different that one can scarcely believe that both places are in the same latitude4 ,at the ,siberian town the winter temperature falls to #gj or #hj below zero every winter1 and has been known to register #ij below zero4 ,it is said that steel skates often will not 8take hold0 but slip sideways as well as forward on the surface of the excessively cold ice4 ,this doubtless is due to the fact that under ordinary winter cold the weight of the skater melts a thin film of water under the edge of the skate1 which freezes instantly when the skate passes and relieves the pressure4 ,but here the cold is so intense that the weight of no skater is sufficient to lubricate his movements with water molecules4 ,remarkable to relate1 the summer at ,verkhoyansk is warmer than in the islands off the ,norwegian coast1 due to the rapidity with which the land surface warms up under the action of the solar rays in the midst of a continental area remote from water1 #ge to #hj frequently being recorded during the long summer days4 ,the ground never thaws for more than a foot or so1 but a number of crops are successfully grown4 ,in the interior of a continent like that of ,siberia or of ,north ,america not only the changes from season to season but from day to night are extreme2 while in mid-ocean the diurnal and the annual range of temperature is small1 day and night1 winter and summer being much the same4 ,a place is influenced by the ocean in proportion to its distance from the sea1 the presence or the absence of hills or mountains between the place and the water1 and by the fact that the prevailing winds come from or go to the ocean4 ,cities as far inland as ,baltimore and ,philadelphia have their extremes of temperature somewhat modified by the ,atlantic ,ocean1 and if it were not for the ,coastal and the ,sierra ,nevada ,mountains the influence of the ,pacific ,ocean would be felt at least as far inland as ,denver1 and the great ,rocky ,mountain plateau would be one of the garden plots of the world4 ,the influence of the ,pacific would reach inland farther than now does the ,atlantic because of the prevailing westward drift of the atmosphere in all middle latitudes4 ,exaggeration of the ,forest ,influence on ,climate4 ,chapter ,,xiii1 on ,change of ,climate1 shows more in detail the process whereby the sun lifts up the water vapor from the ,gulf of ,mexico and the ,atlantic ,ocean and how cyclonic storms draw this vaporous atmosphere northwestward far into the interior of the continent1 the ,alleghany ,mountains not being high enough to offer serious obstruction4 ,the writer would again caution the reader not to be misled by any pseudoscientist1 no matter how worthy his purpose may be1 who would teach that the operations of men in changing forest areas to cultivated fields1 gardens1 villages1 and cities1 has in the slightest degree harmfully affected the climate1 or augmented floods or intensified droughts4 ,a field of grass1 of wheat1 of corn2 an orchard of fruit2 a highway bordered with towering1 majestic oaks and elms2 or a grove of cultivated trees about a prosperous home is just as beneficial to the climate as the thickest and most impenetrable forest and far more pleasing to the eye and helpful to mankind4 ,forests should be protected1 conserved1 and grown because we need timber1 not because a lot of foolish people are writing nonsense about them4 ,influence of ,lakes and ,rivers4 ,with the exception of contributing to the formation of occasional fogs over their surfaces and the adjacent low lands1 through the rising of warm water vapor into the cold air that often collects at the bottom of valleys during nighttime1 rivers exercise little influence on climate4 ,lakes exert a modifying influence on the temperature of places near their shores but only for a few miles therefrom1 and they are too small to exert any appreciable influence on rainfall4 ,if one examine charts showing the average rainfall for the ,united ,states by seasons1 he will observe that the amount gradually shades off as the distance from the ,gulf or ,ocean increases1 without any relation whatever to the five ,great ,lakes4 ,deserts exist on either side of the ,caspian ,sea1 although it slightly increases the rain of the ,elburz ,mountains to the south4 ,if these great bodies of water do not influence the rainfall1 how ridiculous to assume that the changing of forest areas to other forms of vegetation possibly can affect precipitation or influence droughts4 ,stress is laid on the fact that some land is left bare and then is eroded into deep gullies4 ,this is true1 but the fault is one that may be corrected by a proper system of plowing and cultivation4 ,and at most the area so eroded is so infinitesimal in comparison to the vast regions changed from forests to growing crops as to be negligible4 ,illustration3 ,,chart #ad4--,,mean ,,annual ,,isotherms 7,buchan74 ,influence of ,ocean ,currents on ,climate4 ,climates are markedly influenced by the currents of oceans4 ,charts #ae and #af show the normal wind circulations of the globe2 note that the centers of the great swirls are coincident with the location of the ,high and the ,low centers of action located on ,charts #a and #b4 ,next observe ,chart #ac1 showing the ocean currents1 and it will be seen at once how closely the circulation of the great ocean currents follows that of the winds1 due to the friction of the air upon the water1 and to the interposition of bodies of land that turn about or deflect the currents4 ,illustration3 ,,chart #ae4--,,normal ,,wind ,,direction ,,and ,,velocity ,,for ,,january ,,and ,,february 7,kppen74 ,illustration3 ,,chart #af4--,,normal ,,wind ,,direction ,,and ,,velocity ,,for ,,july ,,and ,,august 7,kppen74 ,water has a greater capacity for heat than nearly any other substance4 ,it requires ten times the quantity of heat to raise a pound of water one degree that it does a pound of iron4 ,the oceans therefore store up vast quantities of the heat of the sun and1 unlike the continents1 distribute this heat northward and southward without regard to latitude4 ,much of the heat of the tropics is thus transported far northward and southward from the equator4 ,the extensive eddy-like circulation of the south half of the ,north ,atlantic ,ocean sends currents northward along the coast of the ,united ,states which set eastward at latitude #dj4 ,a part of these reach the coast of ,spain and then turn south2 the greater part spread out in mid-ocean and move northeast1 bathing the coasts of the ,british ,islands1 ,iceland1 and ,norway4 ,they still retain some of the heat that they absorbed from a tropical sun1 and they therefore give to the coasts that they reach a higher temperature than they would have if the ocean waters were moving from the north1 or than they would have if there were no currents at all4 ,on ,chart #ad note how the isothermal lines are carried northward by these currents as they cross the ,atlantic ,ocean4 ,the ,gulf ,stream mingles with these northeast currents but adds little to their temperatures1 for the general ocean circulation would produce practically the same effects if there were no ,gulf ,stream4 ,follow the currents down the coast of ,spain and of northeast ,africa2 then note on ,chart #ad the southward trend of the lines of equal temperature1 as the currents bring colder water southward to cool the air4 ,next examine the currents of the ,pacific and the isothermals4 ,the currents moving northward towards the equator along the west coast of ,south ,america1 and those moving southward1 also toward the equator1 along the west coast of the ,united ,states and ,mexico cause a bulging of the isothermal lines from the positions that they would occupy if there were no currents coming from colder regions4 ,influence of the ,gulf ,stream on ,climate4 ,from either side of the equator the surface winds 7,charts #ae and #af7 blow the water westward1 causing what are known as the 8,equatorial ,currents0 7,chart #ac74 ,the eastward projection of the coast of ,south ,america divides the ,atlantic equatorial current into two parts2 one goes south along the coast of ,south ,america and sets up the circulation in the ,south ,atlantic1 which sweeps north along the southwest coast of ,africa4 ,the other passes to the northwest1 a part setting up the ,north ,atlantic circulation and the remainder sweeping through the ,windward ,islands and storing itself in the ,gulf of ,mexico1 whence it is driven out at a velocity of some five miles per hour through the narrow channel between ,key ,west and ,cuba4 ,here it has a depth of half a mile and a width of forty miles4 ,its velocity is accelerated because it enters the ,gulf in a broad sweep and passes out through a constricted channel4 ,it retains its individuality as a warm river passing through the ocean because of its greater velocity and higher temperature than the waters in which it finds itself soon after it leaves the ,gulf2 but it gradually merges with the great ,atlantic circulation as it passes to the middle of the ocean4 ,it is the opinion of the writer that its influence on climate has been exaggerated1 that the warming of ,europe that is credited to the ,gulf ,stream is accomplished by the mere presence of the ocean to the westward and to the general circulation of that ocean without regard to the wonderful phenomenon known as the ,gulf ,stream4 ,effect of ,valleys on ,day and ,night ,temperatures4 ,valleys affect temperatures in proportion to their depth and width4 ,a deep1 narrow valley might have the effect illustrated by ,figure #bg1 if the time were summer and the sky clear4 ,during the daytime radiation would warm the interior so that the bottom of the valley would have a much higher temperature than the free air at the top of the valley1 and the movement of the air would be sluggishly down the center and up the sides of the depression4 ,during nighttime all the conditions would be reversed4 ,vegetation1 losing heat by radiation much faster than the air1 would cool the latter as it came in contact with the sides of the valley4 ,the air would slowly descend along the sides through gain in specific gravity and collect at the bottom with a temperature much lower than it had when it started its descent4 ,illustration3 ,,figure #bg4 ,summer day temperature in a narrow valley4 ,summer night temperature in the same valley4 ,effect of ,mountains on ,climate4 ,the rarity of the atmosphere of mountains readily allows the rays of the sun to pass through it and thus the surface of mountains is quickly warmed1 but the same conditions permit a rapid radiation at night1 so that there are considerable extremes of temperature4 ,air cooled by contact with a mountain may flow down its sides at night and collect in depressions below1 often causing frost on still nights where the temperature higher up is much above freezing4 ,mountains may be more cloudy and rainy than plains1 for the currents of air that cross them must rise1 and in rising they cool by expansion and often reach the dew point of the air1 moisture being precipitated in the form of clouds1 rain1 or snow4 ,often a peak is constantly capped with a crown of clouds4 ,mountains may intercept vapor-bearing winds from oceans1 force them to such an elevation that their vapor is largely precipitated on the windward side of the mountain1 and receive them on the leeward side as dry1 rainless winds4 ,vast desert areas are often the result4 ,a good example is presented in the case of the ,pacific coast mountains and the desert plateau to the east4 ,mountain peaks may be covered with snow1 even though they be located in the tropics1 if their elevation be sufficient4 ,this is because the absorption of both incoming and outgoing radiation is so much greater in the lower reaches of the atmosphere1 where the water vapor is densest4 ,wherever observations have been made they have shown that the temperature of the air on high mountain peaks and crests and for a distance of one to three hundred feet above them is cooler than adjacent free air of the same height1 due to upward deflection of air currents and their cooling by expansion1 and to radiation from the peak4 ,the ,himalayan ,mountains exercise a profound effect on the climate of ,asia4 ,the monsoon 7any wind that alternates annually in direction or force7 of summer brings the moist air from the ,bay of ,bengal and precipitates torrential rains from it as it ascends to higher and higher elevations in passing over the great heights of the mountains4 ,at a place four thousand feet above the sea and not distant from ,calcutta1 the annual rainfall is #dff inches1 while the average for most of the region east of the ,mississippi ,river is only forty inches4 ,more than forty inches have been known to fall in one day in the ,himalayan ,mountains4 ,as in the case of all very high mountains1 the rainfall increases in these mountains up to a certain elevation and then decreases4 ,north of the mountains the monsoon passes into the interior of ,asia with withering dryness and vast deserts are the result4 ,illustration3 ,,fig4 #bh4--;,average ,monthly ,temperature and ,rainfall of ,typical ,places in ,north ,america4 7,huntington and ,cushing47 ,figure #bh graphically presents the average monthly temperature and rainfall of typical places in ,north ,america1 and ,figure #bi of places in the ,old ,world4 ,here may be seen every phase of climate from tropical to temperate and to cold1 and from marine to continental4 ,by studying the winds on ,charts #ae and #af and the ocean currents on ,chart #ac1 the reader should be able to find an explanation for the different conditions shown4 ,for example3 ,mazatlan and ,vera ,cruz are both on the coast of ,mexico1 the first on the west and the latter on the east4 ,each has a rainy period in the summer1 but at ,vera ,cruz the rain begins earlier and lasts later and is much heavier4 ,the reason is that they both have north winds in winter 7,charts #ae and #af71 but in summer ,vera ,cruz receives winds direct from the ,gulf of ,mexico and at ,mazatlan the winds continue to blow from the north1 with but a slight inclination landward4 ,again1 the explanation for the fact that ,mazatlan has a monthly range of temperature from #fj in winter to #hj in summer1 while ,vera ,cruz has a range of only #gj to #hj is found in the wind direction4 ,illustration3 ,,fig4 #bi4--;,average ,monthly ,temperatures and ,rainfall of ,typical ,places in the ,old ,world4 7,from 8,principles of ,human ,geography40 ,john ,wiley ,sons47 ,the ,city of ,mexico is wonderfully favored by climate4 ,here a moderate rainfall occurs from ,may to ,september4 ,the oceans are not far distant on either side1 as distances are measured continentally1 but its great elevation on a table-land relieves it of the torrential rains usual to the tropics2 and yet it is close enough to marine influence so that its air has not the nerve-irritating dryness of the plateau of the ,rocky ,mountains1 and it has a remarkable evenness of temperature between winter and summer1 with a monthly range between #ej and #fj4 ,its range between day and night is sufficient to be stimulating4 ,still looking at ,figure #bh1 note the remarkable similarity between the climate of ,pittsburgh and ,toronto4 ,each has about the same rainfall and it is almost equally distributed throughout the months of the year4 ,the only difference is that ,toronto is a little colder4 ,st4 ,paul and ,kansas ,city1 typical of the climate in the interior cities1 have a small amount of precipitation in winter1 considerable in summer1 and a wide range of temperature2 while the ,pacific coast cities have dry summers1 and winters that vary from three inches of rain at ,los ,angeles to fourteen inches at ,astoria1 with no excesses in temperature4 ,temperatures ,aloft in the ,atmosphere4 ,kite and balloon observations have not been continued long enough1 nor have they been made at a sufficient number of places1 to give one the data from which the climate of any considerable altitude in the free air may be determined1 but from a large number of free balloon observations made with self-recording instruments1 in the middle latitudes of this and foreign countries1 ,figure #a 7page #ab7 has been constructed1 which shows the manner in which the temperature decreases with elevation up to eighteen kilometers 7eleven miles74 ,note how rapidly it falls with elevation up to eleven and a half kilometers 7about seven miles74 ,this depth of air measures the thickness of the turbulent stratum in which cyclones and anti-cyclones operate4 ,at its top the temperature always is about #fd below zero in winter and #gj below in summer4 ,and right here occurs a most wonderful phenomenon1--one of which scientists were entirely ignorant less than two decades ago4 ,at first it was thought that there was something wrong with the recording thermometers1 for they failed to register falling temperature with gaining altitude after the storm stratum was passed at seven miles4 ,then it was noted that all instruments displayed the same peculiarity1 and the 8,isothermal ,stratum0 7equally heated region7 was discovered1 in which the temperature maintains the same degree of intense cold so far as exploration had been made4 ,from ,mount ,weather1 under the direction of the writer1 a balloon was flown to nineteen and one tenth miles before it exploded and sent a parachute gently down to earth with its precious record4 ,this flight showed practically no change in temperature after the isothermal stratum was reached4 7,see ,chapter ,,iii47 ,one is reasonably safe in assuming that there is no oxygen beyond an altitude of thirty miles and that at fifty miles the nitrogen becomes inappreciable1 and that1 therefore1 the temperature must shade away to practically nothing when the void of outer space is reached1 notwithstanding the presence of the newly-discovered isothermal stratum nearer the earth4 ,,chapter ,,xii ,,civilization ,,follows ,,the ,,storm ,,tracks ,,the ,,most ,,dominant ,,races--,,those ,,that ,,best ,,co-,,ordinate ,,the ,,mental ,,and ,,physical ,,faculties--,,are ,,found ,,to ,,exist ,,under ,,certain ,,climatic ,,conditions--,,change ,,the ,,climate ,,and ,,you ,,change ,,the ,,man ,in a climate where man needs little protection from the elements1 where he may lie upon his back in the shade and with his bare toes pick wild growing fruit to nourish his body1 one will find no great leaders in art1 literature1 science1 statecraft1 or industry2 likewise1 in the ,arctic1 where man simply gathers enough blubber to supply his animal wants and then burrows beneath the snows of fierce winters1 one will not find leadership or creative genius4 ,the regions of greatest human potential are limited to such portions of the temperate zone as have an abundance of rainfall1 frequent changes in the weather1 and an alluvial soil4 ,in other words1 the most perfect composite of human resourcefulness is found where nature is neither so fierce as to crush human aspiration1 nor yet so gentle as to lull human desire4 ,humboldt says3 8,man is the product of soil and climate2 he is brother to the tree1 the rocks1 and the animals40 ,we shall endeavor to show that civilization and the greatest human potential follow the storm tracks of the world1 and that climate is the most important factor in his environment1 for without its proper adjustment to his needs the richest soil and the most beneficent form of government fail to bring out the best that is in him4 ,empire is determined as much by direction and force of the wind and changes in the weather as by the scheming of politicians1 the deep-laid plans of diplomats1 or the marshaling of battalions4 ,the first thing that vigorous man requires is active atmospheric conditions and in his migrations he follows the climatic lines that appease his desires4 ,a climate of little change between day and night and between winter and summer is soothing and at the same time deadening to the human faculties2 but changes should be frequent rather than violent4 ,the daring1 the creative1 the pioneering1 the persistent spirits of mankind1 like snow birds showering themselves with icy crystals1 revel in the cool air1 the perpetual oscillations of temperature1 and the frequent changes from sunshine to cloud that pertain to the regions where storms are most numerous4 ,some days the mind works with a joyous lucidity1 the spirits are high and the step elastic and vigorous4 ,on another day the mind is turbid2 it works slowly and hesitates in reaching decisions2 one is listless and lacking in physical energy4 ,on both days one may be in a perfectly normal physical and mental condition1 except for the effects of the weather4 ,under the direction of the writer1 comparison of the records of crimes of violence with the weather records1 by officials of the ,u4 ,s4 ,weather ,bureau1 showed a marked increase of crime of this sort during midsummer as against midwinter1 and the extremely hot summer showed more crime than the cool ones4 ,during recent years ,ellsworth ,huntington has made exhaustive and extremely valuable studies of the records of piece workers in factories and elsewhere from ,new ,england and the ,middle ,atlantic ,states down to ,florida and the ,gulf of ,mexico1 and also of the mental activities of the cadets at ,west ,point and ,annapolis1 and of the students in colleges1 as shown by their recitation markings4#d ,he has compared these records with the weather day by day and hour by hour and definitely shown a direct relation between variations in the meteorological conditions and human efficiency4 ,he finds that people's health and strength are greatest when the temperature falls to between #ef and #fj at night and rises to somewhere between #fh and #gb during the day4 ,he has determined the optimum1 or1 in other words1 the meteorological conditions best suited to man's health1 happiness1 and efficiency4 ,for mental activity the optimum temperature is much lower than for physical4 ,people's minds are more alert1 they reason with greater analytic precision1 they have greater confidence in their decisions and they are more optimistic1 when the temperature falls to about freezing at night and rises to #de or #ej during the day4 ,except for limited activities1 the most efficient man is the one in whom the mental and physical faculties are most perfectly cordinated4 ,broadly speaking1 this agreement may be best accomplished during times when the daily temperature ranges between #de and #fe4 ,excessive humidity in midsummer--eighty per cent4 or over--is harmful and adds enormously to the death rate2 on the other hand1 some of the worst colds may come from extreme dryness in summer4 ,it may be found feasible to dry the air in sleeping and living rooms in summer when the humidity is too high1 by closing the apartment and forcing the air over or through calcium carbide or melting ice and salt4 ,when the air is kept at #fe to #gj per cent4 humidity in winter one will feel comfortable in a much lower temperature--about #fh--than when the air is extremely dry1 as it usually is in the average living apartment4 ,with a relative humidity of #cj to #dj per cent4 which one now often finds in warm houses in winter1 the temperature may be forced up to #ge or over and still one may feel cold1 because of the rapid evaporation from the pores of the skin1 and the cold created inside the clothing by the heat lost in the process of evaporation4 ,bear in mind that perspiration is going on at all temperatures1 even if one is unconscious of the fact4 ,in the most populous portions of the ,united ,states there are two periods of maximum efficiency and two of minimum each year4 ,let us consider that wonderful region including southern ,new ,england1 the ,middle ,atlantic ,states1 the ,ohio ,valley1 and westward to the ,rocky ,mountains4 ,again referring to the records of ,huntington we find that human energy is greatest in ,october2 the output of factory1 mine1 and counting room is greater per man than at any other time of the year and the product of mental effort is greater and of higher quality4 ,likewise disease is less and the death rate the least4 ,from this time there is a loss in energy until ,january or ,february1 when vitality and efficiency may have dropped twenty to thirty per cent4 ,then there is a gain until ,may or early ,june1 when the conditions of health and efficiency are nearly equal to the most favorable time of the year in ,october4 ,again there is a loss until the middle of ,july1 when a second minimum occurs2 physical and mental energy are at a low ebb and the death rate is high4 ,diseases are not quite the same as in winter1 as stomach troubles are more common than colds4 ,the hotter the summer and the colder the winter the less favorable are the conditions of human existence4 ,as there is a certain optimum beyond which diurnal and annual range of temperature cannot increase without a loss in energy1 so there is a limitation in latitude beyond which the favorable climatic conditions decrease as one goes northward or southward4 ,as an example1 ,canada and northern ,maine have but one unfavorable period1 which is the entire winter4 ,the people of these regions are at their greatest potential ,july to ,september1 after which they show a steady decline as the severity of the northern winter draws upon their vitality1 until in ,january and ,february their minimum is below that of regions considerably farther south for the same period4 ,from the most favorable climatic area in the middle latitudes--and the entire world possesses none more favorable or of greater extent than that possessed by the ,united ,states--the loss of health and strength due to the enervating effects of heat1 high humidity1 and insufficient temperature oscillations increases as one goes toward the equator4 ,in ,florida and the southern third of the ,gulf ,states there is but one favorable period1 the short winter4 ,the enervating conditions still further are manifest as one proceeds farther southward4 ,in the 8,principles of ,human ,geography01 it is stated that 8in ,central ,france and ,southern ,germany the seasonal variations in health and strength are much the same as in ,boston1 ,new ,york1 ,cleveland1 and ,detroit4 ,that is1 people are most healthy and strong in ,october and early ,november and again in ,may and early ,june1 while they are weakest and most subject to disease in ,january1 ,february1 and early ,march1 and again in ,july and ,august4 ,farther north1 for example1 in ,scotland1 ,scandinavia1 and ,finland1 the summer is the best time of the whole year and the winter the worst4 ,to the south1 on the contrary1 in ,italy1 ,spain1 and ,greece1 the harmful effect of the winter decreases and that of summer increases1 until finally on the south side of the ,mediterranean the winter is much the best time of the whole year1 while the long summer greatly diminishes the people's efficiency and increases disease and death40 ,as the highest mental activity is coincident with temperatures lower than those that induce the greatest physical energy1 it naturally follows that in the ,ohio ,valley1 southern ,new ,england1 and the ,middle ,atlantic ,states the mental worker is at his maximum in ,november instead of ,october1 and ,april instead of ,may4 ,illustration3 ,,chart #ag4--,,map ,,of ,,climatic ,,energy4 7,huntington and ,cushing47 ,chart #ag shows how human energy would be distributed over the earth if it depended on climate alone4 ,it is remarkable how almost exactly it agrees with what we know to be the distribution of the great political power4 ,japan is meant to be included in the region of high power1 but the scale of the chart is too small to make this plain4 ,illustration3 ,,chart #ah4--;,,density ,,of ,,population ,,in ,,the ,,united ,,states1 #aiaj4 ,from the time when man began to lose his tribal instinct and to assume national consciousness1 in ,egypt1 the ,mesopotamian ,valley1 and the region between the ,caspian ,sea and the ,persian ,gulf1 he has been founding empires of more or less enduring nature1 and with few exceptions has builded towards the west1 in the face of the prevailing winds4 ,the center of ,empire has steadily migrated along the paths of greatest storm frequency4 ,examine ,charts #aj1 #aa1 and #ah and note the relation between density of population and the closeness of the storm tracks4 ,the figures at the center of each brace indicate the number of storms that originated in the region of the brace during a ten-year period1 and the lines leading from the brace show the tracks followed by the centers of the storms4 ,bear in mind that each storm covered an area of from five hundred to one thousand miles in diameter1 that it was a vast rotating eddy in the atmosphere1 and that its center of rotation followed one of these storm tracks4 ,twelve storms came from the ,west ,indies during these ten ,augusts1 fifty-seven from the ,rocky ,mountains and none from the ,pacific ,ocean2 while in the ten ,januaries none came from the ,west ,indies and but twenty-two from the ,pacific ,ocean4 ,but the point to which your attention is directed is that1 no matter what the origin1 the tendency of each storm was to move towards the ,ohio ,valley1 ,pennsylvania1 ,new ,york1 ,new ,jersey1 and ,new ,england4 ,this tendency gives to these regions the most frequent changes in weather1 with alternations of sunshine and clouds1 and changes in temperature and air pressure--conditions essential to the development of the greatest human potential4 ,here population is the densest1 civilization the highest1 and the products of man's brain and hand greater and more diversified than elsewhere in this country1 and probably than elsewhere in the world4 ,the ,united ,states is abundantly blessed1 for nearly its entire area is under the influence of high atmospheric potential4 ,only the region adjacent to the ,gulf of ,mexico and the southwest is outside of the favored area1 and here the conditions are charted as medium1 and not poor2 at least not poor in comparison with many more purely tropical regions4 ,to-day the ,empire of ,human ,greatness is centered over the ,united ,states1 that is to say1 greatness as expressed in material wealth1 population1 and homogeneously knit political institutions4 ,will it continue its westward migration1 or will it remain here indefinitely for the working out of a civilization higher than yet has come to any of the nations of the past1 or to other of those of the present8 ,so far as atmospheric activities have to do with its translation from place to place1 we may derive comfort from the fact that storm tracks do not cross the ,pacific ,ocean as freely as they do the ,atlantic4 ,in fact our ,rocky ,mountains are a barrier to the passage of summer storms 7,chart #aj7 and a reference to ,chart #aa will show that of ninety-five winter storms that crossed our continent during the ten ,januaries of which the chart is a record only twenty-two came into our area from the ,pacific2 and we know that these twenty-two largely originated off our coast somewhere between ,hawaii and the ,aleutian ,islands4 ,let us hope that the center of earthly power has reached the end of its westward journey and that here it shall remain1 always to exercise a just and beneficent influence upon the less favored portions of the earth4 ,enough has been said to indicate that climate is nearly as important to animal life as it is to the vegetable existence1 and that a cold climate1 if it be not so extreme as to limit the production of cereal crops1 and has frequent changes in temperature1 pressure1 sunshine1 and cloud1 favors the development of hardy and resourceful races of men2 in fact1 that no dominating race can exist without such stimulating conditions of climate4 ,,chapter ,,xiii ,,has ,,our ,,climate ,,changed8 ,,popular ,,opinion ,,erroneous1 ,,as ,,there ,,is ,,no ,,change ,,within ,,the ,,period ,,of ,,an ,,individual ,,life1 ,,but ,,momentous ,,changes ,,have ,,occurred ,,since ,,the ,,beginning ,,of ,,the ,,christian ,,era ,one of the hallucinations entertained by nearly every adult person is that the climate has changed since he was young4 ,no matter what the scientists may say1 he knows that it has changed4 ,fifty years ago did he not trudge to school for months every winter in snow knee-deep8 ,have not the old swimming holes in the brook dried up8 ,yes1 he is a positive witness to an affirmative answer4 ,even the river of his boyhood1 whose broad expanse he conquered in a swimming contest at the tender age of ten--as he views it after an absence of a quarter-century--has dwindled to little more than a creek1 across which one easily may hurl a stone4 ,talk to him about no change in climate4 ,he's been right on the spot1 and knows4 ,for all this1 there has been no change during the lifetime of this man2 nor has there ever been during the life period of any individual4 ,mutations1 to be sure1 are going on all the time1 but they are so minute that they do not accumulate a measurable quantity except in periods of hundreds or thousands of years4 ,it is not the climate that has changed2 it is the man4 ,the natural action of the stream may have filled the swimming holes2 or the stream may have entirely disappeared through much of the contiguous area being brought under cultivation and the water that formerly supplied its flow being utilized in the production of cultivated crops1 which actually make use of as much if not more rainfall than the forest that formerly lined its sinuous banks and covered the near-by lowland4 ,and then1 snow knee-deep to a boy of ten hardly comes up to the ankles of a man of six feet two4 ,again1 no one can remember the climate of his boyhood2 he cannot carry the average in his mind2 all that he can remember are a few instances of unusual conditions which because of their unusual character left an impress upon his mind4 ,the river is just as wide as it ever was during the period of his lifetime1 or that of his father1 or of his grandfather2 but he has lived on the broad ,mississippi for many years1 and when he goes back to the scenes of his youth1 his concept of what constitutes a river has undergone a revolutionary change since he left the parental roof to go forth and conquer the world4 ,an examination of the personal papers of ,thomas ,jefferson1 in the ,state ,department at ,washington1 by an official of the ,weather ,bureau1 revealed a number of most interesting incidents in connection with the weather observations made by the author of the ,declaration of ,american ,independence4 ,he says3 8,a change in climate is taking place very sensibly4 ,both heats and colds are becoming much more moderate within the memory of even the middle-aged4 ,snows are less frequent and less deep4 ,they do not often lie below the mountains more than one1 two1 or three days1 and very rarely a week4 ,the snows are remembered to have been more frequent1 deep1 and of long continuance4 ,the elderly inform me that the earth used to be covered with snow about three months in every year40 ,but ,jefferson and his neighbors were mistaken4 ,never during the period of authentic history has the snow covered the ground in ,virginia an average of three months per year1 or three months for a single year4 ,these old inhabitants were like those of to-day1 who remember only the abnormalities of climate of twenty-five or fifty years ago1 and in comparing the unusual conditions of long ago with the average of the present time they are deceived4 ,i have known intelligent and well-meaning persons to declare that they knew from personal recollection that the climate of their particular places of residence had changed since they were young2 that they had stable landmarks to show that the streams were drying up1 the rainfall growing less1 and the winters becoming milder1 notwithstanding the fact that carefully taken observations of temperature and rainfall for each day for over one hundred years right at their places of abode showed no change in climate4 ,we have a continuous daily record for one hundred years at ,new ,bedford1 ,massachusetts1 nearly as long records at several other places1 and numerous records for over half a century4 ,from these we learn that there has been no definite change in climate in this country during the past hundred years4 ,there have been variations1 such as an excess or a deficiency of rainfall over a considerable area1 that have persisted for several years at a time2 but in each case the conditions would ultimately come back to normal1 or more often to an extreme of the opposite tendency to what had obtained immediately before4 ,in sections where the rainfall in bountiful years is barely sufficient for good crops1 the people in the past have been prone to consider that the amount that they receive during the periods of excess is that which normally is due them1 and thus to be unprepared for the dry periods that statistics tell us must certainly come4 ,the matter of change of climate is most important to our sub-arid ,west1--to the western parts of ,texas1 ,oklahoma1 ,kansas1 ,nebraska1 and the ,dakotas4 ,some years ago1 when the tide of emigration was strong into these regions1 there were several years of more than the average rainfall4 ,the coming of population and the coming of extra rainfall were accidentally coincident1 but that fact was probably responsible for the popular belief that civilization brings an increase in precipitation2 that the breaking of the virgin soil1 making it more permeable to the absorption of moisture2 the planting of trees and the growth of crops1 restricting the run-off2 the roots of the new vegetable life drawing up the moisture from below the surface of the ground and transpiring it to the air through the leaves of plants2 the enormous quantities of water vapor ejected into the air by the combustion necessarily incident to a considerable population1--all had combined to increase the rainfall and render the sub-arid plains more responsive to the efforts of the husbandman4 ,no one can fail to regret that this theory is not founded upon fact4 ,but a moment's thought by the scientist will indicate to him that the volume of air is so great1 and under the heat of the growing period its capacity for moisture so enormous1 that the addition of vapor of water by the processes herein described1 great though it be1 is ineffectual to appreciably change the amount of the rainfall that nature beforehand had ordained should be precipitated4 ,the size of continental areas1 the height and the trend of mountain ranges1 the proximity of large bodies of water1 and the direction of the prevailing winds are the factors that determine the amount of the precipitation of a region4 ,against these the puny efforts of man1 stupendous though we think them to be1 are entirely unavailing4 ,as an illustration3 ,if the ,rocky ,mountains were as old as the ,appalachian ,chain1 and if they were eroded down to the height of the latter system1 the winds from the ,pacific ,ocean1 when they are drawn inland by the cyclonic storms of the ,rocky ,mountain plateau1 or of the ,mississippi ,valley1 instead of depositing their moisture on the west slopes of the first range of mountains1 would carry the water vapor of the ,pacific clear to that place in the ,mississippi ,valley where it would meet the moisture drawn by the same storms from the ,gulf of ,mexico and the ,atlantic ,ocean4 ,this will appear clear when one understands that cyclonic storms1 such as are continually passing across our continent in periods of about three days each1 may embrace in their eddy-like circulating systems areas one to three thousand miles in diameter1 in which the winds from all directions spirally flow towards the center of the cyclonic system and the system itself is moving eastward4 ,the water vapor exists as a separate atmosphere from oxygen and nitrogen4 ,it is screened off from the interior of continents by mountain ranges because it is condensed and precipitated as rain or snow at only moderate elevations4 ,the windward side of mountains may1 therefore1 receive torrential rains while their leeward sides are entirely without precipitation4 ,it follows that if the ,rocky ,mountains were lowered as described1 the entire ,united ,states would be green with rich vegetation and there would be no deserts anywhere within its broad boundaries4 ,also1 if the ,appalachian ,range were as high as the ,rocky ,mountains--as it may have been at one time--and if it extended around the ,gulf of ,mexico as well as up through our ,atlantic ,coast ,states1 the vaporous atmosphere of the ,atlantic ,ocean and of the ,gulf of ,mexico would be prevented from entering the interior of the continent1 and the power that to-day stands as the greatest bulwark of civilization would not exist4 ,there would be but a narrow fringe of vegetation upon its east and its west coasts2 the interior1 with its vast cotton and cereal plains1 would be a barren waste4 ,but to revert for a moment to ,jefferson4 ,he took his thermometer to ,philadelphia when he proceeded there on a mission that would have caused any less serene and courageous spirit to forget all the small details of life4 ,when the debates upon which hung the fate of a nation and1 in fact1 the lives of those that participated1 were in progress1 he coolly hung his thermometer on the wall and noted down its readings4 ,those historians who have described the intense heat in ,independence ,hall on the ,fourth of ,july1 #aggf1 were mistaken1 as will be shown by reference to his observations1 the early and the late ones of which doubtless were made at his lodgings4 ,they are as follows3 #f ,a4,m41 #fh2 #i ,a4,m41 #gb2 #a ,p4,m41 #gf2 and #i ,p4,m41 #gc4 ,jefferson had one of the only two barometers in this country at that time4 ,james ,madison 7the ,bishop1 not the ,president7 had the other4 ,they took readings at the same hour of the day for a considerable period of time1 and ,jefferson discovered that changes in the pressure of the air always began on his instrument a few hours before they did on his friend's instrument a couple of hundred miles to the east of him4 ,he came near discovering the fact that no matter what the direction of the wind1 storms almost universally move from the west toward the east4 ,when the ,british captured ,washington they also raided ,monticello1 ,jefferson's home in ,virginia1 and they destroyed his barometer4 ,it has been said that he was as much distressed over the loss of his special instrument of science as he was over the burning of the ,national ,capitol4 ,in 8,descriptive ,meteorology0 7,appleton71 the writer expressed doubt that there had been important changes in climate within the period of authentic history1 but recent researches cause him to change his opinion1 for the evidence now seems almost conclusive that marked changes have occurred4 ,the powerful kingdoms of ,sumeria1 ,babylonia1 ,assyria1 and ,persia1 each ruling many centuries and dominating all or a large part of the vast region from the ,persian ,gulf to the ,caspian ,sea and westward to the ,mediterranean and ,egypt1 covering in their various reigns some four thousand years before ,christ1 could hardly have built their many great cities1 supported their numerous millions of population1 and developed the trade and commerce that was theirs with the climatic conditions as they exist to-day4 ,as late as the opening of the ,christian ,era1 ,palmyra1 in ,syria1 had a population of from one hundred and fifty thousand to two hundred thousand people1 was opulent and adorned with a comparatively high civilization4 ,to-day we see the wreckage of its vast aqueduct and irrigating systems1 which are unable to gather enough water to wet their well-constructed walls1 and a few hundred people eke out a miserable existence where once was a metropolis teeming with life under luxurious conditions4 ,the same picture is shown in more or less relief throughout the greater part of the region that once maintained the greatest empires of antiquity4 ,but we must not assume that such dry and nearly barren conditions are to continue forever2 rather are we to imagine that within a cycle of a few thousand years this region may have a rebirth of abundant vegetation and again throb with the pulsations of abounding life4 ,the record inscribed by the waters on the abandoned and the submerged shores of inland lakes and seas in the ,rocky ,mountains1 and on the shores of the ,caspian ,sea and other waters1 is easy to read4 ,it shows several great oscillations of climate in the ,united ,states and the most civilized portions of the world since the birth of ,christ4 ,for some time before and for several centuries after the beginning of our era there was a wet period4 ,the ,caspian ,sea stood some one hundred feet higher than now and an abandoned beach and a clearly marked shore line show that ,lake ,owens1 in ,california1 on the east side of the ,sierras1 existed at a level nearly two hundred feet higher than now4 ,there was an abundance of water to irrigate the ,holy ,land1 and although the center of dominating human power had long since passed in succession ,babylon1 ,assyria1 ,persia1 ,greece1 ,macedon1 and was working its way towards the ,atlantic1 the ,mesopotamian ,valley was abundantly fruitful4 ,then1 for six or seven hundred years1 with short-period variations of from thirty to fifty years1 the world inhabited by civilized man and large areas in the temperate zone not yet civilized1 grew drier4 ,the ,caspian ,sea fell to a lower level than it now maintains1 for the ends of great walls1 constructed to keep out barbarians1 and other evidences of the handiwork of man1 are now many feet below the surface of the water4 ,this is the driest time known to history4 ,ellsworth ,huntington of ,yale1 acting under the auspices of the ,carnegie ,foundation at ,washington1 made an examination of many of the stumps of the big trees of ,california1 ranging in age from one to four thousand years4 ,the thickness of each ring of annual growth is a legible record of the wetness or the dryness of the year4 ,one would hardly think of these towering giants of the floral kingdom as being both thermometers and rain gauges1 accurately measuring and recording the dry-hot and the wet-cold periods for thousands of years1 and now at the end of their majestic careers revealing the hidden secrets of past ages4 ,huntington and ,cushing1 in 8,principles of ,human ,geography01 say3 8,the rings dating from the time of ,christ are thick and indicate that at that time1 when ,palmyra had an abundant supply of water1 when ,owens ,lake overflowed and there was high water in the ,caspian ,sea1 the big trees also had plenty of water and grew rapidly4 ,six or seven hundred years later1 when ,palmyra was abandoned and when the ,caspian ,sea stood fifteen or twenty feet lower than at present1 the trees formed only narrow rings1 because the climate was dry4 ,the way in which the growth of the trees has varied is shown in ,figure #cj4 ,the high part of the curve indicates abundant rainfall4 ,the black shading at the bottom indicates periods of comparative aridity40 ,illustration3 ,,fig4 #cj4--;,changes in ,climate in ,california during the ,christian ,era4 ,black shading indicates ,drought4 ,since the extensive system of observations by the ,weather ,bureau was inaugurated1 some fifty years ago1 it has been revealed to us that frequently the ,ohio ,valley would suffer a deficit in rainfall that would persist for periods as great as five or six years1 while ,new ,england and the ,south ,atlantic ,states1 or other large areas of the country1 had an excess4 ,this is an illustration that excesses in one part of the country were balanced by shortages in other parts that occurred at the same time4 ,but the long-period oscillations in climate that are measured in hundreds of years instead of tens--these changes seemed to have occurred simultaneously in the middle latitudes of ,europe and ,america4 ,these changes were simultaneous in an east and west direction4 ,now we have evidence of such long-period changes in a north and south direction which were simultaneous1 but of an opposite character1 indicating that during the ,christian ,era the eastward track of storms has oscillated northward and southward4 ,this would account for the occurrence of dry and of wet periods simultaneously throughout the vast stretch of territory between southern ,california and the ,caspian ,sea4 ,in ,guatemala1 ,yucatan1 and other ,central ,american countries there are ruins of cities and the evidence of an agriculture and a civilization that could not have been established with the torrential rains and jungle growths that now prevail in those regions4 ,during the centuries when the big trees of ,california were receiving a large rainfall and making a thick annual growth1 especially about the beginning of the ,christian ,era1 because of a northward shifting of the climatic zone1 the precipitation in ,yucatan and ,guatemala had so diminished as to leave only the amount of rainfall that could be economically employed in agriculture and in the rearing of great cities2 and then1 with a southward migration of the rain belt1 these cities were suffocated with excessive precipitation1 agriculture rendered impossible1 and their temples and palaces buried beneath the gloom of a tropical growth4 ,if we are to reason from the records of the past it seems highly probable that at least the middle latitudes of the ,northern ,hemisphere are slowly passing out of a dry period that has prevailed for the past two hundred years or more4 ,for several hundred years all the great glaciers have receded1 but we should not expect such recession to continue indefinitely4 ,geology furnishes abundant evidence that great changes took place in the climate of the earth during the prehistoric ages2 that there were several glacial periods1 the last occurring during pleistocene times1 somewhere between twenty and fifty thousand years ago1 and that there were intervals between the culminations of the ,ice ,ages of probably fifty thousand to one hundred thousand years4 ,between these long winters1 that have meant death and desolation to much of what are now the most civilized portions of the earth1 there have been warm periods of thousands of years' duration4 ,fossil remains show that regions far north1 now covered with perpetual ice1 once supported a luxuriant flora and fauna1 and many regions in the temperate and equatorial zones that are now deserts were once overgrown with forests and teeming with animal life4 ,the fundamental thing of the cosmos is change--birth1 growth1 maturity2 then decline1 senility1 death1 decay1 disintegration2 and always a renaissance1 or new birth4 ,energy and life seem to be eternal1 but ever undergoing change4 ,the ,great ,ice ,cap may again cover ,new ,england1 the region of the ,great ,lakes1 and flow southward to the ,ohio ,river1 but the change will be so gradual1 if it does come1 that there will be no great cities to be ground beneath the feet of the boreal monster2 cold that will precede the ice cap will destroy them and they will be buried beneath the dust of accumulating ages before their icy tombstone is erected4 ,then the healthful and invigorating climate of the north part of our country will be transferred to the region of the ,gulf of ,mexico4 ,civilization will and must migrate with the shifting of the climatic belts4 ,because these changes cannot possibly concern us personally1 we have almost neglected the study of the great forces that silently yet most persistently are at work altering the conditions under which future man must live and work out the destiny of coming generations4 ,effects of ,forests on ,climate and ,floods4 ,next to the fallacious belief in a change of climate during the life of an individual there are few if any errors that have gained such wide acceptance as a belief that the cutting away of the forests has caused a marked change in climate and especially in the frequency and intensity of floods and droughts4 ,the writer shared in the mistake with regard to the influence of the forests in restraining run-off and augmenting floods1 until compelled by an order of the ,congress of the ,united ,states to prepare a report on the floods of the nation that had occurred during the time of the gradual reduction of the forest areas4 ,dividing into two equal periods the forty years for which the ,weather ,bureau has comprehensive records of the rainfall upon the catchment basins of the ,tennessee1 the ,cumberland1 and the ,ohio rivers1 and for which it has records of the height of the rivers1 contrary to his belief1 he found that the high waters were no higher with a given rainfall1 the floods of no longer duration1 nor the low waters of summer lower1 during the last half of the period than during the first half4 ,it is now pretty generally conceded by hydraulic engineers that the broken1 permeable soil of the husbandman1 frequently stirred by cultivation a part of the year and filled with countless billions of the tiny water-absorbing rootlets of the grasses and the cereal crops during the remainder of the annual period1 is equally as good a conserver of the rainfall as the forests themselves1 even if it is not better4 ,some years ago the writer was delivering a series of ,chautauqua lectures4 ,he arrived at ,devil's ,lake1 ,north ,dakota1 and found that the ,chautauqua amphitheater was on the banks of ,devil's ,lake1 once bordering the town1 but now receded to a distance of five miles and confined to a narrow valley4 ,in driving from the city to the lecture hall he remarked to his escort that they seemed to be traveling along the bottom of an ancient lake4 ,his companion said1 8,yes1 a lake1 but not an ancient one4 ,fifty years ago ,i used to dive off a springboard right there in front of the railroad station40 ,in the course of his lecture the writer referred to this incident and told them that1 contrary to their belief1 their climate had not changed1 that fifty years ago they sold their old lake to some gentlemen in ,chicago and that they had been selling it over again every year since2 that the former compact surface of the virgin prairie resisted the penetration of the rainfall1 or at least only slowly absorbed it1 and allowed it to collect in the depression adjacent to the city2 but now1 in the broken1 permeable soil of the farmer it was taken up by millions of tiny rootlets and the hand of the ,great ,alchemist had transformed their lake into wheat1 the sale of which was responsible for the presence of the speaker on the platform of a largely-attended ,chautauqua4 ,the lake had gone never to return unless the region were again to become the haunt of the buffalo and the prairie dog instead of civilized man4 ,the rainfall was the same1 but it was now being utilized for the benefit of mankind4 ,in this problem of rainfall1 floods1 and the forests1 most persons assume that when the forest is cut the land is at once denuded of vegetation4 ,on the other hand a second growth will effectually shade the soil within a few months or a few weeks after the large trees are removed1 and if the land is cleared and rendered fit for the plow1 growing crops take the place of the forest-covering the greater portion of the time4 ,there is an abundance of reasons for the protection of our diminishing forests and for the creation of new forest areas without assigning to the forests functions that they do not exercise4 ,the covering of an area by a great city1 a village1 a forest1 a barn1 or a tent modifies the climate of the particular area covered so long as the covering remains1 but there is no appreciable climatic effect a few feet above the surface of the earth between a forest and a field of grain4 ,the climate of a region like the ,american continent is controlled fundamentally by the great oceans that wash its shores1 by the trend of its mountain systems and their height1 and by the direction of its prevailing winds4 ,the vast vaporous atmosphere that flows inland from the ,atlantic ,ocean to the foothills of the ,rocky ,mountains1 deluging our cereal plains with its life-giving precipitation will continue its pluvial generosity without any heed whatever to the puny scratchings of man upon the surface of ,mother ,earth4 ,nothing that man can do will intensify drought conditions on this continent or augment the volume of floods4 ,it is time that we return to sanity in considering this matter instead of being frightened by the dire forebodings of well-meaning but purely visionary enthusiasts1 no matter how noble their aspirations may be or how self-sacrificingly they have consecrated themselves to the redemption of humanity4 ,it is certain that forests restrict the flow of moderate falls of rain1 but they do not restrain the flow of flood waters1 because1 surprising as it may seem to one who has not tested the matter1 floods do not occur until after all surfaces1 open fields and forests alike1 have become saturated1 and then the run-off of the two surfaces is equal4 ,,chapter ,,xiv ,,climates ,,for ,,health ,,and ,,pleasure ,,one',s ,,life ,,would ,,be ,,prolonged ,,if1 ,,like ,,the ,,birds1 ,,one ,,could ,,migrate ,,annually ,,with ,,the ,,temperature--,,christmas ,,in ,,many ,,climes--,,the ,,hottest ,,and ,,coldest ,,places ,,in ,,the ,,world ,from what has gone before it is apparent that the regions of the earth where man is at his best estate1 so far as climate can determine his environment1 may be broadly defined in this country as southern ,new ,england1 southern and central ,new ,york1 the ,middle ,atlantic ,states1 the ,ohio ,valley1 the southern ,lake ,region and westward to the middle of ,kansas and ,nebraska2 in ,europe it includes the ,british ,isles1 ,france1 ,switzerland1 extreme northern ,italy1 ,austria1 ,germany1 ,belgium1 ,holland1 and the extreme southern parts of ,norway and ,sweden4 ,but in none of these regions is the climate equally good during all seasons4 ,in fact there are two short seasons in each year when it is debilitating4 ,the great majority of the people1 like galley slaves chained to their oars1 must remain in the same place throughout the year1 others may have a vacation of several weeks1 and still others are free to change their location as often as fancy calls them4 ,the latter might well learn from the birds1 and by migrating with the temperature1 going far north in summer and far south in winter1 maintain themselves throughout the entire year in the most perfect atmospheric conditions for health1 happiness1 and long life4 ,many a man of fifty1 having accumulated enough to modestly supply his wants1 could add ten to thirty years to his life1 or might even double the period of his existence1 by ceasing to strive after riches1 and by giving himself up to a healthful movement about this beautiful world4 ,his principal companions should be good books1--the study of which will enlarge his mental horizon and increase his capacity to see1 comprehend1 and enjoy1 and fit him to speak1 act1 and think in ways that will inure to the public good4 ,if he has not had the benefits of a college education1 now is the golden opportunity to read1 and have pleasure in the reading1 popular books on ,geology1 ,botany1 ,biology1 ,astronomy1 and ,physics1 and to become familiar with the history of his own country and of the world4 ,it need not be a period of idleness but one of beautiful growth and of appreciation of the wonders of creation4 ,and thus will his spirit be lifted up and fitted for a higher realm of existence in the world to come4 ,to those who must remain at home during heat spells1 the advice is given to close not only the shutters but the windows on the east side of the house during the forenoon and do the same on the west side in the afternoon4 ,the best night's sleep will be gained in a room facing north on any floor that is not next the roof2 this room will be cooler if it is protected by another room on its east and one on its west side4 ,long ,life in the ,open ,air and the ,sunshine4 ,it is difficult to decide which most conduces to health and longevity3 cheerfulness of mind and kindness of thought1 or life in the open air and in the blessed sunshine4 ,if one can enjoy both of these beneficent conditions they should live as long as they desire to remain on earth4 ,most people live as long as they deserve to live4 ,it has facetiously been said that old age is a bad habit4 ,the writer is disposed to agree with the humorist4 ,certain it is that few persons who believe in the limitation of life to three score and ten ever live beyond that period1 while one should be possessed of a sound body and a superior mind at that age1 with just anticipations of a third of a century of usefulness and happiness yet to come4 ,as a man thinketh1 so is he4 ,we are just beginning to comprehend something of the wonderful power with which the ,creator has invested us in the development and the care of our bodies4 ,anger1 hatred1 malice1 jealousy1 selfishness1 fear1 and worry create poisons that may bring on disease and death1 but they certainly create a morbidity in the body that shortens life4 ,sunshine destroys molds1 bacteria1 and other enemies of the human race that lurk in the darkness4 ,it strikes dead the tubercle bacillus1 which is such a scourge to mankind4 ,its remedial power comes largely from invisible light--the ultra-violet and the supra-red rays4 ,you are blind to these rays but your skin and blood are not2 they need the sunshine to give them vitality--not quack medicines or medical tonics for which1 through the venal partnership of the ,press1 millions of the afflicted are induced not only to part with the money so much needed by their families and themselves1 but to aggravate their sufferings4 ,the sunshine of a high region is beneficial to those ill with coughs1 colds1 bronchitis1 tuberculosis1 anmia1 or other wasting diseases1 because the upper altitudes are rich in many rays that are beneficial1 some of which are absorbed by the higher air and do not penetrate to the earth1 or only reach the earth in minute quantities4 ,there on the mountain the sun's rays are unpolluted by the dust and the bacteria of lower levels and the cities4 ,but one does not need extreme altitudes4 ,two to three thousand feet may be sufficient4 ,mountain and ,sea ,air and the ,injury from ,over-bathing4 ,the seashore is properly a great national playground during the heat of summer4 ,evaporated spray leaves a trace of salt in the air which1 with the salt of the ocean1 seems to be beneficial to many4 ,likewise there is no condition of life that is not benefited by the pure air of the wooded mountains4 ,those of moderate vigor may build up and maintain high vitality by continuous bathing in the cool1 pure waters of mountain lakes and streams1 but to many daily swimming in either fresh or salt water1 except that it be for a mere dip and right out again1 that is so cold as to be painful to the delicate sensations of the skin1 is extremely debilitating to all bodily functions4 ,be moderate4 ,how to ,find the ,climate ,you ,seek4 ,at sea level in the tropics heat and moisture combine to produce great physical discomfort4 ,but even under the equator it is possible to escape the tropical heat of low levels by ascending four to six thousand feet1 as can be done in some places in ,porto ,rico and ,cuba4 ,most of the capitals of ,south ,american countries are located at altitudes of five to ten thousand feet2 and ,brazil is planning to abandon her capital at sea level and move the administrative machinery of government from the splendid city of ,rio de ,janeiro to a mountain location in the interior4 ,any region of the ,alleghany system of mountains above a thousand feet elevation possesses climatic conditions of therapeutic value4 ,illustration of this fact is seen in the success of the noted sanitaria in the ,adirondacks1 and in the mountain regions of ,north ,carolina and ,virginia1 and in the northern part of ,new ,england4 ,these sections are especially frequented by persons suffering from pulmonary diseases1 or from nervous exhaustion1 many of whom find not only relief but cure4 ,cool and healthful conditions of temperature may be found during the summer along the ridges and on the peaks of the entire mountain system that extends from ,north ,carolina northward through ,virginia1 ,pennsylvania1 ,new ,york1 and ,new ,england4 ,the advice of one's physician should be sought1 if one is ailing1 before determining between the seashore and the mountains1 but in general those suffering from diseases of the respiratory organs are better located in the high levels1 remote from the humid air of the ocean4 ,in winter ,bermuda1 ,florida1 ,porto ,rico1 ,cuba1 the southern part of the ,gulf ,states1 much of ,southern ,california1 and ,hawaii have balmy climates that permit of outdoor life without temperatures too high to be comfortable4 ,hawaii and ,bermuda have mild climates not only during winter but throughout the entire year4 ,the ,riviera on the ,gulf of ,genoa and the beautiful ,lake region of ,italy enjoy the balmy air of the ,mediterranean and are protected from the cold winter winds by the ,alps4 ,from ,october to ,may that portion of the ,rocky ,mountain plateau that includes ,arizona1 ,new ,mexico1 and the northern interior of ,old ,mexico has one of the finest climates in the world for those afflicted with pulmonary diseases1 as the sunshine is abundant and the day and night temperatures such as to permit an almost continuous out-of-doors existence4 ,but the heat and the extreme dryness of the air in ,june1 ,july1 ,august1 and the first half of ,september is irritating to the nerves and debilitating in general4 ,fortunately1 when the conditions are not favorable in the extreme southwest part of the country1 they are at their best in the mountains of the ,middle ,atlantic ,states and ,new ,england1 which offer to the pleasure or the health seeker a cool1 pure air unsurpassed by any other region of the earth4 ,for an all-the-year climate for the health seeker1 it only can be said that the ideal conditions do not continue at any place throughout the entire year4 ,possibly it is well that it is so1 as a change may be beneficial for no reason except that it is a change4 ,there is one great caution ever to be borne in mind1 and that is that the health seeker must not continue or repeat the same unhygienic life in his new climate that brought on the disease in the old4 ,climate of ,cuba4 ,the climate of one tropical country may differ materially from that of another in the same latitude as a result of difference in altitude1 proximity to large bodies of water1 and position with respect to the prevailing winds4 ,cuba being in the region of the northeast trade winds1 more rain falls on the north side of its mountains than on the south side4 ,the temperature of the southeast coast is higher than it is on the northern and western coasts1 and the range of temperature everywhere between night and day is small1 rarely ten degrees and usually much less4 ,it therefore has a warm1 humid1 and monotonous climate1 except in the high levels of its mountains4 ,the winter tourist will find the conditions of the greater part of the island somewhat similar to those in the region of ,miami1 ,florida1 but warmer4 ,havana is not so hot as ,santiago4 ,the highest temperature ever recorded at ,havana is #aja and the lowest #ej4 ,a fairly pleasant temperature always can be found within a short ride to the mountains4 ,as in most tropical countries1 ,cuba has a dry and a wet season4 ,the rainy season is ,may to ,october4 ,in the early part of ,september1 #aijj1 over thirty-six inches of rain fell within thirty-six hours at ,santiago4 ,as a rule the precipitation is in the shape of heavy showers1 the clouds clearing as soon as the rain ceases2 the showers usually occur in the afternoon4 ,cuba1 in common with all the islands of the ,west ,indies1 occasionally is visited by destructive hurricanes2 these storms mainly are confined to the period ,august to ,october4 ,frequent terrific thunderstorms occur in summer4 ,climate of ,porto ,rico4 ,its mountainous character gives it a marked diversity of climate1 torrential rains falling on the windward side of its mountains1 while the leeward sides are comparatively dry4 ,the highest temperature in ,san ,juan since #ahgf is #aja and the lowest #eg4 ,in this city a cool breeze1 known as the 8briza01 adds to the comfort of the late afternoon and evening4 ,the wet season begins a month earlier than in ,cuba and lasts a month longer4 ,san ,juan is probably the most healthful city in the ,west ,indies1 but those reared in northern climates invariably suffer from its enervating influence after several years of continuous residence4 ,water is abundant1 there being some seventy rivers and over a thousand small streams4 ,the mountains are clothed in vegetation to their tops1 and frost of a killing nature is practically unknown in the island4 ,climate of the ,hawaiian ,islands4 ,much has been written about the charm of the ,hawaiian ,islands1 their mountains1 volcanoes1 tropical verdure1 and delightful climate4 ,it is indeed a garden spot1 and its soil and climate make it so4 ,nowhere in the islands does the temperature reach #ij at any time of the year1 while at ,honolulu1 the largest city and the capital1 a temperature lower than #fj is rarely experienced4 ,of course1 as one ascends the high mountains for which the group is noted1 much lower temperatures are encountered1 while snow is not infrequent near the tops4 ,july and ,august are the warmest months and ,january the coldest4 ,the climate is soothing and dreamy and doubtless would prolong the life of many who are aged and slowly passing to their end1 and that of others of low vitality but no organic disease4 ,most of the rain falls ,november to ,may1 but some falls in every month of the year4 ,at ,honolulu the amount is about that which falls in ,wisconsin1 but at a station in the ,kohala ,mountains one hundred and fifty-four inches have been measured as the rainfall for seven months1 and forty-two inches for one month1 the latter being a larger amount than the annual rainfall for the ,state of ,iowa4 ,climate of the ,philippines4 ,the highest temperature so far recorded at ,manila is #ajj and the lowest #fj4 ,it is therefore warmer than either ,havana or ,porto ,rico4 ,the hottest months are ,april1 ,may1 and ,june1 but the cool months are but a trifle cooler than the warm months1 the annual range of temperature being but three degrees4 ,the humidity is high at all seasons1 and therefore the heat is oppressive and debilitating4 ,the greater part of the rainfall of ,manila is from ,june to ,october4 ,some relief may be gained from the low-level heat by retreat to the mountains of some of the islands4 ,it will require several generations before the white man can become acclimated to this region4 ,the islands lie between latitude #f and #ah ,north4 ,white children born of ,american parents and raised there never will have the energy or ambition of their progenitors4 ,if it were not for the invigorating air of the mountain resort at ,baquio1 many ,american officials could not continue a residence in the ,philippines4 ,climate of ,bermuda in ,comparison with the ,popular ,winter ,resorts of ,florida and ,california4 ,it is a mistake to represent the climate of ,bermuda as one of balmy sunshine during winter months4 ,it has some glorious days1 but a large proportion are cloudy1 rainy1 cool1 and windy1 and too cold for comfortable or healthful bathing from the middle of ,december to the first of ,may4 ,and yet1 its climate is healthful as a whole for nine months of the year and more stimulating than is that of ,florida in winter4 ,if one wishes sunshine and sea bathing in midwinter1 it is better to go to ,palm ,beach1 ,st4 ,petersburg1 or ,miami1 ,florida2 but if one desires to have a moderately cool climate with a temperature of but little variation between midday and midnight1 and occasionally a day with sufficient warmth and sunshine to justify a dip in the ocean or in the many land-locked bays with which the islands abound1 one well may come to ,bermuda4 ,such winter clothing as one naturally would wear in ,philadelphia or ,washington is what one will need in order to be comfortable4 ,bermuda is no place for ,palm ,beach suits1 outing shirts1 and ,panama hats in winter4 ,many tourists are mislead by the advertisements of steamship lines and bring clothing which is suitable only for early fall and late spring4 ,from the first of ,november to the middle of ,may the author occupied a room on the ground floor1 facing the waters of ,hamilton ,harbor1 and only fifty feet from the shore line4 ,here the diurnal range of temperature is much less than at ,prospect ,hill1 where the ,government's observations are made4 ,from the middle of ,december to the middle of ,march1 a thermometer in this room sluggishly ranged from #fj at night to #fd during the day1 and days when the wind was high and rain falling--as occurs about one third of the time in winter--the thermometer would not vary a degree from #fj during the entire twenty-four hours4 ,during ,april the range each day was from #fh at night to #gj at midday1 and during ,november and ,may from #gj to #gf4 ,the selection of the best winter climate for health and for pleasure is so important that comparative data are here given of the most popular places that are easy of access to the people of the ,united ,states4 ,bermuda has a wind velocity much greater than that of any of the resorts named in the tables1 and its relative humidity is about that of ,florida4 ,the charm of ,bermuda is that the flowers bloom1 vegetables grow1 and the trees remain green the year round4 ,even though frequent short showers may fall each twenty-four hours more than half of the days during winter1 the soil is so porous that there is little or no mud1 and life is largely one of the open air1 with a winter temperature that conduces to activity2 in fact1 the temperature is such that one requires heavy clothing all the time if one is to sit inactive in the open4 ,there is neither frost1 fog1 nor malaria1 nor snakes4 ,bermuda lies #fff miles south of ,new ,york ,city and about #gjj miles due east from ,charleston1 ,s4 ,c41 and #bic miles from the southern edge of the ,gulf ,stream1 which1 if the truth must be told1 exercises no such influence on the climate of ,bermuda as highly colored advertising circulars would have one believe4 ,it is the great ocean1 upon whose surface the islands make the most infinitesimal dot1 that controls the climate of the ,bermudas4 ,the ,gulf ,stream1 wonderful phenomenon that it is1 is a sort of bug-a-boo to some who never have intelligently studied ocean meteorology4 ,travelers tell of the superheated atmosphere they encountered on crossing the ,stream1 and educators who should know better teach that the entire climate of ,europe is markedly influenced by it4 ,the fact is that there is no distortion whatever of the isothermal lines as they enter and leave the ,gulf stream in any region north of ,bermuda4 7,see ,chart #ad47 ,the climate of ,bermuda and of ,europe is controlled largely by the great ,atlantic ,ocean1 not by this small river of warm water1 which broadens out and loses its identity long before the coast of ,europe is reached1 and whose influence is soon dissipated in the vast expanse of ocean air4 ,the ocean has a great circulating system1 northward on the western and southward on its eastern side4 ,this circulation pushes the isothermal lines northward on one side and southward on the other4 ,the islands of ,bermuda rise some #ae1jjj feet from the floor of the ocean1 and project above the water to heights varying from #ej to #bfj feet above sea level4 ,like jewels nestling upon the bosom of a sub-tropical ocean these islands1 from one half to three miles wide1 are strung along so close that one almost can hop over from one to the other4 ,they lie in the form of a fish-hook2 from the hole where the line of the fisherman would be tied to the point of the hook is about twenty-six miles4 ,the topography is irregular and picturesque4 ,on land there are caves and grottoes and subterranean lakes4 ,january to ,may rose borders are abloom4 ,in ,april the oleander is showing pink and crimson along every roadside1 and the hedges hold these beautiful flowers for months2 at ,easter time lilies carpet the ground and perfume the air4 ,here morning glories have many forms and colors1 which1 with pendent bells1 climb wide-spreading cedar trees1 and wild passion flowers cover rocky cliffs4 ,the sea is so transparent that many feet below the surface the eye may follow the movements of marine life housed about by coral formations of strange devices4 ,the colors of the sea are as changeable as the opal4 ,over shallow bottoms the colors are delicate shades of light green1 over the shoals brownish hues1 and beyond the dangerous reefs1 which have sent many a sailor to his long home1 and behind which numerous pirates of old have taken refuge1 the waters vary from the light blue of the sapphire to deep green4 ,the prismatic colors are forever laughing and dancing to the eye of the beholder4 ,the shadow of a cloud1 a ripple of the surface1 a different angle to the fall of sunshine as the day advances1 deepen or brighten the tints through a wide range of color4 ,through the glass bottom of a boat one may look into the gardens4 ,rising from the bottom and waving gracefully with the movements of the waters1 like tree ferns moved by gentle zephyrs1 are purple sea fans and tall black rods4 ,beautifully colored fishes dart about1 or lazily bask in the sun that illumines their coral grottoes2 weeds of many colors2 green and scarlet sponges2 vegetable growths delicate in formation and brilliant anemones cling to ledges of rock that here and there are tinted with pink4 ,rival champions of the east and the west coasts of ,florida may fortify themselves by a study of the tables4 ,it may be noted that ,miami and ,tampa have the same midday temperature1 but that ,tampa has a greater range1 the night temperature on the average falling five degrees lower than ,miami2 also that ,tampa1 which can be taken as typical of ,st4 ,petersburg1 has but twenty-one rainy days on an average from ,december to ,march inclusive1 while ,miami has thirty-four4 ,bermuda has sixty-five days with rain during the period1 with much wind4 ,from these data one may select the climate that best suits him and he may know that the data are accurate and put forth by some one not interested in advancing the interest of one place over another4 ,no country in the world has more delightful and healthful climates for winter and for summer than can be found in the wide domain of the ,united ,states4 ,u4 ,s4 ,,weather ,,bureau ,,average ,,temperature1 ,,humidity1 ,,days ,,with ,,rain1 ,,cloudiness1 ,,and ,,wind ,,at ,los ,angeles1 ,california ,,data ,,jan4 ,,feb4 ,,mar4 ,,apr4 ,,may ,,june ---------------------------------------- ---------------- ,maximum #fd #ff #fg #gj #gb #gg ,highest maximum #hg #hh #ii #ajj #ajc #aje ,minimum #dd #de #dg #di #eb #ef ,lowest minimum #bh #bh #ca #cf #dj #df ,daily range #ba #ba #bj #ba #bb #bc ,relative humidity #fe #fi #fi #gb #gf #gf ,days with 4#ja or more rain #g #f #g #d #b #a ,percentage sunshine #fe #fh #fe #fh #fc #fi ,hourly wind velocity #e4a #e4c #e4c #e4b #e4b #e4j ---------------------------------------- ---------------- ,,data ,,july ,,aug4 ,,sept4,,oct4 ,,nov4 ,,dec4 ,,annual ---------------------------------------- ---------------------- ,maximum #hb #hb #ha #gf #gb #fg #gc ,highest maximum #aji #ajf #ajh #ajb #if #hi #aji ,minimum #ei #fj #eh #ec #dh #df #eb ,lowest minimum #di #di #dd #dj #cd #cj #bh ,daily range #be #bd #be #bd #bd #bj #bb ,relative humidity #ge #gd #gc #fi #fb #eh #gj ,days with 4#ja or more rain #j #j #a #c #c #f #dj ,percentage sunshine #gf #gi #gg #gf #gg #gd #ga ,hourly wind velocity #d4g #d4f #d4e #d4e #d4f #e4j #d4i ---------------------------------------- ---------------------- ,miami1 ,florida ---------------------------------------- ---------- ,,data ,,jan4,,feb4,,mar4,,apr4,,may ,,june ---------------------------------------- ---------- ,maximum #fi #gj #gf #hj #hf #hi ,highest maximum #he #hh #ib #ic #id #id ,minimum #eh #ei #fd #ff #gj #gc ,lowest minimum #bi #bi #ci #df #fb #fa ,daily range #aa #aa #ab #ad #af #af ,relative humidity #ha #hj #gi #gf #gi #hb ,days with 4#ja or more rain #aj #h #g #g #aj #ad ,percentage sunshine #fj #fb #fg #gc #fg #fj ,hourly wind velocity #aa #aa #aa #aa #aj #i ---------------------------------------- ---------- ---------------------------------------- ---------------- ,,data ,,july,,aug4,,sept4,,oct4,,nov4,,dec4,,a nnual ---------------------------------------- ----------------- ,maximum #hi #hi #hh #hb #gf #gj #hj ,highest maximum #if #if #id #ic #hh #ia #if ,minimum #ge #ge #gd #ga #fg #fa #fh ,lowest minimum #fi #fg #fb #ec #ch #cb #bi ,daily range #ad #ad #ad #aa #i #i #ab ,relative humidity #hb #hc #hc #hj #gi #ha #hj ,days with 4#ja or more rain #ad #ae #ag #ae #i #i #ace ,percentage sunshine #fd #fd #fb #ec #fa #eg #fb ,hourly wind velocity #h #h #i #ab #aa #aj #aj ---------------------------------------- ----------------- ,u4 ,s4 ,,weather ,,bureau 7,continued7 ,,average ,,temperature1 ,,humidity1 ,,days ,,with ,,rain1 ,,cloudiness1 ,,and ,,wind ,,at ,jacksonville1 ,florida ,,data ,,jan4,,feb4,,mar4,,apr4,,may ,,june ---------------------------------------- ---------- ,maximum #ef #eg #fc #fg #ge #hj ,highest maximum #ha #hf #ia #ib #ajh #aja ,minimum #dg #di #ed #ei #fc #gb ,lowest minimum #ae #aj #bf #cd #df #ed ,daily range #i #h #i #h #ab #h ,relative humidity #ha #gi #gg #gd #ge #gi ,days with 4#ja or more rain #i #i #h #g #i #ac ,percentage sunshine #ee #eg #fh #gc #ga #fe ,hourly wind velocity #h #h #i #i #h #h ---------------------------------------- ---------- ,,data ,,july,,aug4,,sept4,,oct4,,nov4,,dec4,,a nnual ---------------------------------------- ----------------- ,maximum #hb #hb #gh #gj #fb #ef #fi ,highest maximum #ajd #aja #ii #ie #hf #hb #ajd ,minimum #gd #gd #ga #fc #ed #dg #fa ,lowest minimum #ff #fd #di #cg #bf #ad #aj ,daily range #h #h #g #g #h #i #h ,relative humidity #hj #hc #hd #hb #ha #ha #hj ,days with 4#ja or more rain #ae #ae #ac #aj #h #h #abd ,percentage sunshine #fc #fc #ei #ef #fc #ec #fb ,hourly wind velocity #g #g #g #h #g #g #h ---------------------------------------- ----------------- ,san ,diego1 ,california ---------------------------------------- ---------------- ,,data ,,jan4 ,,feb4 ,,mar4 ,,apr4 ,,may ,,june ---------------------------------------- ---------------- ,maximum #fb4b #fb4f #fc4f #fe4b #ff4j #fi4b ,highest maximum #hc #hi #ii #if #ih #id ,minimum #df4d #dg4f #di4f #eb4d #ee4e #eh4g ,lowest minimum #be #cd #cf #ci #de #ej ,daily range #ae4h #ae4j #ac4i #ac4b #aj4e #aj4e ,relative humidity #ga #gd #gd #ge #gg #hj ,days with 4#ja or more rain #g #g #g #d #c #a ,percentage sunshine #fg #fg #ff #fi #eh #fb ,wind velocity #e4a #e4h #f4b #f4d #f4d #f4a ---------------------------------------- ---------------- ---------------------------------------- ----------------------- ,,data ,,july ,,aug4 ,,sept4 ,,oct4 ,,nov4 ,,dec4 ,,annual ---------------------------------------- ----------------------- ,maximum #gb4c #gc4f #gc4a #gj4d #fg4g #fd4c #fg4e ,highest maximum #ic #ic #aaj #if #ic #hd #aaj ,minimum #fb4b #fc4f #fa4c #ef4f #ea4d #dg4i #ed4e ,lowest minimum #ed #ed #ej #dd #cf #cb #be ,daily range #aj4a #aj4b #aa4i #ac4f #af4d #af4c #ac4a ,relative humidity #ha #hj #gi #gf #gj #fh #ge ,days with 4#ja or more rain #j #a #a #c #d #f #dd ,percentage sunshine #fg #gb #gb #gc #gf #gd #fh ,wind velocity #e4i #e4g #e4g #e4c #e4j #e4j #e4g ---------------------------------------- ----------------------- ,u4 ,s4 ,,weather ,,bureau 7,continued7 ,,average ,,temperature1 ,,humidity1 ,,days ,,with ,,rain1 ,,cloudiness1 ,,and ,,wind ,,at ,tampa1 ,florida ,,data ,,jan4,,feb4,,mar4,,apr4 ,,may,,june ---------------------------------------- ---------- ,maximum #fi #gj #gg #hj #hf #hi ,highest maximum #hb #hf #ib #ij #id #ie ,minimum #ea #eb #eh #fa #fg #ga ,lowest minimum #bc #bb #cb #ch #ec #fd ,daily range #ah #ah #ai #ai #ai #ah ,relative humidity #hb #hj #hj #ge #ge #hj ,days with 4#ja or more rain #d #f #f #c #d #i ---------------------------------------- ---------- ,,data ,,july,,aug4,,sept4,,oct4 ,,nov4 ,,dec4 ,,year ---------------------------------------- ------------------ ,maximum #hi #hi #hh #hb #gf #gj #hj ,highest maximum #if #if #if #ic #hg #hc #if ,minimum #gc #gc #gb #fe #eh #eb #fc ,lowest minimum #fe #ff #ed #dc #cb #ai #ai ,daily range #af #af #af #ag #ah #ah #ag ,relative humidity #hb #hc #hd #hj #ha #hb #hj ,days with 4#ja or more rain #aa #ab #g #d #d #e #ge ---------------------------------------- ------------------ ,bermuda ,observations taken on the hill at ,prospect1 #bej feet elevation1 and furnished through the courtesy of ,sir ,frederick ,stupart1 ,director of ,canadian weather service ---------------------------------------- ---------------- ,,data ,,jan4 ,,feb4 ,,mar4 ,,apr4 ,,may ,,june ---------------------------------------- ---------------- ,maximum #fg #fg #fh #gj #gd #gh ,highest maximum #gi #ge #gh #hj #hc #hh ,minimum #eh #eg #eg #eh #fc #fh ,lowest minimum #ci #de #dd #dj #di #ed ,daily range of temperature#aj #aj #aa #aa #aa #aa ,relative humidity #hb #ha #ha #ha #hd #he ,days with 4#ja rain or more#ag #af #ae #ab #aa #aa ,hourly wind velocity #ae #af #ae #ad #ab #aa ,greatest monthly rainfall #i4gaaj4djaj4jeac4ca #i4jiaj4ih ,average rainfall #d4ij #d4gi #e4je #d4ij #d4ci #e4ah ---------------------------------------- ---------------- ---------------------------------------- ---------------------- ,,data ,,july ,,aug4 ,,sept4,,oct4 ,,nov4 ,,dec4 ,,annual ---------------------------------------- ---------------------- ,maximum #hd #he #hc #gh #gc #fi #ge ,highest maximum #ib #id #ia #hh #hb #gi #id ,minimum #gc #gd #gb #fi #fc #fj #fd ,lowest minimum #fe #fd #ei #fj #di #df #ci ,daily range of temperature#aa #aa #aa #aa #aj #aj #aa ,relative humidity #hd #hc #hc #hb #ha #ha #hb ,days with 4#ja rain or more#ab #ae #ad #ae #af #ag #aga ,hourly wind velocity #aa #aj #aa #ab #ac #ad #ac ,greatest monthly rainfall #aa4bdba4ccaf4cjag4gcaa4cfaj4eh ,average rainfall #c4gf #e4ih #e4bd #g4ia #d4cb #d4ih #fa4dj ---------------------------------------- ---------------------- ,the ,scientific ,american thus speaks of the uses of climatic data3 8,what are climatic statistics good for8 ,to this query one is tempted to retort3 ,what are they not good for8 ,let us set down a few typical cases in which such data are desired4 8,a merchant plans to undertake the sale of rubber coats in foreign markets4 ,hence he wishes to know all about the distribution of rainfall1 both geographically and as to season4 ,which are the rainy regions of the globe8 ,when do the heaviest occur in each of these regions8 ,where do the prevailing temperatures indicate the need of heavy coats1 and where light8 8,an invalid contemplates visiting a certain health resort4 ,what mean temperatures occur there at the season of the proposed visit8 ,what ranges of temperature between day and night8 ,how much does the temperature vary from day to day8 ,how much sunshine may be expected8 ,is the atmosphere moist or dry8 ,what of the winds8 ,such are some of the questions he is likely to ask4 8,a horticulturist proposes to introduce a foreign plant in this country4 ,where will he find the most favorable climate for it8 ,in order to settle this question he first tries to secure certain information about the climate of the plant's original habitat--the march of temperature through the season of growth1 average dates of first and last frost1 normal fluctuations of rainfall1 humidity1 sunshine1 etc4 ,if the desired information is obtained1 the next step is to ascertain where 7if anywhere7 similar climatic conditions prevail in the ,united ,states1 and this is generally an easy task4 8,an engineer is planning a sewer system4 ,he needs data of excessive rainfall for the locality under consideration1 so that he may estimate the maximum amount of storm-water the sewers will ever need to dispose of in a given time4 ,their capacity should not exceed this amount beyond a reasonable margin of safety3 otherwise cost of construction would be unnecessarily great4 8,this list of examples might be extended almost indefinitely4 ,it will suffice1 however1 to show how wide a range of climatic information is required to meet all possible demands4 ,the different branches of industry are concerned with different sets of climatic data4 ,one set helps determine the best location for a railroad3 another the kind of goods that will be shipped over it and the way in which they will need to be packed and cared for during shipment4 ,the climatic conditions that must be considered in planning a military campaign are quite unlike those that engage the attention of a hydrological engineer in laying out a system of irrigation4 ,climatic statistics of interest to aviators are not identical with those that bear upon the problems of ecology or forestry or sanitation4 ,in short1 climate means different things to different people40 ,christmas in ,many ,climes4 ,a general idea of the diversification of climate may be gathered from a description of the weather of some particular day of the year as it exists in many different parts of the world4 ,one is too prone to assume that the weather one has on a given day prevails everywhere4 ,for the moment one does not consider the effect of distance from the equator1 proximity to large bodies of water1 and elevation above sea level and above the surrounding region4 ,when a holiday or any day of special interest occurs1 while the weather cannot make the occasion a success1 it can quite effectively destroy all pleasure in the event4 ,when we approach the day of all days in the year when two fifths of the people of the world celebrate the natal day of ,christ1 interest in the weather increases4 ,the little ones of our clime pray that a mantle of snow may cover the ground1 so that dear old ,santa ,claus may come with his reindeer and sleigh4 ,the boys and girls long for the snow-covered hillsides and the glassy ponds2 and even our good old grandmother smiles in anticipation of such a ,christmas ,day as gladdened her heart when she was a wee tot4 ,it may be interesting to know under what kind of skies the people of other lands celebrate this international holiday4 ,in the ,northern ,hemisphere places near the same latitude may have weather conditions greatly at variance the one from the other1 because of conditions previously explained4 ,it is our winter now2 not because the sun is farthest from us1 for in five days the earth will reach the time of perihelion in its course around the sun1 and be nearer to the central luminary than at any other time of the year1 but because the inclination of the earth's axis causes us to receive the rays of the sun at a lower angle than during any other season and its intensity is reduced4 ,the conditions are reversed to the people of the ,southern ,hemisphere2 they now receive the most direct rays of the sun and have their summer1 which is intensified by the nearness of the earth to the sun4 ,the event that gave origin to our ,christmas holiday occurred nearly two thousand years ago in ,bethlehem of ,judea2 and it may be a new idea to us to try to think of the weather that prevailed at that time and the character of the ,christmas ,day that land may have this year4 ,we know that it was not cold and cloudy on that eventful night so long ago1 for the shepherds were feeding their flocks upon the hillsides and the ,wise ,men of the ,east beheld a star and followed it4 ,the star shone brightly from the time they left ,herod until they reached the place where the ,infant lay4 ,we may therefore judge that this part of their journey was made under a clear sky and that the same conditions prevailed at ,bethlehem4 ,weather observations made at ,jerusalem1 a few miles from ,bethlehem1 during modern times1 show that during ,december there are less than fourteen cloudy days on the average4 ,the prevailing winds are from the ,mediterranean ,sea1 only thirty miles to the west of ,bethlehem1 and therefore rarely does the temperature exceed #fe during the day or fall to freezing at night4 ,while there is evidence that the climate is drier now throughout all of the ,holy ,land than at the birth of ,christ1 it is highly probable that when ,he was born the stars were shining brightly and the hills were green and beautiful and the weather smiling its benediction upon the ,son of ,god4 ,we now will glance at the weather that experience teaches us will probably prevail in some of the principal cities of the world on ,christmas ,day1 and thus have impressed upon us the fact that on any day of the year humanity lives under widely differing weather conditions throughout the world4 ,in our own country we know that ,maine is the home of ice1 snow1 and chilling blasts1 while in ,california and ,florida orange blossoms perfume the temperate air4 ,in ,london ,christmas is not always bright and comfortable1 for on the average twenty-one days in ,december are cloudy and the temperature ranges from a few degrees below freezing at night to about #ej during the day4 ,in ,paris the weather is about the same as in ,london4 ,it has the same percentage of cloudiness1 and its daily range of temperature is from #cb to #de1 slightly colder than ,london4 ,the influence of wind direction and the relation of water and land areas to the location of a city are well exemplified in the fact that ,paris1 farther south than ,london1 has a lower winter temperature4 ,in the ,united ,states the coldest winter winds are from the northwest and they also would be so in ,western ,europe were it not for the fact that they draw from the ocean1 whose waters are much warmer in winter than the interior of the continent of ,europe4 ,the northeast winds are therefore the coldest that come to ,paris and ,london4 ,in the first case they draw from the cold interior1 and in the second case the air in passing to ,london from the northeast must pass over the ,north ,sea and the extreme temperature of the cold land is somewhat modified by even this comparatively small body of water with the result that the average daily maximum temperature of ,london for ,december is five degrees warmer than its neighbor some two hundred miles farther south4 ,berlin and ,vienna have the same degree of cloudiness1 but there the similarity ceases4 ,berlin1 only about one hundred miles from the ,baltic ,sea on the northeast and about double this distance from the ,north ,sea on the northwest has an average range of but eight degrees between day and night temperatures1 while ,vienna1 deep-set in the interior of a great continent1 has a daily range of thirty-seven degrees1 the average temperature swinging from #ac to #ej each day during ,december4 ,constantinople was named after the ,roman ,emperor who made it his capital and who first protected the early ,christians from persecution1 then became converted and1 in the manner of his time1 forced others to accept the doctrine at the point of the sword4 ,here ,christianity was first recognized and adopted as a ,state religion1 but since the middle of the fifteenth century ,constantinople has been the home of the ,sultan of ,turkey and the principal city of those who worship ,muhammid as the prophet of ,god instead of ,christ4 ,this ancient city1 so interwoven in the history of ,christianity1 has a delightful climate at ,christmas time1 the daily range being from between a little above freezing and #fe or #gj1 with clouds obscuring the sky about one half the time4 ,historical ,rome has about as many clear days as cloudy ones and the days are pleasant and the nights simply cool4 ,at ,cairo1 in the land where ,joseph was sold into bondage and where ,pharaoh raised him to the highest position in the land next to his own1 no more delightful place can the traveler find at ,christmas time4 ,only one day in three is cloudy and the gentle winds are warm and balmy1 with a daily range in temperature of #ab4 ,in ,calcutta there is a great amount of sunshine1 only one day in five being cloudy1 with an average daily minimum temperature of #eh and a maximum of #hj4 ,bombay is also sunshiny at this time of the year and excessively hot1 with a range each day from #ff to #hh4 ,here1 as at ,calcutta1 ,brahmanism and ,buddhism rule instead of ,christianity4 ,china1 that enormous empire that believes in the ethical philosophy of ,confucius1 whose inhabitants have lived for four thousand years with less strife and bloodshed than any other nation1 has as great a variety of climate during ,december in the widely separated parts of its broad domain as has the ,united ,states4 ,on any day of the ,christmas month some parts of this country are bound in icy chains1 while other parts are sweltering in a torrid temperature4 ,that wonderful ,island--,japan--whose people have made such amazing strides in catching up with the most advanced civilization of the ,occident1 and who never have accepted ,christianity1 has a most delightful climate during winter1 with a large amount of sunshine and moderate temperatures4 ,the vast ,christian nation so long ruled by the ,tzar1 and now in such deplorable chaos1 has a varied climate during ,december4 ,from temperate conditions in the southern portion of its ,european possessions it gradually grows colder as one goes northward until a region of great severity is reached4 ,at ,petrograd the average night temperature is #f below zero4 ,at ,moscow it is colder1 the average of its minimum temperature being #aa below4 ,two thirds of the time it is cloudy at these two cities4 ,verkhoyansk1 in the central portion of ,siberia1 is nearly the coldest place in the world where observations are regularly taken4 ,there ,christmas ,day may be ushered in with a temperature as low as #ge below zero4 ,for days at a time this extreme cold remains1 the warmest part of the day varying but little from the coldest4 ,in many of the cities of the ,southern ,hemisphere ,christmas ,day is likely to be such as will cause the sojourner to long for some cooler region4 ,there it is midsummer1 the grass is green and the fruit is on the tree4 ,we of the ,north could hardly realize that it is ,december4 ,in the pampas of the ,argentine ,republic everything is parched4 ,the white stucco walls and the red tile roofs in the cities reflect the intense rays of the sun into the shimmering air4 ,in ,rio de ,janeiro the days are almost unbearable1 the daily temperature rising to #ajj and over at midday and seldom falling to #fj at night4 ,bear in mind that the greater part of the area of ,south ,america lies between the equator and #cj south latitude4 ,but wherever in these ,south ,american cities one can escape to an elevation of several thousand feet a pleasant temperature may be found4 ,at ,santiago1 ,chili1 it is more comfortable than in ,brazil1 for the nights are cool1 even though the day temperatures rival those of the ,argentine ,republic4 ,but here the cool mountain tops are almost hanging over the coast cities4 ,at ,cape ,town1 in the extreme south part of ,africa1 two days out of three are clear and the daily range of temperature is from #dh to #hc1 making fairly pleasant conditions during the ,christmas holidays4 ,at ,melbourne1 ,australia1 one half of the days are cloudy1 and the temperature is moderate1 having a range from #ed to #ge4 ,thus we see that the climatological features of the world1 not only on ,christmas but on any other day of the year1 are as varied as the hopes and wishes of man1 and whatever his desires or physical necessities may be1 a climate may be found under the influence of which he may find pleasure and gain health4 ,the ,hottest and the ,coldest ,places in the ,world4 ,it is an innate characteristic of the human race to be interested in the abnormal1 whether it be in the achievements of men or in the extremes of natural phenomena4 ,this is especially true with regard to the weather4 ,during periods of extremes of heat or cold the natural inquiry is as to whether there ever has been a period of equal or greater severity4 ,although suffering intensely there always is a desire to 8beat the record40 ,it therefore may be of interest briefly to refer to the hottest and the coldest places in the world4 ,north ,america4 ,one of the most torrid places in the ,united ,states is in that remarkable region known as ,death ,valley4 ,it is located in ,southern ,california4 ,its name is supposed to be derived from a melancholy tragedy that occurred in #ahej1 in which every member of a party of emigrants perished in ,death ,valley from thirst and exhaustion1 leaving the bones of themselves and their animals to whiten in the sun4 ,the valley is the bed of an ancient salt sea which existed when the climate was much wetter than now2 its soil is largely composed of sand1 salt1 and borax4 ,the borax deposits are large2 at places they form crusts that support the weight of travelers4 ,the length of the valley is seventy-five miles1 but it is narrow at the bottom1 in places being no more than six miles4 ,one of its remarkable features is that its bottom1 in many places1 is three hundred feet below the level of the sea1 one hundred miles to the west4 ,it is fed by several small streams and innumerable warm springs1 the water from which is entirely absorbed by the porous soil1 although water may be found by digging down a few feet4 ,the water is unfit for use4 ,it is a desolate and forbidden region1 inhabited by gnats1 toads1 lizards1 and snakes4 ,however1 the employees of a company engaged in the business of marketing borax spend a portion of each year there4 ,in #ahia an observer of the ,u4 ,s4 ,weather ,bureau remained in ,death ,valley from ,may to ,september1 during which time he made daily observations of the weather4 ,his experience was a most trying one1 drawing heavily upon his physical and mental stamina to complete the period of time that had been set for him4 ,for the entire time of one hundred and fifty-four days less than one half an inch of rain fell4 ,there occurred several days in succession with a temperature of #abb4 ,however1 this is not the highest temperature ever recorded in the ,united ,states4 ,in ,july1 #ahhg1 at ,mammoth ,tank1 in the ,colorado ,desert1 the temperature reached #abh in the shade1 and again1 in #ahhd1 #abd was reached at the same place4 ,on ,july #ah1 #ahia1 in ,death ,valley1 the maximum was #abj and the minimum #ii1 making an average for all hours of #ajh4f4 ,the extremely high temperatures reached in the ,colorado ,desert1 which embraces a portion of ,southern ,california and ,arizona1 do not vary greatly from those of ,death ,valley2 they are not exceeded anywhere in ,central or ,north ,america4 ,such degrees of heat1 if experienced for two or three weeks in the more humid regions of the eastern half of the ,united ,states1 would nearly depopulate the region by the havoc of death4 ,the lowest temperatures in the ,united ,states occur in extreme northern portions of ,minnesota1 ,north ,dakota1 and ,montana1 where temperatures from #ej to #ee below zero have been recorded4 ,it is interesting to note that in this same region the summer temperatures have risen to readings of from #aje to #ajh4 ,of course this heat is quite different in its effects upon life from the heat of the ,gulf or ,atlantic coasts4 ,one feels a marked difference between the sun and the shade temperatures in these semi-arid regions4 ,sunstroke is infrequent and death seldom results from exposure1 as it does in the ,east4 ,the region of severest cold in ,north ,america is found about the ,great ,bear ,lake in the ,british ,northwest ,territory1 where temperatures of #eh below zero have been recorded4 ,south ,america4 ,the hottest portion of ,south ,america is in the interior1 with extensive systems of mountain ranges along the coast preventing the inward flow of the moist rain-bearing winds from the ocean4 ,in a stretch of country extending from ,uruguay northward into the interior of ,brazil1 the average of the highest temperature of each year for a period of several years is #ajd1 with individual readings much higher4 ,except on the top of the mountains1 or well up their sides1 no severely cold weather occurs in ,south ,america1 seven eighths of its territory lying between the equator and latitude #cj south4 ,africa4 ,in ,africa is to be found the hottest region of the world1 the great ,desert of ,sahara1 upon whose sands beats down the fierce tropical sun with merciless intensity4 ,here shade temperatures of #acj are frequently experienced4 ,only those bred to extreme tropical desert heat can long live under such conditions4 ,in a portion of the desert lying between ,egypt and the ,red ,sea the temperature has been known not to fall below #aac for a period of ten days1 while on several nights the lowest temperature reached was #aah1 with a practically calm air4 ,africa lies with about one half of its immense area on each side of the equator1 and the greater part of its territory inside the ,tropical ,zone4 ,except in a few isolated cases on high mountains1 temperatures as low as zero never are experienced4 ,europe4 ,the warmest portion of ,europe is in the region round and about the ,mediterranean ,sea4 ,the coldest places in all ,europe are in the western part of ,russia and in the northern part of the ,scandinavian ,peninsula4 ,here the average of the coldest days of winter is #ej below zero4 ,asia4 ,it is difficult to determine in what part of ,asia the highest temperature occurs1 as data from many parts are meager4 ,it is known however that extremely hot weather prevails in ,india and ,arabia4 ,siberia1 however1 experiences the coldest weather to be found anywhere in the world4 ,at ,werchojansk1 in that country1 a temperature of #ij4d below zero was observed in ,january1 #ahhd1 while the average temperature for the whole month was #fi4d below zero4 ,the coldest weather of the world is not found at the ,north or the ,south ,pole1 as many suppose1 but rather at the center of vast continents1 far from the modifying influence of oceans4 ,australia4 ,in extreme heat the interior of ,australia is fairly comparable with northern ,africa1 ,persia1 ,afghanistan1 and northern ,india1 where every year maximum temperatures of #aae occur1 and where1 at times1 an extreme heat of #abj or #abe is experienced in the shade4 ,we now know that the forceful1 dominating peoples come out of the regions where the heat is not so great as to debilitate1 nor the cold so fierce as to deaden the mental and the physical faculties2 but rather from the region of the thoroughfare of the great circum-polar storm tracks1 where there are frequent changes of weather from sunshine to clouds1 and where there is a fairly wide difference in temperature between night and day and between winter and summer4 ,for the best cordination of the mental and the physical faculties1 so as to produce the most efficient composite of man1 the temperature should range between #de and #ej at night and between #fe and #gj during the day1 with about sixty-five to seventy per cent4 of relative humidity4 ,some day we will artificially create the exact conditions of temperature and moisture needed for patients in hospitals and sanitaria4 ,science is persistently seeking means to increase comfort and prolong life4 ,,chapter ,,xv ,,condensation ,,how ,,haze1 ,,rain1 ,,snow1 ,,hail1 ,,frost1 ,,cloud1 ,,and ,,fog ,,are ,,formed ,haze is what might be called diluted cloud or fog2 it differs from them only in the degree of its density4 ,one may see several miles through a haze1 because the minute particles of spheres of water or ice are far apart in comparison to what they are in fog or cloud4 ,raindrops vary in size from ,o4#jc to ,o4#bj of an inch in diameter4 ,each drop is composed of literally millions of minute specks of water that have condensed each about a minute mote of dust4 ,these motes are a million of times below anything that may be seen with the most powerful microscope4 ,recall what is said in ,chapter ,,iv about the size of the molecules in water3 if a raindrop were enlarged to the size of the earth1 the molecules of which it is composed would be no larger than a baseball1 and the smallest of them no larger than tiny green peas4 ,without free surfaces upon which condensation may begin there can be no rainfall4 ,dust motes furnish these surfaces2 without them air may be supersaturated without condensation occurring except where it comes in contact with solid matter4 ,the little spherical masses of water join together so as to form raindrops in some manner not well understood4 ,when enough of them coalesce so that the weight of the drop is too heavy to be supported by the motions of the air it falls to the ground1 or is evaporated by the warmer and drier lower air4 ,raindrops form mainly in the stratum between one and three miles above the earth4 ,it is seldom that the stratum of air next the earth is saturated1 even during rainfall4 ,one might evaporate millions of gallons of water and find no dust as a residue1 or at least nothing visible to the human eye1 so infinitesimal are the motes of condensation4 ,as high as thirty millions have been shown to exist in a single cubic centimeter of air 7,chapter ,,iv71 and a million times that number could occupy such space without being visible1 and the dust mote is composed of molecules1 and the molecules of atoms4 ,it is impossible for the human mind to grasp the idea of the degree of smallness to which the atom attains1 and when one tries to conceive of the electrons from which the atom is built up1 he must try to think of them not as objects but as the place or condition where matter slowly fades away into nothing2 as the place possibly where matter is transmuted into electrical energy and ceases to exist4 ,the raindrop cannot be formed at great altitudes because the vaporous atmosphere is confined to low levels by temperature4 ,at #ajj1 which often exists at the bottom of the atmosphere1 air at saturation contains #ai4gg grains the cubic foot2 at #hj1 #aj4ic2 at zero1 4#jd2 and at -#dj1 which always may be found at about four and one half miles high1 air cannot contain in excess of 4#ja of a grain4 ,raindrops are mainly caused by the cooling of air down to its dew point4 ,rain ,water ,is ,not ,pure4 ,hailstones often incase foreign matter that has been carried upward by violent winds4 ,rain water is pure when it is condensed1 but it gathers other matter as it falls1 such as the pollen of plants1 and the broken siliceous shells of microscopic life carried by winds of the tropics2 it also washes ammonia from the air in small quantities1--about thirty pounds per acre in the eastern half of the ,united ,states each year4 ,a raindrop increases in velocity as it falls until the resistance of the air becomes just equal to the weight of the drop2 after that it falls at a uniform rate4 ,it will surprise many to learn that if it were not for the retardation effected by the resistance of the air1 a raindrop falling from only half a mile would be as dangerous to life as a rifle bullet1 for the speed with which a projectile travels can be made sufficient to compensate for its softness or yielding qualities4 ,how ,much ,water ,is ,it ,possible to ,precipitate from the ,earth's ,atmosphere8 ,if the entire amount of water vapor present in the atmosphere were precipitated instantly it would furnish a rainfall of only two inches for the whole surface of the earth4 ,a steady downpour for twenty-four hours usually amounts to some two or three inches4 ,over small areas and in exceptional cases as many feet have been known to fall in that time1 as fresh1 vapor-bearing winds steadily blew into a storm center1 rose1 discharged their burdens as they cooled with ascent1 and then flowed away1 again to be charged with moisture when they came into contact with wet surfaces4 ,it is impossible to drown the entire earth with rainfall1 no matter how long continued4 ,illustration3 ,,fig4 #ca4--,,snow ,,crystals4 ,snow4 ,snow is water vapor condensed in the congealed form1 without passing through the liquid state4 ,when the minute pieces of ice of which the flake is composed are magnified several hundred times they are found to be composed of the most wonderfully beautiful figures4 ,thousands have been photographed1 but the versatility of nature is so great that no two ever have been found that were exactly alike4 ,figure #ca gives some idea of their infinite variety and perfect symmetry4 ,they are always governed by the number six4 ,the most common form at the beginning of winter is a six-rayed star1 each ray branching4 ,as the winter advances and the cold becomes more severe1 the flakes take a simpler form1 finally becoming slender six-sided prisms with sharp ends1 under the influence of severe cold waves4 ,great pain is inflicted on the exposed parts of the body when these prisms are encountered in a high wind4 ,when condensation takes place in a warm stratum it will be in the form of minute massive spherical particles or spherules4 ,if these spherules are then whirled aloft by ascending currents it is possible for them to be cooled to far below the freezing point without turning to ice2 they will1 however1 congeal instantly when they touch one another or are jostled by touching any solid or liquid surface4 ,they may give a coating of ice to the limbs of trees and the coating may increase until the limbs break1 and the surface of the earth thus may be covered with thin ice called sleet4 ,hail4 ,there is a difference of opinion among meteorologists as whether the thunderstorm whirls about a vertical axis1 like the tornado and the hurricane1 or whether it rotates about a horizontal axis4 ,one may well account for the formation of the hailstone by assuming that its alternating layers of snow and ice are caused by the horizontal roll of a thunderstorm1 the under part of which has a temperature at or above freezing and the upper half much below freezing4 ,a raindrop is formed in the lower part1 frozen in its course through the upper part1 receives a fresh coating of water or snow with each revolution and a freezing before its circuit is completed4 ,it thus gains in size until it becomes too heavy to be sustained by the whirling storm-cloud1 when it falls to earth4 ,hail usually has the size of small peas1 but occasionally it falls in chunks sufficiently large to kill cattle in the fields4 ,on ,august #ae1 #ahhc1 a hailstone weighing eighty pounds is said to have fallen in ,kansas4 ,frost4 ,frost is composed of beautiful crystallizations1 similar to snow4 ,chapter ,,vii describes the process of formation in detail4 ,cloud4 ,cloud is formed by the cooling by expansion as currents of air are carried aloft4 ,clouds are composed of minute watery droplets or of ice spicul1 depending on their temperature1 and the latter largely is determined by elevation4 ,a cloud differs from mist or rain in the size and number of its particles1 and from fog in its position and the method of its formation4 ,there are three fundamental formations1 the cirrus1 cumulus1 and stratus4 ,the others are combinations of these4 ,the cirrus are thin1 high1 veil-like clouds1 always composed of ice spicul2 the cumulus look like great banks of snow with bulging1 oval tops in which thunder heads may form2 the stratus spread out like a great blanket4 ,the cirrus usually fly at the top of the storm stratum1 some five to seven miles high2 the other clouds at some lower level4 ,when rain is falling from a cloud1 it is called nimbus4 ,fog ,is ,cloud at a ,low ,level4 ,it is formed by warm water vapor rising from lakes or rivers into the cool night air at the bottom of valleys1 or by the cold waters of oceans being forced up over a bar1 where the coldness that they impart to the adjacent air condenses some of its vapor4 ,artificial ,rain ,making4 ,many swindlers have preyed upon the credulity of the public by claiming to have a process for the making of rain1 and in some cases large sums of money have been paid by commercial or other associations to these charlatans4 ,in #ahib the ,united ,states ,congress appropriated #bj1jjj for the testing of the theory that rain could be created by the setting off of large quantities of explosives4 ,the experiment was unsuccessful1 as the scientists of the ,government insisted it would be4 ,the ,greeks had a popular belief that when a host of their soldiers went out to meet an army of ,persians the vapor rising from the hot breath1 blood1 and sweat of the struggling mass was later condensed into rain by the concussion of the battle clubs and the hoarse cries of the victors1 and many of the veterans of our ,civil ,war were firm in the opinion that their great battles were followed by rains that were the result of the cannonading4 ,both the ,greeks and our ,american soldiers were mistaken4 ,rain often has fallen at the close of great battles1 not because of the concussion of the conflict1 but because rain falls on an average of one day in three in the regions where most of the great battles have been fought1 and the movement of armies began on the fair days when travel was good4 ,if it were the custom to begin battles on rainy days we would have the contrary and equally erroneous theory that concussion clears the atmosphere4 ,prevention of ,hail by the ,firing of ,guns4 ,even a ,papal decree was not entirely effective in preventing the people in southern ,europe from ringing the church bells to prevent the formation of hail when a storm threatened1 and within the past quarter-century large grants of public money were foolishly wasted in the firing by the vineyardists of ,france and other parts of ,europe of a gun specially designed to destroy hail clouds4 ,these guns sent harmless smoke rings a few feet aloft4 ,the writer felt constrained to employ the extensive machinery of the ,weather ,bureau to counteract the effect of glowing accounts of the success of these guns that were sent to this country by some of the ignorant persons employed by this ,government to represent us as consuls abroad4 ,even though the hail-destroying guns occasionally were choked with hail it was difficult for scientists to prevail upon the public to stop their foolish and wasteful practice4 ,,chapter ,,xvi ,,development ,,of ,,the ,,american ,,weather ,,service ,,the ,,largest ,,and ,,the ,,most ,,effective ,,meteorological ,,bureau ,,in ,,the ,,world ,even to those who are familiar with the application of meteorological science to the making of weather forecasts1 and with the material benefits accruing to the commerce and industry of the ,united ,states from timely warnings of marine storms1 frosts1 and cold waves1 it will be interesting to note that at the time of the founding of the first of the thirteen original ,colonies1 at ,jamestown1 ,virginia1 in #afjg1 practically nothing was known of the properties of the air or of methods for measuring its forces4 ,to-day electrically recording automatic meteorological instruments measure and transcribe for each moment of time at two hundred stations in the ,united ,states1 the temperature1 the air pressure1 the velocity of the wind1 the direction of the wind1 the beginning and ending of rainfall1 with the amount of precipitation2 and the presence of sunshine or cloud2 and three thousand voluntary observers each day record the temperature and the rainfall4 ,that we live in an age of great intellectual acumen1 and that he is indeed a wise prophet who can even dimly outline the possibilities of the next century1 is fitly shown by the development of meteorological science during the recollection of the present generation2 although one must admit that in the making of weather forecasts1 valuable as they are1 we have not advanced beyond the partly empirical stage4 ,it is1 therefore1 improbable that in the making of these forecasts we shall ever attain the accuracy acquired by theoretical astronomy in predicting the date of an eclipse or the culmination of any celestial event4 ,it was not until #afdd1 twenty-four years after the landing of the ,pilgrims at ,plymouth ,rock1 that ,torricelli discovered the principle of the barometer and rendered it possible to measure the weight of the superincumbent air at any spot where the wonderful yet simple little instrument might be placed4 ,torricelli's great teacher--,galileo--died without knowing why nature1 under certain conditions1 abhors a vacuum1 but he had already discovered the principle of the thermometer4 ,the data from the readings of these two instruments form the base of all meteorological science4 ,their inventors as little appreciated the value of their discoveries as they dreamed of the coming great western empire which should first use their instruments to measure the inception and development of storms1 and later1 with the aid of the electro-magnetic telegraph1 to give warnings to threatened regions of the approach of hurricanes1 cold waves1 floods1 and frosts that have been worth at least one hundred million dollars to this country during the past ten years without counting the many thousands of lives saved among mariners4 ,doctor ,john ,lining1 of ,charleston1 ,south ,carolina1 kept a daily record of the temperature in this country as early as #agch1 although the accurate thermometers of ,fahrenheit had then been in use but a few years and the errors due to imperfect mechanical construction may have been considerable as compared with the refined instruments now used for measuring temperature4 ,about one hundred years after the invention of the barometer1 viz41 in #agdg1 ,benjamin ,franklin1 the patriot and statesman1 the diplomat1 the scientist1 divined that certain storms may move in a direction opposite to the blowing of the wind and that they progress in an easterly direction4 ,it was prophetic that this idea should come to him long before any one had ever seen charts showing observations simultaneously taken at many stations4 ,but although his ideas in this respect were more momentous than his act of drawing the lightning from the clouds and identifying it with the electricity of the laboratory1 yet his contemporaries thought little of his philosophy of storms1 and it was soon forgotten4 ,it will be interesting to learn how he reached his conclusion as to the cyclonic or eddy-like nature of storms4 ,he had arranged with a co-worker at ,boston to take observations of an eclipse at the same time that ,franklin was taking readings at ,philadelphia4 ,early on the evening of the eclipse an unusually severe northeast wind and rainstorm set in at ,philadelphia and ,franklin was unable to secure any observations4 ,he reasoned that as the wind blew fiercely from the northeast the storm1 of course1 was coming from that direction1 and ,boston must have experienced its ravages before ,philadelphia was reached4 ,reports indicated that the storm was widespread4 ,what was the surprise of ,franklin1 when1 after the slow passage of the mail by coach1 he heard from his friend in ,boston that the night of the eclipse had been clear and favorable for observations1 but that a terrific northeast wind and rainstorm began early the following morning4 ,franklin then sent out inquiries to surrounding stage stations and found that at all places southwest of ,philadelphia the storm began earlier and that the greater the distance the earlier the beginning as compared with its advent in ,philadelphia2 but northeast of ,philadelphia the time of the beginning of the storm was later than at the latter city1 the storm not reaching ,boston until twelve hours after it began at ,philadelphia4 ,in considering these facts a line of inductive reasoning brought him to the conclusion that the wind always blows towards the center of the storm2 that the northeast storm which ,boston and ,philadelphia had experienced was caused by the suction exercised by an advancing storm eddy from the west which drew the air rapidly from ,boston toward ,philadelphia1 while the source of the attraction--the center of the storm eddy--was yet a thousand miles to the southwest of the latter place2 that the velocity of the northeast wind increased as the center of the storm eddy advanced nearer and nearer from the southwest until the wind reached the conditions of a hurricane2 that the wind between ,boston and ,philadelphia shifted its direction so as to come from the southwest after the center of the storm eddy had passed over this region2 and that the force of the wind gradually decreased as the center of attraction--which always is the storm center--passed farther and farther away to the northeast4 ,another man whose name is dear to the heart of every patriotic ,american conducted1 in conjunction with a friend1 a series of weather observations1 beginning in #agga and continued during the stirring times of the ,revolution4 ,this was the sage of ,monticello1 ,thomas ,jefferson4 ,during the first half of the nineteenth century1 nearly a hundred years after ,franklin's northeast rainstorm1 ,redfield1 ,espy1 ,loomis1 ,henry1 and other ,american scientists laboriously gathered by mail the data of storms after their passage and demonstrated their principal motions to be such as ,franklin had supposed4 ,professor ,joseph ,henry1 ,secretary of the ,smithsonian ,institution1 in #ahee1 constructed the first daily weather map from simultaneous observations collected by telegraph4 ,he did not publish his forecast but used his large wall map for the purpose of demonstrating the feasibility of organizing a ,government weather service4 ,if there were no other achievements to the credit of the institution founded in this country through the benevolence of the ,english philanthropist1 ,james ,smithson1 who1 by the way1 never gazed upon our fair land1 the work of the ,smithsonian ,institution in connection with practical meteorology would always give it a warm place in the hearts of those who believe the crowning achievements of science consist in giving to the world knowledge which results in the saving of human life1 the amelioration of the sufferings of human beings1 and the acceleration of the wheels of commerce and industry4 ,although ,american scientists were the pioneers in discovering the progressive character of storms and in demonstrating the practicability of weather services1 the ,united ,states was the fourth ,government to give legal autonomy to a weather service4 ,holland established a weather service1 with telegraph reports and forecasts1 in #ahfj2 ,england followed with a smaller service in #ahfa2 and ,france in #ahfc4 ,but none of these countries has an area from which observations can be collected great enough to give such a synoptic picture of storms as is necessary in the making of forecasts of much utility4 ,it would require an international service1 embracing all the countries of ,europe1 to equal1 in extent of the area covered and of the accuracy of its forecasts1 the service of the ,united ,states1 which was begun in #ahgj1 as the result of agitation by ,lapham1 ,henry1 ,abbe1 ,maury1 and others4 ,the vast region now brought under the dominion of twice daily synchronous observations embraces an area extending two thousand miles north and south1 three thousand miles east and west1 and so fortunately located in the interest of the meteorologist as to include an important arc on the circum-polar thoroughfare of storms of the northern hemisphere4 ,simultaneous observations1 collected twice daily by telegraph from two hundred stations1 distributed throughout this great area1 renders it possible at several central offices1 where all the reports are received1 to present to the trained eye of the forecaster a wonderful panoramic picture of atmospheric conditions4 ,each twelve hours the kaleidoscope changes and a new graphic picture of actual changes is shown4 ,the movements of storm centers and cold-wave areas are noted and estimates made as to their probable course during the next twenty-four hours4 ,where else can the meteorologist find such an opportunity to study storms and atmospheric changes8 ,in #ahgj1 and for ten years thereafter1 our forecasts and storm warnings were looked upon by the press and the people more as experiments than as serious statements4 ,the newspapers especially were prone to facetiously comment on the forecasts1 and many were clamorous for the abolition of the service during the first years of its existence4 ,there was some ground for the criticisms4 ,we knew nearly as much about the mechanics of storms at that time as we do to-day1 but we had not1 by a daily watching of the inception1 the development1 and the progression of storms1 trained a corps of expert forecasters1 such as now form a part of the staff of the ,chief of the ,weather ,bureau1 and from which the writer was graduated before he became ,chief4 ,along about #ahhj1 mariners began to note that danger signals were1 in far more than a majority of cases1 followed by heavy winds2 they began to reason that it would be better to take precaution against storms that never came1 than to be unprepared for those which did come according to the forecasts4 ,it is a fact that many times1 by the operation of forces not indicated by the surface readings1 the barometer at the center of a storm begins to rise and the velocity of the whirling mass to decrease4 ,in such a case the storm signals placed in advance of the storm center would fail to give the proper information4 ,again1 the storm center may suddenly acquire a force not anticipated1 or it may pursue a track considerably divergent from the normal for the location and season4 ,in this case1 also1 the forecasts may warn some cities that fail to receive the effects of the storm4 ,however1 during the past few years the staff of the ,weather ,bureau1 which includes the ablest meteorologists in the ,united ,states1 has made a study of the peculiarities of the different types of storms occurring in the different localities during the various seasons of the year1 their line of travel and the force they may be expected to attain4 ,competitive examinations have been held to test the comparative merits of those who1 by natural ability1 are best fitted to correctly and quickly correlate in their minds the conditions shown on a meteorological chart1 and to make accurate deductions therefrom as to the development1 movement1 and force of storms4 ,this line of work and investigation has resulted in improved forecasts2 so much so that mariners now universally heed the storm warnings2 horticulturists and truck gardeners make ample provision for protection against frost2 the shippers of perishable produce give full credence to the cold wave predictions4 ,of the many ,west ,indian hurricanes which have swept our ,atlantic seaboard from ,florida to ,maine during the past many years1 not one has reached a single seaport without danger warnings being sent well in advance of the storm2 and few unnecessary warnings have been issued4 ,the result is that few disasters of consequence have occurred4 ,large owners of marine property estimate that one of these severe storms traversing our ,atlantic coast in the absence of danger signals would leave not less than three million dollars' worth of wreckage4 ,twice a census was taken just after the passage of severe hurricanes to determine the value of property held in port by the danger warning sent out in advance of the storms4 ,in one case the figure was placed at thirty-four million dollars and in the other thirty-eight million dollars4 ,of course this does not represent the value of property saved4 ,it simply shows the value of property placed in positions of safety as a result of the danger signals and warning messages sent to masters4 ,on ,january #a1 #ahih1 an extensive cold wave swept from the ,rocky ,mountains eastward to the seaboard4 ,estimates secured from shippers in a hundred principal cities indicate that property valued at three million four hundred thousand dollars was saved as a direct result of the predictions sent out well in advance of the coming of the severe cold4 ,the utility of these forecasts to the agriculture1 the commerce1 and the industry of the country is so great that there is hardly a daily paper that does not publish weather forecasts in a prominent place1 and there is scarcely a reader who fails to note the predictions4 ,twenty-five years ago mariners on our ,great ,lakes and seaboard depended on their own weather lore to warn them of coming storms4 ,then1 although the number of craft plying our waters was much less than now1 every severe storm that swept the ,lakes or ,atlantic coast left destruction and death in its wake1 and for days afterward the dead were cast up by the receding waves1 and the shores were lined with wreckage4 ,happily this is not now the case1 for the ,weather ,bureau is ever watching the changes of atmospheric conditions1 and giving to the mariner warning of coming storms4 ,each observer telegraphs instantly to the ,central ,office whenever the delicately adjusted instruments at his station show unusual agitation4 ,by this means the inception of many storms is detected when the regular morning and evening reports fail to give notice of their origin4 ,some idea of the vast interests floating on the ,atlantic coast may be had when it is stated that #efbh trans-,atlantic steamers1 with an aggregate of #aj1jgf1adh tons1 and #ehdb sailing craft1 aggregating #b1aje1fhh tons1 entered and left ports on the ,atlantic seaboard during a single year ten years ago1 and the record is vastly greater now4 ,the value of their cargoes is more than a billion and a half of dollars4 ,our coastwise traffic is enormous4 ,fifteen years ago more than seventeen thousand sailing vessels and four thousand steamers entered and left the ports between ,maine and ,florida4 ,the number has largely increased since4 ,from these facts one can roughly measure the value of the marine property which the ,weather ,bureau aims to protect by giving warning of approaching storms4 ,it is the expectation of the meteorologist that some day he will be able to accurately forecast the weather for weeks and months in advance4 ,what a wonderful conservation of human energy would result if it were possible to tell the farmer when the great corn and wheat belts would have abundant rain during the next growing season1 or when droughts would parch and wither the vegetation2 or to truthfully inform the planter of the ,south that the coming season would be favorable or unfavorable for the production of cotton6 ,effort could be withheld in one part of the country1 and greater energy exerted in another4 ,this extension of forecasting doubtless will be accomplished as the result of further study of solar impulses which disturb the orderly processes of the earth's atmosphere and initiate storms1 combined with a comparative study of meteorological data4 ,we may be laying the foundation of a great edifice which shall adorn the civilization of future centuries4 ,as storms of more or less intensity pass over large portions of our country every few days during the greater part of the year1 and as it is seldom that the weather report does not show one or more storms as operating somewhere within our broad domain1 it is easy for some charlatan to forecast thunderstorms about a certain time in ,july1 or a cold wave and snow about a certain period in ,january1 and stand a fair chance to accidentally become famous as a prophet4 ,one may select any three equidistant dates in ,january and forecast high wind1 snow1 and cold for ,new ,york ,city1 and stand a fair chance of having the fraudulent forecast verified in two out of the three cases1 provided that you claim a storm coming the day before or the day after one of your dates is the storm that you expected4 ,from the introduction of the electro-magnetic telegraph in #ahdd down to #ahfi intermittent advocations were made by many in this country for a national weather service4 ,finally ,doctor ,increase ,a4 ,lapham1 of ,milwaukee1 scientist and philanthropist1 so aroused the property and financial interests of the country with the facts that he presented relative to the destruction of life and property by storms on ,lake ,michigan that ,congress1 under provisions of a bill introduced by ,general ,halbert ,e4 ,paine1 was induced to appropriate money to initiate a service4 ,to ,general ,albert ,j4 ,meyer1 ,chief ,signal ,officer1 ,u4 ,s4 ,a41 was intrusted the duty of inaugurating a tentative weather service by deploying over the country as observers the military signalmen of his command4 ,from this beginning has evolved the present extensive ,weather ,bureau1 which is the largest in the world and more intimately serves the needs of the public than any other4 ,in #ahfi ,professor ,cleveland ,abbe published a weather bulletin at ,cincinnati1 based upon simultaneous observations secured by telegraph from about thirty stations4 ,he was the first scientific assistant to ,general ,meyer and remained continuously with the service until his death in #aiai4 ,colonel 7afterward ,brigadier-,general7 ,h4 ,h4 ,c4 ,dunwoody1 ,u4 ,s4 ,a41 served twenty-seven years as an expert forecaster or as the assistant chief of the ,weather ,bureau4 ,general ,a4 ,w4 ,greely1 of ,arctic fame1 the last of the military chiefs1 succeeded ,brigadier-,general ,william ,b4 ,hazen on the death of the latter4 ,professor ,mark ,w4 ,harrington was the first chief of the new civil ,weather ,bureau2 he served but four years and was succeeded by ,professor ,willis ,l4 ,moore1 who remained chief for eighteen years1 serving two years under ,president ,cleveland1 who appointed him1 and during the entire administrations of ,mc,kinley1 ,roosevelt1 and ,taft1 and was removed by ,woodrow ,wilson immediately on taking office4 ,professor ,moore claims the honor of having been the first presidential appointee to incur the displeasure and receive the public condemnation of ,woodrow ,wilson4 ,the present chief is ,professor ,charles ,f4 ,marvin1 who for many years served as an assistant to ,professor ,moore4 ,,index ,,index ,abbe1 ,cleveland1 #bih2 publishes weather bulletin1 #cje2 his long service in the ,weather ,bureau1 #cje ,absolute humidity1 #ci ,absolute zero1 #fb ,arial ocean1 the air a great1 #g ,aroplane1 importance of developing the1 #bg ,africa1 and monsoon winds1 #ajg2 hottest and coldest places in1 #bgi ,agricultural interests1 benefit of ,weather ,bureau service to1 #cja1 #cjb ,air1 great ocean of1 around the earth1 #g2 condition of1 at various levels1 #g-ag2 liquid1 #i2 blue tint of1 #aj2 thinness of stratum of1 that sustains life1 #ad2 elasticity and density of1 #ad2 pressure of1 #ae2 weight of1 #ae2 everything evolved from1 #ae-ag2 effect of cold wave on the1 #cf1 #cg2 explorations of the1 #ah-bh2 circulation of the1 #ee2 increasing pressure increases temperature of1 #fa2 difference between weight and pressure of1 #gg2 course of a current of1 #ii2 earth warmer than1 next above1 #ahj2 cools with ascent and heats with descent1 #ahd2 height of freezing cold in free1 #ahe2 daily range of temperature in free1 #ahe1 #ahf2 movement of1 in valleys1 #bjd2 mountains and movement of1 #bje2 proper temperature and humidity of1 in habitations1 #bag2 water vapor in1 at various temperatures1 #bhd2 retards falling raindrops1 #bhe2 and the formation of cloud1 #bhg1 #bhh ,air travel1 ,major ,blair on1 #bg2 ,lieut4 ,col4 ,henry on1 #bh ,aitken1 ,robert ,grant1 method of counting dust motes1 #dd1 #de ,altitude1 gauged by boiling point of water1 #fj1 #fa2 wind's velocity increases with1 #aji-aaa2 man's adjustment to life at high1 #ahf1 #ahg2 temperature at high1 #baj-bab2 amelioration of disease by moderate1 #bdh1 #bdi1 #bej ,altitudes1 the cold and stillness in the higher1 #aj1 #aa ,american ,weather ,service1 development of1 #bia-cjf4 ,see also ,,united ,,states ,,weather ,,bureau ,ammonia1 #cc ,aneroid barometer1 volunteer observers and the1 #ff2 forecasting weather with the1 #gd-gi ,animal life1 necessity of oxygen to1 #ce ,anti-cyclone1 general cause of1 #ih2 general whirl of1 #ajc2 gyration of1 #ajh1 #aji2 an area of high pressure1 #aai ,appalachian ,mountains1 effects of higher elevation of1 #bca1 #bcb ,argentine ,republic1 ,christmas ,day in1 #bgd ,argon1 #cc ,arrows1 on weather map fly with wind1 #aaf1 #aah ,artificial rain making1 experiments with1 #bhh1 #bhi ,asia1 and monsoon winds1 #ajf2 hottest and coldest places in1 #bgi-bhj ,astoria1 ,wash41 climate of1 #baj ,atlantic ,ocean1 temperatures of waters of1 #agg ,atmosphere1 of the sun1 #b2 of ,jupiter1 ,neptune1 ,uranus1 and ,saturn1 #c2 carbon dioxide in1 #e2 thickness of earth's1 #f2 how it is warmed1 #h2 absorption of heat rays by1 #h2 water vapor in earth's1 #h2 temperature of isothermal stratum of1 #aa2 gases of1 in mechanical not chemical union1 #cb2 importance of proper proportions of gases of the1 #cb2 table of component parts of1 #cc2 beneficial effects of cold wave on1 #cf1 #cg2 dust motes and illumination of the1 #de2 data meager as to circulation of upper1 #ajc1 #ajd2 storms and cold waves great eddies in the1 #aah2 variations in temperature due to motion of1 #afc1 #afd2 absorption of solar rays by the1 #aff-afh ,atmospheres1 how they are formed1 #a2 how maintained and how lost1 #e2 earth's four1 #bi-dg ,atmospheric air1 composition of1 #bi-cg ,atoms1 early belief in formation of all matter of1 #cj2 present knowledge of1 #cj1 #ca2 composition of1 #ca2 of various elements1 #ca1 #cb ,australia1 and monsoon winds1 #ajg2 hottest and coldest places in1 #bhj ,bacteria1 and putrefaction diminish with elevation and over seas1 #aj2 absence of1 at high altitudes1 #dc2 gathered by snow1 ice1 and water1 #dc2 destroyed by sunshine1 #bdh ,balloon1 use of1 in meteorological research1 #ai2 record of temperatures at high altitudes by1 #abd1 #baj-bab ,barometer1 discovered by ,torricelli1 #bc2 aneroid1 #ff2 forecasting weather with the aneroid1 #gd-gi2 table for forecasting weather by1 #gf2 discovery of principle of1 #gg-gi2 effect of storms on1 #gi2 low at ,poles1 #ajc2 data from1 in meteorological science1 #bib1 #bic ,bathing1 fresh and salt water1 #bdi ,berlin1 ,germany1 temperature of earth at great depth at1 #agi2 ,christmas ,day in1 #bga ,bermuda1 sub-permanent ,highs and ,lows in region of1 #aei1 #bea2 climate of1 compared with ,florida and ,california1 #bef-bfa2 author's visit to1 #beg2 range of thermometer in ,hamilton1 #beg2 wind velocity and humidity in1 #beg1 #beh2 charm of1 #beh2 location of1 #beh2 influence of ocean on climate of1 #beh1 #bei2 character of islands of1 #bei1 #bfj2 flowers in1 #bfj2 wind and rainfall in1 #bfa2 meteorological statistics for1 #bfd ,bethlehem of ,judea1 ,christmas ,day in1 #bfh1 #bfi ,bismuth1 nucleus of atom of1 #cb ,blair1 ,major ,william ,r41 on air travel1 #bg ,boiling point of water1 #eg1 #eh2 as a gauge for altitude1 #fj1 #fa ,bombay1 ,india1 ,christmas ,day in1 #bgb ,boston1 ,mass41 influence of ocean on summer temperature of1 #aid ,bowie1 ,e4 ,h41 ,national ,forecaster1 rules for forecasting1 #aea-aec ,brazil1 high temperature in interior of1 #bgh ,cairo1 ,egypt1 ,christmas ,day in1 #bgb ,calcutta1 ,india1 ,christmas ,day in1 #bgb ,california1 summer temperature of coast of1 #aid2 wet and dry seasonal records in big trees of1 #bcf1 #bcg2 climate of ,bermuda compared with that of1 #bef-bfa ,calms1 belt of1 at equator1 #ii ,calorie4 ,see ,,gram-,,calorie ,cape ,town1 ,south ,africa1 ,christmas ,day in1 #bgd ,carbon1 nucleus of atom of1 #ca ,carbon dioxide1 in atmosphere of earth1 #e2 one of earth's atmospheres1 #bi2 functions of1 #ce-cg2 seasonal proportions of1 in air1 #ce2 proportions of1 according to locality1 #ce2 injurious proportion of1 #ce1 #cf2 reaches maximum at night over land1 #cf2 dissolved in sea water1 #cf2 maximum at midday over oceans1 #cf2 density of1 #cf ,carbonic acid gas4 ,see ,,carbon ,,dioxide ,carnegie ,foundation1 investigation of big trees in ,california1 #bcf1 #bcg ,caspian ,sea1 waters of1 have receded1 #bce2 again advancing1 #bce1 #bcf ,centers of ,action1 #aja2 permanent ,highs and ,lows in ,pacific ,ocean are great1 #aeh2 influence of certain1 on climate1 #aib-aid ,centigrade scale1 compared with ,fahrenheit1 #fg1 #fh ,central ,america1 changes of climate in1 #bch ,change of climate1 mistaken ideas of1 #bbe-bcj2 importance of1 to sub-arid ,west1 #bbi2 in period of authentic history1 #bcc1 #bcd2 in ,united ,states1 #bce2 simultaneous in ,europe and ,america1 #bcg2 east and west1 opposite in character from north and south1 #bcg1 #bch2 in ,central ,america1 #bch2 in middle latitudes1 #bci2 in prehistoric times1 #bci2 as recorded by geology1 #bci2 shown by fossil remains1 #bci2 and civilization1 #bdj2 author's views on1 #bdb1 #bdc ,chautauqua lectures1 author's views on change in climate in1 #bdb1 #bdc ,chemical rays1 a manifestation of solar energy1 #di2 of light1 #eb ,china1 ,christmas ,day in1 #bgb1 #bgc ,china ,sea1 and monsoon winds1 #ajf ,chinook winds1 #ajg ,christmas in many climes1 #bff-bge ,circulation of air1 #ee2 general1 of wind1 #ih-aaa ,cirrus clouds1 #bhh ,civilization1 influence of climate on1 #bac-bbd2 mistaken idea of change of climate and1 #bbi2 must migrate with shifting of climatic belts1 #bdj ,cleveland1 ,president ,grover1 appoints ,prof4 ,moore chief of ,weather ,bureau1 #cjf ,climate1 #afa-ahg2 difference between weather and1 #afa2 changes in1 #afa2 how it is modified and controlled1 #ahh-bab2 its influence on civilization1 #bac-bbd2 has our1 changed81 #bbe-bdd2 influence of forests on1 #bdj-bdd2 controlling factors of ,american1 #bdc1 #bdd2 how to find the1 you seek1 #bdi-beb2 of ,cuba1 #beb1 #bec2 of ,porto ,rico1 #bec1 #bed2 of the ,hawaiian ,islands1 #bed1 #bee2 of the ,philippines1 #bee1 #bef2 of ,bermuda compared with ,florida and ,california1 #bef-bfa ,climates for health and pleasure1 #bde-bha ,climatic conditions1 optimum of1 favorable to man1 #bah1 #bai ,cloud1 temperature as affected by1 #agb2 formation and composition of1 #bhg1 #bhh2 difference between mist1 rain1 fog1 and1 #bhh2 fundamental formations of1 #bhh2 characteristics of the1 formations1 #bhh2 fog is1 at a low level1 #bhh ,cold1 contraction of air by1 #ae2 development of man favored by1 climate1 #bbd2 severest3 in ,north ,america1 #bgg1 #bgh2 in ,south ,america1 #bgh2 in ,europe1 #bgi2 in ,asia1 #bhj ,coldest and hottest places in the world1 #bge-bha ,cold storage1 efficient underground1 #ahc1 #ahd ,cold wave1 scavenger of the air1 #cf1 #cg2 beneficial effects of1 #cg2 great eddies in atmosphere1 #aah2 and speed of storm movement1 #abc-abf2 formation of1 #abd2 movement of1 #abe1 #abf2 detecting approach of1 #abe2 limitations on extent of1 #abf2 warnings of1 by ,bureau1 #abf1 #abg2 definition of1 #abg1 #abh2 maps showing zones of1 #abg1 #abh2 number of1 #abh1 #abi2 tempered by ,great ,lakes1 #abi1 #acj2 tempered by heat of large cities1 #acj1 #aca2 influenced by ,rocky ,mountain ,divide1 #aca2 ,weather ,bureau warnings of1 #cja1 #cjb ,colorado ,desert1 ,cal41 extreme heat in1 #bgg ,columbus1 ,christopher1 and the trade winds1 #ajb ,combustion1 rapid in liquid air1 #i2 nitrogen will not support1 #cc2 and oxygen1 #cd ,commerce1 benefits of ,weather ,bureau service to1 #cja1 #cjb ,condensation1 and variations in temperature1 #afc1 #afd1 #bhb-bij ,congelation1 #agd ,constantinople1 ,turkey1 ,christmas ,day in1 #bga ,continents1 circulation between oceans and1 #aje2 their influence on climate1 #aib-aih2 characteristics of temperature of interior of1 #aid1 #aie ,contour of land1 and frost1 #hf-ig ,convection1 and heat1 #ed1 #ee ,copper1 nucleus of atom of1 #cb ,coronas1 #ada ,cox1 ,prof4 ,j4 ,h41 and observations on frost1 #ic1 #id ,cranberry bogs1 and frost1 #ic-ie ,crime1 influence of weather conditions on1 #bae ,cuba1 climate of1 #beb1 #bec ,cultivation of land surface1 and frost1 #ic-ie ,cumulus clouds1 #bhh ,cushing1 comparison of temperatures by1 #aif1 #aig1 #bae ,cyclone1 general cause of1 #ih2 general whirl of1 #ajc2 gyration of1 #ajg-aji2 the disk of air constituting a1 #aai2 an area of low pressure1 #aai2 action of the air in and around the1 #abj2 movement of the1 #abj2 general extent of1 #ada2 destructive force of1 #adb ,cyclones1 localities in which1 are formed1 #aef1 #aeg ,dawson1 ,canada1 annual range of temperature at1 #afi ,death rate1 excessive humidity increases1 #baf1 #bag ,death ,valley1 ,cal41 intense heat in1 #bge-bgg2 area and forbidding character of1 #bgf2 temperature records taken in1 #bgf1 #bgg ,deflection1 due to earth's rotation1 #ajg ,density of earth's atmosphere at different levels1 #f 8,descriptive ,meteorology10 #ada2 reasons for change of opinion on change of climate expressed in1 #bcc ,desert of ,sahara1 ,africa1 intense heat in1 #bgi ,dew point1 #ch2 and frost1 #hi1 #ij ,diathermancy1 #ef1 #abd ,dirigible balloon1 as competitor of railroad1 #ai2 importance of developing the1 #bg ,disease1 elevation diminishes bacteria of1 #aj2 amelioration of1 by sunshine1 #bdh ,drainage1 influence on frost1 #id ,droughts1 the breaking of1 #acf ,dunwoody1 ,brig4 ,gen4 ,h4 ,h4 ,c41 expert forecaster and chief of ,weather ,bureau1 #cjf ,dust1 in the atmosphere1 #cc ,dust motes1 absence of1 at higher altitudes1 #i2 interference of sun's rays by1 #aj2 source of1 #dc1 #dd2 vary according to locality1 #dd2 counting of1 #dd1 #de2 and diffusion of light1 #de1 #df2 and twilight1 #df1 #dg ,eads ,bridge1 ,st4 ,louis1 freak of tornado and the1 #adg ,earth1 early condition of1 #a2 death of1 due to lack of heat from sun1 #c1 #d2 early condition of atmosphere of1 #e2 transmission of sun's rays to1 #g1 #h2 water vapor in atmosphere of1 #h2 four atmospheres of the1 #bi-dg2 comparison of heat of sun and of1 #dh2 circulation of winds and rotation of1 #ih-aaa2 deflection of winds due to rotation of1 #ajg-aji2 conditions if axis of1 were vertical1 #afd2 variations of heat of morning1 midday1 and evening1 #aff2 change of seasons and the1 #aff2 percentage of solar rays reaching the1 #aff-afh2 lag of temperatures of the1 #afh2 kept from freezing by water vapor1 #agj2 how the1 cools at night1 #aga1 #agb2 great heat of interior of the1 #agh1 #agi2 a poor reflector1 conductor1 and radiator1 #agi2 temperatures at various depths in the1 #agi2 warmer than air next above1 #ahj2 conditions if1 were all land1 #ahh-aij2 if axis of1 were perpendicular to plane of orbit1 #ahh1 #ahi2 conditions if1 were all water1 #aij-aib2 the real1 of land1 water1 and inclined axis1 #aib ,eclipse1 study of sun's atmosphere during1 #b ,efficiency1 weather conditions and human1 #baf2 maximum and minimum periods of human1 #bag1 #bah ,electricity1 and atoms1 #ca2 a manifestation of solar energy1 #di ,electron1 nucleus of all atoms1 #ca ,elements1 nuclei of atoms of various1 #ca1 #cb ,england1 second nation to establish weather service1 #big ,equator1 circulation of wind and temperature at1 #ii2 belt of calms at1 #ii ,equatorial currents1 #bjb1 #bjc ,equinoctial storm1 #adj ,equinox1 significance of1 #adj ,equinoxes 7,fig4 #ba71 #afc ,espy1 ,james ,p41 his theory of continuation of storms1 #aef1 #bif ,ether1 in outer space1 #g2 transmission of sun's rays by1 #g1 #h2 interstellar space filled with1 #dh2 man's ignorance of structure of1 #dh2 transmission of solar energy through1 #di ,eurasia1 cooling of continent of1 in winter1 #ajf2 extremes of temperature in continent of1 #aie-aig ,europe1 sections of1 where climatic conditions are best1 #bde2 hottest and coldest places in1 #bgi ,evaporation1 #eh1 #ei2 cooling effects of1 #gd2 and frost1 #ib2 lowers temperature of wet soil1 #ahj ,fahrenheit ,scale1 compared with ,centigrade1 #fg1 #fh ,floods1 influence of forests on1 #bdj-bdd2 flow of1 not restricted by forests1 #bdd ,florida1 climate of ,bermuda compared with that of1 #bef-bfa ,fog1 formation of1 #ib1 #bhh2 and frost1 #ib2 temperature as affected by1 #agb ,fhn winds1 #ajg ,forecasting1 general rules for1 #adi-aec2 importance of use of weather map in1 #adi2 the temperature by amateurs1 #adi1 #aea2 expectations of future1 #cjc1 #cjd2 fake1 #cjd ,forests1 exaggerated idea of influence of1 on climate1 #aih1 #bjj2 their influence on climate and floods1 #bdj-bdd2 the author's opinion on1 #bda2 as conservers of rainfall1 #bda2 mistaken idea of value of1 as conservers1 #bdc2 need of protection of1 #bdc2 restrict flow of moderate rainfall but not floods1 #bdd ,fossil remains1 as evidence of changes of climate1 #bci ,france1 third nation to establish weather service1 #big ,franklin1 ,benjamin1 his study and theory of storm movements1 #bic-bif ,freezing1 of fresh and salt water1 #agc-age2 height of1 cold in free air1 #ahe ,frost1 #he-ig2 causes of formation of1 #he2 light1 heavy and killing1 #hf2 dew point in relation to1 #hi1 #ij2 black1 #ij2 locality and immunity from1 #ij1 #ia2 conditions conducive to1 #ia2 ,weather ,bureau observations on1 #ia1 #ib2 evaporation and1 #ib2 cultivation of land surface and1 #ic-ie2 effect of sand covering on1 #id1 #ie2 dates of killing1 spring and fall1 #if1 #ig1 #bhg ,fuel1 proper humidity and conservation of1 #gc1 #gd ,galileo1 and the thermometer1 #bc1 #bib1 #bic ,gases of the atmosphere1 in mechanical not chemical union1 #cb2 importance of proper proportions of1 #cb ,geology1 evidence of changes of climate given by1 #bci ,germs1 in the atmosphere1 #cc ,glacial periods1 #bci ,glaciers1 movement of1 #fj2 recession and advancement of1 #bci ,glashier1 ,english meteorologist1 balloon ascension by1 #bj ,gold1 nucleus of atom of1 #cb ,gram-calorie1 unit of heat1 #ea ,great ,ice ,cap1 possible return of1 #bdj ,great ,lakes1 temper severity of cold waves1 #abi1 #acj2 benefit of ,weather ,bureau service to mariners on the1 #cjb ,greely1 ,gen4 ,a4 ,w41 chief of ,weather ,service1 #cjf ,gulf ,stream1 ,west ,indian hurricanes generally follow the1 #acc1 #bja2 influence of1 on climate1 #bjb1 #bjc2 source and course of1 #bjb1 #bjc2 individuality of the1 #bjc2 has no effect on climate of ,bermuda1 #beh1 #bei ,gyration1 due to earth's rotation1 #ajh1 #aji ,hail1 formation of1 #bhg2 and thunderstorms1 #bhg2 attempted prevention of1 #bij ,hailstones1 foreign matter in1 #bhd2 formation and size of1 #bhg ,halos1 cause and nature of1 #adj1 #ada2 lunar1 #ada ,harrington1 ,prof4 ,mark ,w41 first chief of new civil ,weather ,bureau1 #cjf ,havana1 ,cuba1 climate of1 #bec ,hawaiian ,islands1 climate of the1 #bed1 #bee ,haze1 nature and characteristics of1 #bhb ,hazen1 ,brig4 ,gen4 ,william ,b41 chief of ,weather ,service1 #cjf ,health1 north winds conducive1 south winds detrimental to1 #bf2 temperature in its relation to1 #baf2 semi-annual maximum and minimum periods of1 #bag1 #bah ,health seeker1 all-the-year climate for the1 #beb ,heat1 expansion of air by1 #ae2 possibility of using earth's interior1 #ah2 how it reaches the earth1 #df2 source of1 #di2 of sun and earth compared1 #dh2 manifestation and transmission of1 #dh1 #di1 #ea2 difference between temperature and1 #di1 #ej2 commercial and scientific unit of1 #ej1 #ea2 difference between waves of light1 sound1 and1 #ea2 conduction of1 #ed2 radiation of1 #ed2 convection of1 #ed1 #ee2 absorption of1 #ee1 #ef2 specific1 #ef2 latent1 #ef-eh2 differing temperatures with same solar1 #afb-aff2 great capacity of water for1 #bjj1 #bja2 ocean currents distributors of1 #bja1 #bjb2 extreme1 in ,death ,valley and ,colorado ,desert1 #bge-bgg2 in ,south ,america1 #bgh2 in ,africa1 #bgi2 in ,europe1 #bgi2 in ,asia1 #bgi1 #bhj2 in ,australia1 #bhj ,heat rays1 absorption of sun's1 #h ,heat waves1 difference between light1 sound1 and1 #ea2 length of1 #ea ,helium1 in earth's atmosphere1 #e1 #f2 importance of manufacture of1 #ai2 nucleus of atom of1 #ca ,henry1 ,prof4 ,joseph1 compiles first weather map1 #bif ,hersey1 ,lieut4 ,col4 ,henry ,b41 on dirigibles and airplanes1 #bh ,high-pressure belts1 rains of the1 #aje ,highs1 initiation of1 #aja2 placing of1 on weather map1 #aae1 #aaf2 characteristics of1 #abd2 conditions and action of air of1 #aca-acc2 periodicity of1 #acb2 and warm waves1 #acf2 influence of certain1 on climate1 #aib-aid ,himalaya ,mountains1 and monsoon winds1 #ajf1 #bjf2 and climate of ,asia1 #bjf2 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,verkhoyansk1 ,siberia1 extremes of temperature at1 #aif1 #aig2 ,christmas ,day in1 #bgc ,vienna1 ,austria1 ,christmas ,day in1 #bga ,v-shaped ,lows4 ,see ,,lows ,warm waves1 cause and duration of1 #acf1 #acg ,washington ,monument1 pressure of air at top of1 #gi ,water1 density of1 compared to air1 #ae2 infinitesimal size of molecule of1 #cj2 union of hydrogen and oxygen to constitute1 #cb2 and bacteria1 #dc2 commercial and scientific unit of heat and1 #ej1 #ea2 boiling point of1 #eh2 boiling point of1 as gauge for altitude1 #fj1 #fa2 frost as affected by body of1 #ij1 #ia2 rejects heat by reflection1 #agb2 solar rays penetrate1 #agc2 temperatures of large bodies of1 #agc2 difference in freezing temperature of fresh and salt1 #agc2 salt1 better conductor of heat1 #agc2 a wonderful phenomenon of fresh1 #agc-age2 low temperature of1 of ocean bottoms1 #age1 #agf2 temperature of1 of inclosed seas and oceans1 #agf1 #agg2 latitude1 season and depth change temperature of1 #agg1 #agh2 direction of wind affects shore temperature of1 #agh2 has great capacity for heat1 #bjj1 #bja ,water vapor1 and earth's atmosphere1 #h2 absorption of sun's rays by1 #h2 level of1 #h2 one of earth's atmospheres1 #bi2 density of1 #cg2 varies according to locality1 #cg1 #ch2 temperature and1 #ch2 precipitation of1 #ch1 #bca2 transformations of1 #ch2 and the dew point1 #ch2 saturation point and temperature1 #ch2 measured by hygrometer1 #ci2 and frost1 #he-ig2 protects earth from freezing1 #agj2 changes in sun's rays effected by1 #agj2 a separate atmosphere1 #bca2 and raindrops1 #bhd2 rainfall and instantaneous precipitation of all1 #bhe2 and snow1 #bhe-bhg2 and fog1 #bhh ,waves1 difference between light1 heat and sound1 #ea2 length of different1 of solar energy1 #ea2 velocity of1 #ea1 #eb ,weather1 forecasting1 with aneroid barometer1 #gd-gi2 moon has no influence on1 #ach-adj2 general rules for forecasting1 #adi-aec2 difference between climate and1 #afa2 changes daily1 #afa2 expectations of future forecasting of1 #cjc1 #cjd4 ,see also ,,united ,,states ,,weather ,,bureau 8,weather ,forecasting in the ,united ,states01 #aea ,weather map1 value of aviator in compiling1 #bc1 #aab-afj2 supplied by ,weather ,bureau1 #aab2 value of1 #aab1 #aac2 advantage of familiarity with1 #aac1 #aad2 method of compiling1 #aad2 collection of data for1 #aad1 #aae2 marking isobars on1 #aae2 ,highs and ,lows of1 #aae1 #aaf2 indication of storm action on1 #aae2 arrows fly with wind on1 #aaf1 #aag2 winter storm of #ahic on1 #aag-abc2 temperature readings on1 #aai2 indication of storm center on1 #aba2 meaning of red lines on1 #abb1 #abc2 forecasting tornadoes by use of1 #add1 #ade2 general rules for forecasting and the1 #adi-aec2 ,prof4 ,henry compiles first1 #bif4 ,see also ,,united ,,states ,,weather ,,bureau ,weather observers1 voluntary1 #ff-gi ,weather observations1 from kites1 #fd2 method of taking1 #ff-gi2 extent of area under1 #aee2 practice of early meteorologists in1 #aee1 #aef2 advantages enjoyed by the ,weather ,bureau in1 #aef-aeh4 ,see also ,,united ,,states ,,weather ,,bureau ,weather records1 serve ends of justice1 #gi-hc4 ,see also ,,united ,,states ,,weather ,,bureau ,weight1 difference between1 and pressure of air1 #gg ,wendham1 first to use multiple plane kites1 #fd ,west ,indian ,hurricane4 ,see ,,hurricane ,wheeling1 ,w4 ,va41 temperature of earth at depth of #cdij feet at1 #agi ,wilson1 ,president ,woodrow1 removes ,prof4 ,moore from office of chief of ,weather ,bureau1 #cjf ,wind1 and pressure of the globe1 #ih-aaa2 why it blows1 #aaf2 cause of variation in velocity of1 #aaf-aag ,winds1 trade1 #aja1 #ajb2 of middle latitudes1 #ajb1 #ajc2 rain1 of tropics1 #ajd1 #aje2 rain in the region of west1 #aje2 variations in coastal1 #ajf2 monsoon1 #ajf1 #ajg2 ,fhn1 #ajg2 ,chinook1 #ajg2 deflected by earth's rotation1 #ajg-aji2 velocity of1 as affected by altitude1 #aji-aaa2 ,west ,indian hurricane1 #acc1 #acd2 of ,galveston hurricane1 #acd2 of tornadoes1 #ada-adh2 of latitudes #cj north and south1 #aid ,winter resorts1 with favorable climate1 #bea ,winter storm of #ahic1 #aag-abc ,winter temperature gradients in isothermal stratum1 #ab ,xenon1 #cc ,yakutsk1 ,siberia1 annual range of temperature at1 #afi ,zero1 absolute1 #fb ,,footnotes3 #a ,unless otherwise expressed in this book it will be understood that all temperatures are recorded by the ,fahrenheit scale4 #b ,the author wishes that this were literally true1 for he believes that no great man or great woman ever was born from a mother with a painted face1 dyed lips1 false hair1 and a body pitifully distorted by ungracefully ambling about in high heeled shoes4 ,the power of suggestion is so great in its influence on the plastic mind of youth that a mother who is little else than a perambulating falsehood will leave descendants wanting in many if not all of the attributes of manly and womanly virtues4 #c ,john ,wiley ,sons1 ,new ,york4 #d 8,principles of ,human ,geography01 ,huntington and ,cushing4 ,john ,wiley ,sons1 ,new ,york4 ,,transcriber',s ,,note ,some ,charts and ,figures have been moved to be closer to the text paragraph they illustrate4 ,the very large wide multi-page table on relative humidity on pages #fi1 #gj and #ga has been split into seven parts to keep the width under #ge characters4 ,the wide tables on pages #bfb1 #bfc and #bfd have each been split into two parts4 ,obvious typographical errors and punctuation errors have been corrected after careful comparison with other occurrences within the text and consultation of external sources4 ,some hyphens in words have been silently removed1 some added1 when a predominant preference was found in the original book4 ,except for those changes noted below1 all misspellings in the text1 and inconsistent or archaic usage1 have been retained4 ,pg #ac3 #8important inform ion' replaced by #8important information'4 ,pg #bc3 #8co-operation of the' replaced by #8coperation of the'4 ,pg #fb3 #8temperature of #dei' replaced by #8temperature of -#dei'4 ,pg #fb3 #8and #bgc4a on the' replaced by #8and -#bgc4a on the'4 ,pg #gj3 ,table3 #8#bj' replaced by #8#cj' 7,temp#fc1 ,diff#ae74 ,pg #ga3 ,table3 #8#da' replaced by #8#ea' 7,temp#aab1 ,diff#ah74 ,pg #aca3 #8thousand of chimneys' replaced by #8thousands of chimneys'4 ,pg #afh3 #8depth of #bj4b1 and' replaced by #8depth of #bj4b1 and'4 ,pg #baj3 #8of ,pittsburg and' replaced by #8of ,pittsburgh and'4 ,pg #bad3 #8,humbolt says' replaced by #8,humboldt says'4 ,pg #cjj3 #8deductions thereform' replaced by #8deductions therefrom'4