in authority as well as designers, manufacturers, and mechanics, must be held responsible for a large part of the disappointing results of engine and plane production. But a still larger amount of the disappointment the country experienced from the failure of production to meet expectations must be assigned to causes that were inevitable and for which no just condemnation will lie (3539, 3540).

BOLLING COMMISSION

After war was declared Brig. Gen. Squier suggested that experts in aeronautical matters be sent overseas to gain the benefit of the European experience in engine and airplane matters. This led to the appointment of the Bolling Commission, of which Col. R. C. Bolling was the head, which left the United States on the 17th of June 1917 (2910-XXVIII-XXIX, 210), and arrived in England on the 26th of June. The commission was made up of naval and Army members and civilian experts, including 93 American mechanics (2910-XXX). These mechanics were placed in European factories for the purpose of obtaining intimate, practical knowledge of the construction of service airplanes and engines, and with a view of accommodating European construction to American methods of manufacture and returning to supervise and direct American factories (214).

The membership of the Bolling Commission was selected from what was believed to be men best qualified to judge and profit by European experience in various phases of European production (214, 210, 2910-XXIX-XXX).

The commission visited England, France, and Italy. In each country they immediately got in contact with the head of aircraft matters, investigated the aircraft and engine factories, selected the designs of engines, planes, and equipment they thought best adapted to American use and production, and made arrangements for the shipment of samples thereof to the United States. Their investigation also included visits to the western and Italian fronts. Questions concerning the right to the use of foreign inventions somewhat delayed the use of these foreign machines and equipment by the United States. The English samples of engines, planes, and equipment were shipped on the 4th of July, 1917. The machines and material were promised to be shipped by France (2910-XXXIX) on the first boat following the 6th of July, 1917. Shipment was delayed, however, principally on account of the contention of the holders of inventions for compensation, and shipments were not made until August. The Spad machine which had been promised was not shipped until the 28th of August and did not arrive in the United States until the 18th of September, 1917 (2910-XL). Negotiations for the adjustment of the royalties with the French Government were finally dropped and later adjustment was made with the owners of the patents (2910XLI).

Italy gave the Bolling Commission a particularly friendly and helpful reception and promised, and promptly shipped, all the samples of engines, planes, and equipment desired (2910-XL-XLI).

The shipments of these samples were made for the information of the American mechanics and as models for such thereof as might subsequently be determined upon for quantity production.

The efforts of Col. Bolling led to the establishment of an Interallied Aircraft Convention which met at Paris at least once a month. As a result, closer contact and cooperation was established between the Allies in aircraft matters and the judgment of this convention largely determined the aircraft programs of the different allied countries subsequent to that time (213). The American representatives urged that all the allied countries exchange manufacturing rights during the war. England accepted that principle except for the Rolls-Royce engine, over which the Government did not have control (2910-XXXIII, XL, XLI).

After the Bolling Commission investigated conditions in Europe and became more familiar with the production experiences of the belligerents in the war, it was found, and agreed with the allied advisers and confirmed by allied nations, that as far as aircraft production was concerned, America's efforts outside of training planes should be devoted to the manufacture of the heavier types of airplanes and engines, which meant observation planes such as DH-4 and bombing planes such as the Handley-Page, leaving the production of pursuit planes, such as the Spad, to Europe, which pursuit production would supply the needs of the United States.

RECOMMENDATIONS FOR PRODUCTION

The program finally recommended to the United States by the Bolling Commission represented the unanimous judgment of the Bolling Commission, the allied advisers, and Pershing's staff (211, 2910-XLI-XLII). However, aircraft programs among any of the Allies never reached a stabilized stage during the war. The French changed their aircraft program 18 times during the first 3 years of the war (2910-LI). The evolution of the service plane, as well as the inexperience of the designers, and producers for America, led to frequent changes more or less expensive and confusing, and causing delay. The history of the war, however, perhaps justifies the observation that the experiences of the United States in that regard were not particularly distinguishable from the experience of our allies, particularly as the United States entered the war the least prepared in aircraft matters of all the principal belligerents.

Subsequent conditions convinced the commission that some of its recommendations were erroneous, particularly as to the Spad Monosoupape or rotary engine and the Caproni triplane, the use of which proved to be impracticable (2910-XLII-XLIII, LI-III, 215).

The production of the other Spad with a fixed engine was recommended and was subsequently canceled under circumstances hereinafter explained.

The final recommendation was for the Handley-Page or the Caproni biplane as a heavy bombing machine instead of the Caproni triplane (215). The Bristol Fighter, with 200-horsepower Hispano engine, was recommended for a two-place pursuit machine. The American effort to manufacture it proved a failure. The DH-4 was recommended to be manufactured as a stop-gap machine until the DH-9 in course of development by the English demonstrated its success (211). While the Bolling Commission was in France, that Government endeavored to secure a contract with the United States for the manufacture of 20,000 airplanes and 30,000 engines (2910XXXIX). Subsequently a contract was made for 5,000 airplanes

and 8,500 engines (2910-XCIV). France was unwilling to perform this agreement (67, 226). Only two planes were delivered under this contract, which was superseded by contract of May 3, 1918 (2910– XCIV).

The question of how America could best aid the aircraft program was considered, including the question as to whether it could best be done by the shipment of materials or by the manufacture of parts for French or English machines, or by the completed manufacture of American machines, to be finally assembled in Europe. A compromise of these methods was eventually adopted, under which the American program included the complete manufacture of some engines and machines and the partial manufacture of others in the United States, and furnishing materials and mechanics for Euro

pean construction.

The Bolling Commission dissembled about the 15th of August, 1917, part of its members returning to the United States and part remaining with the American Expeditionary Forces.

APPROPRIATIONS

Congress made ample appropriations for the Aircraft Service during the war, the aggregate amount of which, with about $15,000,000 appropriated during the year preceding the war, aggregated $1,700,000,000. On account of the termination of the war, appropriations were revoked prior to June 30, 1919, aggregating $487,000,000. The aggregate expenditures and obligations to June 30, 1919, were $1,055,652,147.66.

Prior to June 30, 1918, total expenditures were about $273,000,000, of which approximately $165,000,000 was for training fields and training and operating purposes. Up to that time about $208,000,000 had been spent for the following items: 8,488 airplanes, 12,626 engines, 411 balloons, 115,655 instruments of various kinds, 2,717 hangars, 379 squadron equipments, 317,353 items of aviator's clothing, 33,909 items of motor transport.

Of the above items the airplanes and spare parts cost $56,007,609.06; the engines and spare parts cost $61,809,618.40; and experimental purposes cost $1,426,493.38 (p. 555-g). This left a balance out of the original $640,000,000 appropriation of approximately $267,000,000 (pp. 3557, 3561).

The expenditures overseas up to June 30, 1919, amounted to $63,345,941.77. Of the oversea payments to May 31, 1919, $11,664,004.45 was for planes and spares; $10,320,510 was for engines and spares; $572,883.34 was for balloons and spares (553).

The sum appropriated to carry out a program of this extent was not out of line with the expense of conducting the war, and particularly of developing aircraft programs as experienced by ourselves and our allies during the war.

In the early part of the war, the English authorities cabled the United States, estimating that it would cost America $1,000,000,000 to place 1,000 flyers on the line. During the months of July, August, and September 1917, France spent over $50,000,000 per month, or at the rate of $600,000,000 per year on aviation for material alone (2910-XII-I).

The shipping problem as well as the lack of contact with service conditions greatly increased the expense and confused the aviation problem for America.

Trained pilots and service planes on the battle line are the ultimate purposes of an aviation program, but preceding that is the necessity of vast expenditures and tireless, skillful effort. Like every other effort, in aviation it is particularly true that the effort and expense of to-day do not bear fruit until to-morrow. No just nor patriotic criticism will condemn the effort of to-day because, fortunately, the preparation wisely made was not needed on the

morrow.

Prior to November 11, 1918, approximately $285,000,000 had been appropriated for naval aviation, of which appropriation $97,000,000 has been revoked on account of the unexpectedly early termination of the war, leaving a balance of approximately $188,000,000 of appropriations, of which over $143,000,000 had been expended (3551).

TRAINING FIELDS IN UNITED STATES

In December 1913 the Signal Corps announced the establishment of the first school for theoretical and practical instruction in aviation, to be located at San Diego. For about three years prior to that time, this location had been used as a training station by the Army and Navy and several civilians.

Among the first requirements of the aviation program for war was the establishment of additional training fields for flyers in the United States. The progress of this work is indicated by the number of fields, as follows: April 1917, 2; June, 4; July, 5; August, 6; September, 8; November, 9; December, 18; April 1918, 20; May, 25. Balloon schools: April 1917, 1; October, 2; December, 3; April

1918, 2.

Two photo schools were established in November 1917. Four were used from January 1918. The number of mechanics' schools were as follows: November 1917, 6; December, 7; January 1918, 15; February, 26; March, 28. Thirteen were closed in April, leaving 15 to continue from that time on.

During the early months of the war, only elementary training courses were given in the United States. Final courses in training service planes were necessarily completed in Europe (2910-XXVII). In final training in Europe, the flyers used the types of machines they were to operate on the front (2910-LXIV).

In August 1918, the American fields were giving advanced training courses.

TRAINING IN EUROPE

Early arrangements were made to train a limited number of men in the schools of our allies in Europe where there was room for that purpose. It was intended to give earlier preparation, early training while our fields were being prepared, and under the advantage of being near practical operations. The Allies were unable to accommodate the number expected and some of the men so sent to Europe did not receive training as soon as men who had remained in America for that purpose.

Later, American training flying fields were established in France. where final training could be given practically under battle conditions. The first of these American fields established was at Issoudun, which subsequently became the largest flying school in the world (2910-XXVIII).

Sixteen schools were established in France under American control. A total of 22 schools were used for American training purposes (2910-XCIX, 225). Lands for this purpose were leased. In some instances the school sites had buildings which had been used for these purposes by our allies, and they were taken over and the capacity increased. In all other cases the buildings and equipment had to be provided. Part of the lumber came from the United States. Some was purchased in France. Some was shipped from the Scandinavian Peninsula, and finally an amplified supply was furnished from the forests of France by our forestry troops (2910-XXVII).

Wagon roads were required to be constructed at all of these schools, and a railroad 7 miles in length was constructed to Issoudun.

The first instructors were procured from the French flying service. Subsequently the instructors were selected from among our best trained flyers.

Mechanical instructors were secured by putting Americans in the French factories to learn different types of construction and equipment. Some Americans were sent to French mechanical schools. Finally the mechanics were trained by qualified American mechanics at the schools (2910-XCIX).

Some elementary training was given our cadets in Europe, but the general practice was to give the elementary training in the United States, and the final training in Europe (225).

The total cost of establishing and maintaining Issoudun, the principal one of these schools, was $27,045,395.53 (XLVII).

Five hundred and forty-two men took training courses in the flying schools of England. Of this number 216 went from the English schools into the royal air forces; 96 went directly into the American forces. The 216 went into the British forces on account of the shortage of pilots on the British front. Most of them eventually entered the American service (2910-XXXV-1).

The schools in Italy were prepared to accommodate 500 Americans. Four hundred and six pilots graduated from the preliminary course, of whom 121 subsequently graduated from the Italian bombardment corps. Fifty-two took the Italian aero gunnery course. Sixty-five of the pilots saw service on the Italian front, and 60 were maintained at the Italian front. They represented over 20 per cent of the available piloting force on that front.

The total number of Americans graduated in Europe as fully trained pilots was 1,674 and 851 observers. Of these, 1,402 pilots and 769 observers went to the front (2910-XXXV-I).

GROUND SCHOOLS

On the 30th of April, 1917, the United States adopted the British ground school system in vogue in Canada. The purpose of these schools was to give prospective fliers an elementary training. It