1917 aviatortheweathe00carpiala

8/6/2019 1917 aviatortheweathe00carpiala

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UNIVERSITY OF CALIFORNIAAT LOS ANGELES


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ARMY AIRPLANE GLIDING TO NORTH ISLAND OVERU. S. CRUISER "SAN DIEGO"


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553Introductory Note

r~I~"1HIS is a brief but general account of the historyJ[ of aviation as it is associated with southern

California, a description of the War Depart-ment school of aviation at San Diego, a syllabus ofthe course of lectures delivered there on the subjectof practical meteorology as applied to aviation, anarrative of weather-study from an airplane, and arecital of subsequent active cooperation between theaviators and the U. S. Weather Bureau.*

Much of the material in the following pages wasobtained by the writer while detailed as Lecturer inMeteorology to the Signal Corps, War DepartmentAviation School at San Diego, in 1915-1916, alsowhen detailed in the same official capacity tothe U. S. Army Military Training Encampment,Monterey, 1916; and at the summer sessions of theUniversity of California during 1914-1916.Los ANGELES, CAL.,

February, 1917.

*It may be remembered that the weather service of the United Statesoriginated with the Signal Corps of the Army and that the WeatherBureau was created from it by Act of Congress, June, 1891, and made abureau of the U. S. Department of Agriculture. As a former member ofthe Signal Corps the writer enjoyed the renewal of old friendships amongthe officers at the Aviation School. Col. W. A. Glassford, Signal Corps,U. S. Army, Commandant of the War Department Aviation School atSan Diego, kindly read the manuscript of the following pages and thewriter gratefully acknowledges his valuable suggestions.

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ToJ. S. A.


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Table of ContentsCHAPTER I

The Signal Corps Aviation School at San Diego,California

CHAPTER IIApplied Meteorology for the Aviator . . .n

CHAPTER IIIWeather Observations from an Airplane . .16

CHAPTER IVInvestigating the Upper Air 25

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List of PlatesFigureNo. PageArmy airplane gliding to North Island over U. S.Cruiser "San Diego" Frontispiece1. Congressional Medal awarded Wright brothers . . 332. Ascent of sounding balloons at Avalon 343. Meteorograph which made the ascent of July 27, 1913 354. First flight of airplane carrying two persons .... 365. Sub-station at Mount Wilson Observatory 376. Type of airplane used in 191 1 on North Island . . 387. Discussing a flight 398. Captain Culver and parachute for determining wind-direction 409. Lieutenant Gorrell, U. S. Infantry, as observer ... 41

10. Point Loma from the eastern shore of North Island . 421 1 . San Diego, across Spanish Bight, from U. S. Aviation

School, at twilight 4312. Instructor Brindley and Meteorologist Carpenter in

Military Tractor No. 50 4413. Military Tractor No. 50 4514. "Trimming" Tractor No. 50 4615. Military Tractor No. 50 just before leaving the ground 471 6. San Diego harbor at over two thousand feet altitude 4817. San Diego viewed from an altitude of thirty-fivehundred feet 491 8. Military Tractor No. 50 viewed from the ground . . 5019. Flying Squad's Wind Direction Pennant Tower . . 5120. The Aviation School Motor-Boat "Pronto" .... 5221. U. S. Aviation Field at three thousand feet altitude . 5322. Repair Shop, U. S. Aviation School, San Diego, Cal. . 54

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The Aviator and theWeather Bureau

CHAPTER ITHE SIGNAL CORPS AVIATION SCHOOL ATSAN DIEGOHistory. The year 1911 marked the beginning

of the United States aviation school at San Diego.There is no finer tribute to the equability and generalexcellence of the climate of southern California thanthat given in the history of aeronautics. It was here,in 1900, that Chanute completed his early and epoch-making observations of the flight of gulls and peli-cans. These contributed largely to the success ofthe Wright brothers a few years afterward. It wasin southern California, six years ago, that Harkness,in an Antoinette, made his record monoplane flightto Tia Juana. San Diego witnessed the flying of thefirst seaplane, by Curtiss, five years ago. It is inthis district that not only the War Departmentaviation school and a number of commercial flyingschools are located, but also one of the large air-plane* factories in this country.Location of the School Whatever the final actionmay be as to permanent location, it has been con-

*Tbe National Advisory Committee for Aeronautics in its report ofOctober 17, 1916, on Nomenclature for Aeronautics, the name airplane issubstituted for "Any form of aircraft heavier than air which has wingsurfaces for sustention, with stabilizing surfaces, rudders for steering, andpower-plant for propulsion through the air."(7)


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Signal Corps Aviation School 9carried on by means of bi-daily lectures, while theearly morning hours are devoted to flying. Pilot-and-observer machines equipped with double controlare used in instruction. The aviation instructorascends with the student and allows him to manipu-late the controls, only resuming the management ofthe airplane in an emergency. Needless to say, thelife of an instructor is a most hazardous one and fullof thrills. His duty is to be on the alert to correcterrors in the manipulation of the machine. Afterevery trip the instructor reviews, point by point, thefeatures of the flight, showing the pupil his deficien-cies and explaining how he may avoid them in thefuture. The instruction is terse but kindly, and themanner of imparting this information leaves nothingto the imagination. After watching student andinstructor, and closely studying the finished work ofan aviator, it is my opinion that in no other occupa-tion must there be such perfect coordination betweenmind and muscle: the perfectly qualified aviator isthe modern super-man.*

Results oj a Year's Work. During the year 1915,the students of the aviation school made 3,652flights with a total time aloft of 1,516 hours, and amileage of 95,000. As regards weather conditionsaffecting flights, it will be found interesting tonote Chart No. 5 giving number of flights and dur-ation for the fourteen months ending August, 1916,which shows that work progressed regardless oif*Thc army aviator of today is picked for his quickness of mind andbody, and the first thing that strikes you about him is a sort of feline,wound-up-sprine alertness. Then you note his reticence, the cool reserveof a man whose lot is to express himself in deeds rather than words. And,lastly, there is the quiet seriousness, verging almost on sadness, of a manwho must hold himself ready to look death between the eyes at anymoment and yet keep his mind detached for other things. Lewis R.Freeman in the Atlantic Monthly.


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io The Aviator and the Weather Bureauweather, and at an increasing rate.* In February, amilitary tractor-seaplane (an all-California product),125-horsepower motor, with twenty-six gallons ofgasoline, four gallons of oil, and three passengers,making a total weight of 3,100 pounds, reached analtitude of 12,362 feet. This was the world's record,the previous altitude under the same conditionshaving been 9,000 feet.

*"It is estimated that the average cost to France of training eachpilot is five thousand dollars . . _ . no less than from four to six monthsare devoted to the training of finished pilots. Although I have just comefrom France, the progress of aviation is so rapid that much of my ownknowledge may be out of date before I again return to the front."C. D. Wmslow, "With the French Flying Corps," 1917, 4-5: N. Y.


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CHAPTER IIAPPLIED METEOROLOGY FOR THE AVIATORActivities of the Weather Bureau in Relation toAeronautics. Naturally the progress of aerial navi-

gation has at all times been rather closely connectedwith the Weather Bureau. For over a decade theBureau has not been content with surface observa-tions but has maintained laboratories for the studyof the upper air. The results of its observations areconsidered a mine of information for the studentaviator. Prof. Charles F. Marvin, the Chief of theWeather Bureau, is a member of the NationalAdvisory Committee for Aeronautics, and chairmanof a subcommittee engaged on the determination ofthe problems of the atmosphere in relation to aero-nautics.*The first official cooperation between the WeatherBureau and the War Department aviation schoolwas inaugurated in the year 1914 by Dr. W. J.Humphreys, Professor of Meteorological Physics,when he was detailed to give a course of lectures. Itwas during this course that he lectured on "Holes inthe Air."f This paper has been reprinted as a text-book for the aviation school.

Early Studies in Aeronautics. Unofficially, how-ever, the cooperation extended back some fifteenyears prior to that time, when the writer was incharge of the local office of the Weather Bureau atSan Diego, and assisted the aeronautical engineer,

*MonthIy Weather Review, 1915, 32:500, Washington.tPopular Science Monthly, 1914, 44:18-34, N. Y.

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12 The Aviator and the Weather BureauOctave Chanute, in his observations and experimentson San Diego Bay.* At this time hundreds of photo-graphs of sea-gulls, pelicans, and other soaring birdswere made, and both birds and photographs studiedand analyzed. Ever since then more or less interesthas been taken by the writer in aerial navigation.During an assignment to the Central Office the workof the Wright brothers was observed and studied.The association with the late Octave Chanute andhis friends, the Wrights, during their experimentalflights at Fort Meyer, Virginia, in September, 1908,is counted among the many pleasant memories ofthe Washington visit. It was here that was witnessedthe first flight with a passenger (see Fig. 4), Mr.Orville Wright taking up with him Major (nowColonel) George O. Squier, the present head of theaviation branch of the army. Such was the infancyof the flying-machine that at that date no fatalitieshad occurred. A few years later the writer had thepleasure of accompanying Mr. Glenn Curtiss whilehe was determining a site for his school, which wasfinally located on North Island. (See Fig. 6.)Shortly afterward, from this place, Harry Harknessmade record amateur cross-country flights in anAntoinette monoplane.

Active Work of the Weather Bureau. During thescore of years that the writer has been in charge ofthe San Diego and Los Angeles stations of theWeather Bureau, interest in flying has been cumu-lative. Efforts have been made to furnish aviatorswith available data so that at the present time a dayseldom passes without conference with officials or

""Climate and Weather of San Diego. "Carpenter, 1913, 57-59. San


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Applied Meteorology /or the Aviator 13students of Government or private flying schools inthis vicinity.Lectures on Meteorology as Applied to Aviation.Through the War Department, October, 1915, onrequest of the commanding officer of the SignalCorps aviation school, at San Diego, the writer wasdirected by the Chief of the Weather Bureau todeliver two lectures of which the following are out-lines:

"What the Weather Bureau Offers the Aviator"(Illustrated by 37 lantern-slides from photographs by the author)

Introductory:Weather service once part of the Signal Corps, U.S.A.Transfer in 1891 to the Department of Agriculture.Distribution of weather stations in the United States:

Character of data obtainable:Advance data from the daily map such asPosition of high and low areas.Weather conditions from sub-stations in vicinity.The weather map:How constructed.How distributed.Specimen maps showing differing conditions in California.Winds, velocity and frequency:On-shore.

Off-shore.Discussion of air conditions December 20-22, 1914.The international weather map.Relation to weekly forecasts.

Cardinal climatic features:Ascending winds and types producing them:Cloud, fog, precipitation.Descending winds:"Northers" and dust-storms.Thermograph and hygrograph traces.


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14 The Aviator and the Weather BureauFactors in the meteorology of southern California:Influence of latitude:

Sea.Mountains.Desert.Path and distribution of storm areas.

Knowledge of local climatology necessary in flying.Local winds discussed:"Woollies" (descending wind eddies)."Chubascos" (south coast thunder squall)."Santa Anas" (northeasterly and desiccating)."Wilmingtons" (northwesterly line-squall).

"Practical Meteorology for the Aviator"(Illustrated by 72 lantern-slides from photographs by the author)

Historical :Original work begun in Scotland, year 1749.Characteristics

English work; Dines' minute meteorograph.French work; Dr. Berson's balloon ascent of 6^ miles.German work; detailed data in low altitudes.American work began with Franklin.The Upper Air:Definition :"Stratosphere" is (according to some authorities) the

dynamical laboratory of the atmosphere where themain causes of pressure originate.Results in America:Balloon meteorograph (Fig. 3).Charts showing rate of increase in wind velocity withelevation (Chart No. 4).Wind, temperature, pressure, humidity at maximum air-plane height of 26,242 feet.

Stratosphere:Lower level in winter than in summer.Lower temperature in summer when surface pressure ishigh.Definition:"Troposphere" is the physical laboratory where cloudand rain are produced by local causes and inducedby the effect of the dynamical changes in the upper air.Conditions within 6 or 7 miles of the earth's surface.


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Applied Meteorology /or the Aviator 15Clouds and their Meaning :Cirrus:

Height and composition.Formation :Perpendicular shafts of clouds indicate rapid changesin weather.Horizontal layers, no change and clouds will dissipate.

Cirro-stratus, threatening in winter.Cirro-cumulus, fair and foul varieties differentiated.Cumulus with strong uplift.Alto-cumulus, cause of parallel rows.Fracto-cumulus, wind indicator, Point Loma "woolly."Stratus.Alto-stratus, favorable for flying.Strato-cumulus, long shallow rolls, threatening in winter.Cumulo-nimbus, unsafe air conditions for flying.Fracto-nimbus, waterspouts and their causes.Velo cloud, examples, cause, effect, distribution, density.Fog, examples of great fog-belts.


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CHAPTER IIINARRATIVE OF WEATHER OBSERVATIONSFROM AN AIRPLANEIn order to qualify as meteorologist competent toconfer with aviators, it seemed desirable to become

personally acquainted with some of the conditionsthat confronted them. As a matter of professionalacquirement therefore, I was glad to accept an in-vitation to go aloft after the necessary official ar-rangements had been made with Washington.This trip was in line with the previous endeavorsof applying practical meteorology to the science offlight and appropriately extended the work which wasbegun in San Diego with Chanute and the sea-gullsfifteen years before.

Object of Flight. I wished to put myself in thestudent's place and learn at first hand the practicalfacts he demanded from weather observations andto acquaint myself with everything possible thatmight be of value to an aviator. There were twodefinite things of which I desired knowledge: first,to determine the height of the upward trend of thesea-breeze over Point Loma which causes the mys-terious "woolly" of a score of years' acquaintancefrom a yachting standpoint; second, to observe theextent, form, and composition of the velo cloudwhich is the characteristic sun-cover of California.Preparations for the Ascent. Aviator InstructorOscar Brindley (the 1915 winner of the Curtisstrophy), in military tractor No. 50, was assigned

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Weather Observations from an Airplane 17as pilot. It may be stated here that the accepteddefinition of aviator is a pilot of a flying-machineheavier than air. The airplane used in my firstflight (see Fig. 13) was made in Los Angeles and isthe present standard army model. This tractor hasan 8o-horsepower engine and 8-foot propeller. It is21 feet long, has a wing-spread of 38 feet, supportingarea 364 square feet, and a flying radius, with twopersons, of 300 miles. The maximum altitude at-tained with this model at San Diego was 13,000 feet.Before being placed in service the machines arethoroughly gone over at the repair shop (see Fig. 22),and the motors are run at full speed for twenty-fourhours, after which they are taken down and subjectedto scrutiny for possible defects. All of the struts,guys, and wires are closely examined; the boltheadsare all drilled, wired, and soldered so that no amountof vibration will loosen them. Regardless of thelength of the flight, each machine, before going upagain, is given a rigid inspection and not until themechanicians have tested every part is it pronouncedready.^Not being prepared with a regulation aviationsuit, I was loaned a leather jacket by one officer, face-

goggles and safety helmet by others. I then tookmy place in the observer's seat forward and wasstrapped into it with the safety belt (see Fig. 12). Iwas cautioned to let my body give way as the waist-controls were moved from side to side and not payany attention to the steering rudder wheel whichhad a way of mysteriously revolving, advancing andreceding.In cranking an airplane, a certain formula isalways gone through. The mechanician at the pro-


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1 8 The Aviator and the Weather Bureaupeller calls out, "Close!" The aviator closes theswitch and repeats the word. This short-circuits theignition apparatus so that no spark occurs in thecylinders. The propeller is turned in order to intro-duce explosive mixtures into the cylinders. Whenready to start the mechanician says "Open!" Theaviator opens the switch and repeats the word. Thecharges in the cylinders then fire when the propelleris turned.

After the engine starts, the machine is "trimmed"by helpers and jockeyed for a favorable "take-off"into the air. (See Figs. 14, 15.) This model of air-plane climbs on a gradient i to 7; its minimum speedis 41 miles per hour. In other words, if the speed isless than 41 miles per hour the machine will not flyhorizontally.The Ascent. The tractor was headed into a 30-mile northwesterly wind so that the "take-off" wasquick and easy; there were only a few seconds spentrolling over the field, when the airplane left theground and I felt the never to be forgotten cushioningfeeling of the air. For ten seconds there was experi-enced a decidedly weakening nervous chill, whichoccurred to me once before when making a high divefrom a spring-board. It was the sort of physiologicaldisturbance that can only be counteracted by im-mediately pulling one's self together saying, "Well,here goes nothing!" The momentary depression wasimmediately followed by a corresponding elation offeeling which strange to say did not leave me duringthe trip and is always associated with thoughts ofthe journey. There was no dizziness, although I ampeculiarly susceptible to the least change in balance.The earth did not recede as we progressed steadily


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Weather Observations from an Airplane 19upward; we seemed part of the earth, but not of it.Although the airplane reached an altitude of 3,000feet in a comparatively few minutes, the barometerfalling from 30.0 to 27.0 inches, the decreased bodilypressure was not at all noticeable.*Next to the supporting quality of the atmosphereI had noticed the yo-mile blast of air as the airplanepushed its way steadily onward and upward. Natu-rally, the exhaust of the motor in addition to the roarof the wind made conversation impossible. Someairplanes have telephone communication betweenobserver and pilot. (See Fig. 9.) During one flightin a machine not so equipped, the passenger noticedthe breaking of some apparatus. Knowing that itwas impossible to make himself heard he hastilyscribbled the word "Accident!" on a bit of card,whereupon the pilot shut off his engine and glidedto earth.

Two-thousand Feet above Point Loma. Carryingout my suggestion as to investigating the "woolly,"the pilot drove the machine straight for Point Lomaand those unseen aerial breakers. Suddenly therewere two distinct "wallops" and I felt the fuselagebeneath me respond as if struck by a stuffed club.There was evidently first a surge then a drop, and itwas the descending current of air that deprived theairplane of the supporting medium, hence the shock.Point Loma itself, from this altitude, and seendirectly from above, looked very like a barracuda'sbackbone long, low, and ugly. Although this pen-insula (see Fig. 21) is less than 500 feet high it soeffectively deflects the prevailing northwesterly windthat the upward surge has been noticed by aviators

Trans-American Climatic Association, 1915, 31:20, Hot Springs, Va.


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2O The Aviator and the Weather Bureauat an altitude of 4,000 feet. It is no wonder thenthat these descending winds, called "woollies" (fromtheir churning the water into isolated masses whichlook like tufts of wool), are dreaded alike by yachts-men and birdmen. They have been known to carryaway topsails from too closely venturing schoonersand student aviators always give the vicinity ofPoint Loma a wide berth.No Winds Aloft. We had not changed our direc-tion since leaving the ground, but after passing overPoint Loma the airplane was put sharply on a portcourse. I had been expecting this and must confess,somewhat dreaded it, innocently thinking that a3O-miIe wind added to our yo-mile rate of speedwould "heel" the craft to an uncomfortable anglewhen the course was changed from northwesterly tosoutherly. What was my astonishment to find thatthe putting about was unaccompanied by any ofthe nautical motions such as tilting or canting. Theo-retically one may be ever so well grounded in physicallaws but it seems to take actual experience to bringtheir truth home to us. Of course there can be nowind in the air; when we entered the air it wasmoving 30 miles an hour in relation to the earthbut as soon as we were free from the earth the veloc-ity of the wind had no effect on our flight. Nomatter how strong the gale, so far as it concernedthe airplane, if the wind be steady no difficulty isexperienced; the aviator is concerned only by wind-shifts.

The Velo Cloud Seen from Above. In kindergartendays I remember that one of the first questions I askedwas "Are clouds smoke?" And this early query wasreally first answered in the air. Fog on a mountain


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Weather Observations from an Airplane 2 1top may be cloud, but somehow cloud free from closeproximity to the earth seems different.

The machine was put through the cloud blanketmuch as a horse takes a hurdle; it seemed unlikefog and more of a palpable substance. Aswe emerged,the sun was shining on it like a silvery sea withgently undulating surfaces and it looked for all theworld as supportable as layers of cotton-wool. Manytimes have cloud-banks from mountain tops beenobserved, yet the upper side of the velo cloud froma flying-machine looked very different. The cloudwas only four or five hundred feet thick and extendedinland a few miles in irregular outline. The seawardedges of the velo cloud were not ragged, and appar-ently paralleled the coast for 10 or 15 miles.Such was the exhilaration and confidence the airgave that I can understand how parachute jumpersconfidently step off into space, for to them the airis a supporting medium no more terrible than atransparent sea to a good swimmer. I believe thatthe record parachute drop was made in 1916 byColonel Maitland, of the English Royal FlyingCorps, who descended in a parachute 10,000 feetfrom an airplane. Fifteen minutes was occupied inthe descent.

Ease of Vision at 3,500 Feet Altitude. At thisaltitude the ease of vision is most remarkable. Atthis height, with perpendicular vision, the eye ispossessed of wonderful powers. In those "solitudesaugust with stars" men not only "mount up withwings as eagles" but are given the eagle's unob-structed vision. Birds have been credited with muchtoo keen vision. From this height of several thousandfeet every object stood out with remarkable distinct-


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22 The Aviator and the Weather Bureauness. Automobiles racing along the El Cajon boule-vard to Lakeside were readily picked up with theunaided eye although 20 miles away. Looking downover the aviation field the long compass mark andthe wind-direction pennant (Figs. 19 and 20) wereeasily distinguished. The bay and ocean, however,gave the most remarkable revelation, for the bottomof the bay and the shallow ocean shore were plainlydiscernible. The absence of water as well as airrefraction explains why submarines cannot hidefrom an airplane: one of the army aviators told methat a submarine cannot ordinarily sink so low thatit cannot be seen from an airplane.Color of Landing-ground Important. Owing tothe absorption and reflection of sunlight, there is adistinct variation in the character of otherwise simi-lar landing-ground. A field, dark from recent plowing(or burning), will heat the air over it faster tnan willa field of stubble, hence over the former field therewill be the greater air disturbance, and this willaffect the ease of landing. Air is heated by contactand convection. One of the aviators said that re-cently he was descending, and had all but reachedthe ground when a localized convectional currenthurled his machine upward some distance but im-mediately afterward deposited him on the groundwithout damage.

Spiraling Down 5,000 Feet. Speeding ever in widecircles the course lay southeast over the upper partof San Diego Bay. The city of San Diego presentedthe usual checkerboard appearance (Fig. 16), andeven at this altitude it would seem easy to drop anorange at almost any point. The velp cloud waslifting and we could see the gradual disappearance


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Weather Observations from an Airplane 23as it melted rather than drifted from North Island.(See Fig. 17.)The gliding descent was made from an altitude of2,500 feet, starting above San Diego. As the aviationschool was approached, we could see a number ofmachines in the air, three below and two above us,circling about like hawks. And, like soaring birds,these machines had

_their air-lanes, designatedcourses and levels being devoted to the different

classes of machines. The landing was made withoutincident and the hour's flight was ended.Outline of Meteorological Work at the AviationSchool. At the close of the lecture detail, the atten-tion of the student aviators was called to the impor-tance of their having as thorough knowledge as pos-sible of the fundamentals of meteorology. The appli-cation of these fundamentals to the analysis of airconditions met with in their daily flights was shownto be essential. Investigations as to varying winddirection were taken up by one of the staff instructorsby the use of small parachutes to be dropped atdifferent altitudes. (See Fig 8.) Through thecooperation of the local official in charge of the SanDiego Weather Bureau station, duplicate signalsheets were available from which the student officersmade their local weather maps. From these mapsand their own flights, they could arrive at some rela-tionship between the actual and the theoretical 3,000-and io,ooo-foot level maps prepared from the Bige-low formula, as used by the Bureau. Lectures weregiven on temperature and its distribution; winds,moisture, and clouds were also made part of thecourse, one of the papers of the Bureau* being re-

*"CIouds of California," Carpenter, 1914, 24, ad ed., Ft. Leaven*worth (U. S. Army Press).


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24 The Aviator and the Weather Bureauprinted by the aviation school by permission of theChief of the Bureau and used as a textbook. TheWeather Bureau furnished the station with a stan-dard set of meteorological instruments so that thestudent officers could become perfectly familiarwith the regular equipment at the Weather Bureaustations.

Extending the Usefulness^ of the Bureau to theAviators. Practical utilization by the aviators ofthis district of the information possessed by theBureau has received considerable impetus during thepast six months. During the cross-country flightsof April and May, 1916, the Los Angeles station wasdirected by the Chief of Bureau to furnish weatherand flight condition^ between San Diego and LosAngeles. With the aid of the general weather-mapdata from the regular stations, and special observa-tions of wind, weather, and fog conditions on theimmediate coast near Los Angeles, and on MountWilson, it was possible to issue satisfactory forecastsof

^ flying conditions. The eye-observations of fog-heights as determined by the Weather Bureau co-operative station at the Mount Wilson Solar Obser-vatory were especially valuable. From this moun-tain (6,000 feet elevation) it is possible on a good dayto see the whole length of the coast from Point Fir-min, San Pedro harbor to Point Loma, San DiegoBay. Knowing different levels, the observer atMount Wilson was able to give actual thickness andextent of the fog-belt and its past twenty-four-hourhistory.


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Investigating the Upper Air 27

Charts Showing Upper-air Weather Conditions.It is believed that the following charts when exam-ined in connection with the accompanying expla-nation in the text will give the reader something of anoutline as to the conditions existing in the upperregions of the atmosphere.


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CHART NO. 2Vertical Temperature Gradient, Avalon,

California, July 27, 1913Solid line represents the ascent of the recording apparatus, the dottedline the descent. (Verticals 25 C. or 45 F.)

Reproduced from the Monthly Weather Review, 42: 412


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CHART NO. 3Mean Vertical Tem-perature GradientFigure reproduced fromMonthly Weather Review,

42: 413-Altitude values are inkilometers at the left, andin miles at the right. Tem-perature values are in Cen-tigrade at bottom, in Fah-renheit at top.

Maximum airplane alti-tude 26,242 feet or 5 miles.

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CHART NO. 4Diagram Showing Increase of Wind with Elevation

Data from Eight MeteorographsFrom the article "Free Air Data in Southern California, July andAugust, 1913" by Dr. Wm. R. Blair, Professor of Meteorology, in theMonthly Weather Review, for July, 1914, it is learned that the wind shiftsfrom west to east rather abruptly at 16 to 20 km. (10 to 12 miles); belowthis level down to about 5 km. (3 miles) it is quite uniformly from thewest. Extremes: Maximum wind velocity 21.2 miles, 5,000 meterselevation, 5 P.M., July 24; minimum wind velocity 0.8 miles, 1,500 meters

27.eady increase in velocity of the wind with elevation.elevation, 5 P.M., July 24; mi:elevation, 5 P.M., July 27.The table shows a steady i . .data being obtained from the eight meteorographs. There were four

ning flights (July 31, August 3, 7, 8) and five afternoon flights (July27, August 3, 7, 8, 1913), and elevations were computed for nine

eights, 1,000 to 5,000 meters. Beyond the 5,000 meters the records showthe data beingmorn'Ni...at from' 2 to 7'miles altitude the wind increases at approximately thesame rate that the density of the air decreases.

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CHART NO. 5Chart Showing Number oj Flights and Duration inHours for the Months of July to December, 1915,and January to August, 1916

Prepared by the War Department, Signal Corps Aviation School, SauDiego, California, and furnished through the courtesy of Col. W. A.Glassford, Signal Corps, U. S. Army, Commanding Officer, September

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FIG. I. CONGRESSIONAL MEDAL AWARDED WRIGHT BROTHERS(Designed by Morgan)

This medal was awarded Orville and Wilbur Wright by res9lution ofCongress, March 4, 1909. Bronze replica in possession of the writer.

Pbotograpbed M


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FIG. 2. ASCENT OF SOUNDING-BALLOONS AT AVALONPhotographed July 2-7, 191 j

This set was liberated from the base of the U. S. Weather Bureau,Avalon, Catalina Island, California, at 4.57 P.M., July 27, 1913, and roseto a height of 23,870 meters in one hour and three quarters when one ofthe balloons burst and the descent began. This was observed by Carpenterat the theodolite.


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FIG. 3. METEOROGRAPH WHICH MADE THE ASCENTOF JULY 27, igi3

Photographed August, 1913This meteorograph rose to a height of 23,870 meters (94,716 feet), atwhich height the pressure was 23 mm. (0.906 inches), temperature -52. 1 C(-58 F.), relative humidity 21 per cent, wind E. (or more precisely S. 79degrees E.), velocity 6.1 m.p.s. (14 miles per hour), but the minimumtemperature was registered at 1 5,228 meters (49,960 feet) when the thermom-eter showed -64.7 C. (-85 F.), at which time the pressure was 89 mm.

(3.504 inches of the barometer), relative humidity 19 per cent, wind N.W.,3.4 m.p.s. (8 miles per hour).The basket was picked up at sea off Oceanside, San Diego County,about 90 km. (145 miles) east of Ayalon.For the first 6 miles of ascension the balloon moved upward at therate of 8 miles per hour.

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FIG. 6. TYPE OF AIRPLANE USED IN 1911 OPhotographed October, 1911

This photograph of Mr. Glenn Curtiss in his "pusher" airplane wasmade shortly after the Curtiss School of Flying was established in 1911,on North Island. At his right is Local Forecaster Carpenter.Comparison of this machine, which four years ago was the last wordin airplanes, with the tractor shown on the opposite page, indicates therapid progress in design.

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FIG. 7. DISCUSSING A FLIGHTPhotographed October 18, iQif

Aviation Instructor Oscar Brindley discussing a flight with CaptainClarke, U. S. A., and other officers at the U. S. Aviation School at SanDiego.Mr. Brindley is standing by the side of Captain Clarke in the group at

ight. After every fligTit the Instructor reviews, point by point, thehefeatures of the flight, showing the pupil his deficihe may avoid them in the future.The officer at the left, Lieutenant Brown, has the regulation leatherleggings, coat and helmet, and is ready to go up as soon as the mech(who may be seen at the extreme left) finish insthe airplane fit for the next flight.

ies and explaining how

spection and pronounce

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FIG. 8. CAPTAIN CULVER AND PARACHUTEPhotographed October 21, iQif

Captain C. C. Culver. U. S. Cavalry, Adjutant, Ayjrachute in his hand, having word with Captain L.S. A., before the latter"s flight. The object of the parachute is tom School, with aW. Patterson,

determine changing wind-direction at different heightThe airplane wireless record is now held by Captain Culver. In October,1916, he sent a message 119 miles from Santa Monica to San Diego, Cali-fornia, while flying at an altitude of I Yi miles. He received a radio messagedistance of 1 1 miles whilimessages while in flightpounds.

vhile flying 7,000 feet aloft. He is also the firsto airplanes so that they could exchangeradio set used weighed less than forty-fivemilitary aviator to rig up two airplanes so that they could exchangeThe ra '* " * i i i -i r - tL

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FIG. 9. LIEUTENANT GORRELL, U. S. INFANTRY, AS OBSERVERPhotographed October, 1915

The noise of the motor, together with the terrific blast of air, makesconversation impossible between the pilot and observer; for that reasontelephones are sometimes installed as noted in this photograph.Lieut. Edgar S. Gorrell is shown as the observer in this photograph.He has since qualified as an aviator and made a brilliant record in theMexican activities in 1916.

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FIG. 18. MILITARY TRACTOR No. 50 AT 3,500 FEET ALTITUDEPhotographed October 20, 191f

The airplane, in which the pilot, Oscar Brindley and the observer,Meteorologist Carpenter, made their flight, was photographed at themaximum elevation, 3,500 feet above the aviation field.

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FIG. 19. FLYING SQUAD'S WIND-DIRECTION PENNANT ON TOWERPhotographed October ;, 1915

The regular observation tower from which all observations and noteson every flight are made is just back of the headquarters building. Thestation anemometer is on the tower, and the portable anemometer is tothe left.


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This book is DUE on the last date stamped below

**

Form L-9-35-m-8,'


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3 115800938 8298

UC SOUTHERN REGIONAL LIBRARY FACILITYHi I II III 1 1

A 001 039 170 4


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1917 aviatortheweathe00carpiala

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