BUREAU***


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[Illustration: ARMY AIRPLANE GLIDING TO NORTH ISLAND OVER U. S. CRUISER
“SAN DIEGO”]


THE AVIATOR AND THE WEATHER BUREAU

by

FORD A. CARPENTER, LL.D.

Meteorologist

Illustrated with Photographs and Charts
by the Author and Others






Published by the
San Diego Chamber of Commerce
1917

Published by permission
Dated August 25, 1916

Second edition, 5,000 copies

J. Horace McFarland Company
Mt. Pleasant Press
Harrisburg, Pennsylvania




Introductory Note


This is a brief but general account of the history of aviation as
it is associated with southern California, a description of the War
Department school of aviation at San Diego, a syllabus of the course
of lectures delivered there on the subject of practical meteorology as
applied to aviation, a narrative of weather-study from an airplane, and
a recital of subsequent active coöperation between the aviators and the
U. S. Weather Bureau.[A]

    [A] It may be remembered that the weather service of the
        United States originated with the Signal Corps of the Army
        and that the Weather Bureau was created from it by Act
        of Congress, June, 1891, and made a bureau of the U. S.
        Department of Agriculture. As a former member of the Signal
        Corps the writer enjoyed the renewal of old friendships
        among the officers at the Aviation School. Col. W. A.
        Glassford, Signal Corps, U. S. Army, Commandant of the War
        Department Aviation School at San Diego, kindly read the
        manuscript of the following pages and the writer gratefully
        acknowledges his valuable suggestions.

Much of the material in the following pages was obtained by the writer
while detailed as Lecturer in Meteorology to the Signal Corps, War
Department Aviation School at San Diego, in 1915–1916, also when
detailed in the same official capacity to the U. S. Army Military
Training Encampment, Monterey, 1916; and at the summer sessions of the
University of California during 1914–1916.

  LOS ANGELES, CAL.,
   February, 1917.




     _To_
  _J. S. A._




Table of Contents


  CHAPTER I

  The Signal Corps Aviation School at San Diego, California            7


  CHAPTER II

  Applied Meteorology for the Aviator                                 11


  CHAPTER III

  Weather Observations from an Airplane                               16


  CHAPTER IV

  Investigating the Upper Air                                         25




List of Plates


  Figure
   No.                                                              Page
      Army airplane gliding to North Island Over U. S. Cruiser
          “San Diego”                                _Frontispiece_

   1. Congressional Medal awarded Wright brothers                     33

   2. Ascent of sounding balloons at Avalon                           34

   3. Meteorograph which made the ascent of July 27, 1913             35

   4. First flight of airplane carrying two persons                   36

   5. Sub-station at Mount Wilson Observatory                         37

   6. Type of airplane used in 1911 on North Island                   38

   7. Discussing a flight                                             39

   8. Captain Culver and parachute for determining wind-direction     40

   9. Lieutenant Gorrell, U. S. Infantry, as observer                 41

  10. Point Loma from the eastern shore of North Island               42

  11. San Diego, across Spanish Bight, from U. S. Aviation School,
        at twilight                                                   43

  12. Instructor Brindley and Meteorologist Carpenter in
        Military Tractor No. 50                                       44

  13. Military Tractor No. 50                                         45

  14. “Trimming” Tractor No. 50                                       46

  15. Military Tractor No. 50 just before leaving the ground          47

  16. San Diego harbor at over two thousand feet altitude             48

  17. San Diego viewed from an altitude of thirty-five hundred
        feet                                                          49

  18. Military Tractor No. 50 viewed from the ground                  50

  19. Flying Squad’s Wind Direction Pennant Tower                     51

  20. The Aviation School Motor-Boat “Pronto”                         52

  21. U. S. Aviation Field at three thousand feet altitude            53

  22. Repair Shop, U. S. Aviation School, San Diego, Cal.             54




The Aviator and the Weather Bureau




CHAPTER I

THE SIGNAL CORPS AVIATION SCHOOL AT SAN DIEGO


_History._--The year 1911 marked the beginning of the United States
aviation school at San Diego. There is no finer tribute to the
equability and general excellence of the climate of southern California
than that given in the history of aëronautics. It was here, in 1900,
that Chanute completed his early and epoch-making observations of the
flight of gulls and pelicans. These contributed largely to the success
of the Wright brothers a few years afterward. It was in southern
California, six years ago, that Harkness, in an Antoinette, made his
record monoplane flight to Tia Juana. San Diego witnessed the flying
of the first seaplane, by Curtiss, five years ago. It is in this
district that not only the War Department aviation school and a number
of commercial flying schools are located, but also one of the large
airplane[B] factories in this country.

    [B] The National Advisory Committee for Aëronautics in
        its report of October 17, 1916, on Nomenclature for
        Aëronautics, the name _airplane_ is substituted for “Any
        form of aircraft heavier than air which has wing surfaces
        for sustention, with stabilizing surfaces, rudders for
        steering, and power-plant for propulsion through the air.”

_Location of the School._--Whatever the final action may be as to
permanent location, it has been conceded by all authorities that
the situation of the aviation school on North Island, San Diego Bay,
is ideal. (See Fig. 21.) The so-called island is connected with the
peninsula of Coronado by a narrow sand-spit, and it comprises many
hundred acres of level land free from buildings and any sort of
overhead wires. The island fronts the ocean on the south; Point Loma on
the west with the narrow entrance to the bay between; to the north is
the city of San Diego across the bay; and Coronado just beyond Spanish
Bight on the east. This natural arrangement gives good air conditions
for beginners, and also enables them to use the smooth waters of the
bay as well as the rough ocean water for the seaplanes. The proximity
of this location to San Diego is also a distinct advantage. (See Fig.
11.) All of the structures of the aviation school on North Island are
temporary, the buildings consisting of a scattering array of huge sheds.

_Character of Instruction._--Officers from all branches of the army
volunteer for this service. The qualifications of an aviator are
caution, judgment, and technical skill. Deficiencies in caution and
judgment being temperamental are rarely remedied, while technical
skill is largely a matter of acquirement. Less than ninety days are
allowed for qualification as a junior aviator, and if in that period
the officer’s deficiencies are found to be inherent, he returns to his
company.

The school is a place for hard work and quick thinking. Detail in the
repair shop is part of the course, as is also the use of the gasoline
engine in motor trucks as well as in aircraft. (See Fig. 22.) Theory
and practice are closely united: the former is carried on by means
of bi-daily lectures, while the early morning hours are devoted to
flying. Pilot-and-observer machines equipped with double control are
used in instruction. The aviation instructor ascends with the student
and allows him to manipulate the controls, only resuming the management
of the airplane in an emergency. Needless to say, the life of an
instructor is a most hazardous one and full of thrills. His duty is to
be on the alert to correct errors in the manipulation of the machine.
After every trip the instructor reviews, point by point, the features
of the flight, showing the pupil his deficiencies and explaining how
he may avoid them in the future. The instruction is terse but kindly,
and the manner of imparting this information leaves nothing to the
imagination. After watching student and instructor, and closely
studying the finished work of an aviator, it is my opinion that in no
other occupation must there be such perfect coördination between mind
and muscle: the perfectly qualified aviator is the modern super-man.[C]

    [C] The army aviator of today is picked for his quickness of
        mind and body, and the first thing that strikes you about
        him is a sort of feline, wound-up-spring alertness. Then
        you note his reticence, the cool reserve of 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 man who must hold himself ready to look
        death between the eyes at any moment and yet keep his
        mind detached for other things.--Lewis R. Freeman in the
        _Atlantic Monthly_.

_Results of a Year’s Work._--During the year 1915, the students of the
aviation school made 3,652 flights with a total time aloft of 1,516
hours, and a mileage of 95,000. As regards weather conditions affecting
flights, it will be found interesting to note Chart No. 5 giving
number of flights and duration for the fourteen months ending August,
1916, which shows that work progressed regardless of weather, and at
an increasing rate.[D] In February, a military tractor-seaplane (an
all-California product), 125-horsepower motor, with twenty-six gallons
of gasoline, four gallons of oil, and three passengers, making a total
weight of 3,100 pounds, reached an altitude of 12,362 feet. This was
the world’s record, the previous altitude under the same conditions
having been 9,000 feet.

    [D] “It is estimated that the average cost to France of
        training each pilot is five thousand dollars... no less
        than from four to six months are devoted to the training
        of finished pilots. Although I have just come from France,
        the progress of aviation is so rapid that much of my own
        knowledge may be out of date before I again return to the
        front.”--C. D. Winslow, “With the French Flying Corps,”
        1917, 4–5: N. Y.




CHAPTER II

APPLIED METEOROLOGY FOR THE AVIATOR


_Activities of the Weather Bureau in Relation to
Aëronautics._--Naturally the progress of aërial navigation has at all
times been rather closely connected with the Weather Bureau. For over
a decade the Bureau has not been content with surface observations
but has maintained laboratories for the study of the upper air. The
results of its observations are considered a mine of information for
the student aviator. Prof. Charles F. Marvin, the Chief of the Weather
Bureau, is a member of the National Advisory Committee for Aëronautics,
and chairman of a subcommittee engaged on the determination of the
problems of the atmosphere in relation to aëronautics.[E]

    [E] Monthly Weather Review, 1915, 32:500. Washington.

The first official coöperation between the Weather Bureau and the War
Department aviation school was inaugurated in the year 1914 by Dr.
W. J. Humphreys, Professor of Meteorological Physics, when he was
detailed to give a course of lectures. It was during this course that
he lectured on “Holes in the Air.”[F] This paper has been reprinted as
a textbook for the aviation school.

    [F] Popular Science Monthly, 1914, 44:18–34, N. Y.

_Early Studies in Aëronautics._--Unofficially, however, the coöperation
extended back some fifteen years prior to that time, when the writer
was in charge of the local office of the Weather Bureau at San Diego,
and assisted the aëronautical engineer, Octave Chanute, in his
observations and experiments on San Diego Bay.[G] At this time hundreds
of photographs of sea-gulls, pelicans, and other soaring birds were
made, and both birds and photographs studied and analyzed. Ever since
then more or less interest has been taken by the writer in aërial
navigation. During an assignment to the Central Office the work of
the Wright brothers was observed and studied. The association with
the late Octave Chanute and his friends, the Wrights, during their
experimental flights at Fort Meyer, Virginia, in September, 1908, is
counted among the many pleasant memories of the Washington visit. It
was here that was witnessed the first flight with a passenger (see Fig.
4), Mr. Orville Wright taking up with him Major (now Colonel) George O.
Squier, the present head of the aviation branch of the army. Such was
the infancy of the flying-machine that at that date no fatalities had
occurred. A few years later the writer had the pleasure of accompanying
Mr. Glenn Curtiss while he was determining a site for his school, which
was finally located on North Island. (See Fig. 6.) Shortly afterward,
from this place, Harry Harkness made record amateur cross-country
flights in an Antoinette monoplane.

    [G] “Climate and Weather of San Diego,” Carpenter, 1913, 57–59,
        San Diego.

_Active Work of the Weather Bureau._--During the score of years that
the writer has been in charge of the San Diego and Los Angeles stations
of the Weather Bureau, interest in flying has been cumulative. Efforts
have been made to furnish aviators with available data so that at the
present time a day seldom passes without conference With officials or
students of Government or private flying schools in this vicinity.

_Lectures on Meteorology as Applied to Aviation._--Through the War
Department, October, 1915, on request of the commanding officer of the
Signal Corps aviation school, at San Diego, the writer was directed by
the Chief of the Weather Bureau to deliver two lectures of which the
following are outlines:


“_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 as
        Position 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.

  Factors 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 6½ 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 the
        main causes of pressure originate.
    Results in America:
      Balloon meteorograph (Fig. 3).
      Charts showing rate of increase in wind velocity with
        elevation (Chart No. 4).
      Wind, temperature, pressure, humidity at maximum airplane
        height of 26,242 feet.
      Stratosphere:
        Lower level in winter than in summer.
        Lower temperature in summer when surface pressure is
          high.
    Definition:
      “Troposphere” is the physical laboratory where cloud
        and rain are produced by local causes and induced
        by the effect of the dynamical changes in the upper air.
      Conditions within 6 or 7 miles of the earth’s surface.
  Clouds and their Meaning:
    Cirrus:
      Height and composition.
      Formation:
        Perpendicular shafts of clouds indicate rapid changes
          in 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