Physical Description: 1. Hallett Correspondence, U.S. Signal Corps (1915-1918) 2. Hallett Correspondence, Army Air Corps (1918-1921) 3. Hallett Correspondence, General Motors (1931-1955) 4. Hallett Correspondence, Consolidated Aircraft Corporation (1942-1944) Includes letters to and from Reuben H. Fleet, and between Hallett and outside individuals and companies. Topics are quite far ranging and innovative, including the cycle-weld process, spark plug and ignition harness design, airplane and helicopter engines, including rotary and small jet engines, the Crosley concept automobile, development of water supply wells at Consolidated, developing a water recovery system, aerial refueling concepts, development of a small helicopter, the Cylcopter concept, air freighter troop container, transporting gasoline from Los Angeles, converting the B-24 to a two engine cargo plane, airport runway lighting concept, solar evaporation of waste fluids, invention agreements, rotating wing aircraft, transporting gasoline to China, liquid oxygen and liquid hydrogen as fuel, candidate air tanker cargoes, fog dissipation concept, and the Burnelli planes. 5. Hallett Correspondence, Miscellaneous (1914-1981) 6. Draft Board Records (1917) 7. George Hallett Last Will and Testament (1938) 8. Arizona Tungsten Ore Mining Correspondence, Claims and Records (1938-1940) 9. Correspondence from J.J. Smith Documenting 138th Aero Squadron History (1958) 10. Correspondence with Peter Beck Concerning OX Engine (1959) Technical Reports and Special Studies 11. Airplane Motors, A Practical Course of Instruction in the Principles, Overhauling, and Care of Airplane Motors, George E.A. Hallett, copyrighted 1917, printed 1918, Washington, Government Printing Office 12. Airplane Motors Instruction Book Notes (circa 1918) 13. Notes on Starting Curtiss V8 60 Horsepower Engine 14. Notes and Rules for Pilots (circa 1918) 15. Inspection of Aeroplanes before Flights (circa 1918) 16. Principle Characteristics of Foremost Engines of 1918 17. Martin Club Address (Glenn L. Martin Company, circa 1918) 18. Digest of Development of Aviation Engines, 1914 to 1919 19. Outline of Policy for the Power Plant Department at McCook Field (1919) 20. Probable Future Development of Aeronautics in War and Commerce Including Both Heavier-than-Air and Lighter-than-Air Branches (1920) 21. Specification for Air Cooled Engine for Pursuit Type Airplane (U.S. Army - 1920) 22. Development of Efficient Air - Cooled Cylinders (1919-1923) 23. Hallett Valve Design Sketches (1920-1921) 24. Effect on Cylinder Performance at Variations in Stroke Length and Compression Ratio, McCook Field (circa 1924) 25. Notes of a Proposed Engine of the Engineering Division, Wright Field (1929) 26. Desirable Engine Characteristics (1929) 27. Wright Cyclone Engine Performance (circa 1930) 28. Bristol Phoenix Diesel Engine Performance (circa 1930) 29. Proposed Eight Cylinder Engine Sketch (circa 1930) 30. Soap Bubble Formulae (circa 1930)

Physical Description: 31. General Motors Valve Designs (circa 1932) 32. Two Cycle Engine Development, General Motors (1932) 33. Two Cycle Engine Characteristics (1932-1937) 34. Balance Characteristics, Crankshaft and Cylinder Arrangements of Two Cycle Engines having 3 to 16 Cylinders (1932) 35. Mechanical and Chemical Aspects of Exhaust Odor and Idle on Single Cylinder Two Cycle Engine (1933) 36. Investigation of a Design for 12 Cylinder Opposed Engine (1935) 37. Aircraft U-124 Engine Program (1935) 38. Aircraft Two Cycle “U” Type Single Cylinder Engine Development (1935) 39. Excerpts from “Man, The Unknown,” by A. Carrel (1935) 40. Notes on Airplane Engine Conference (19 April 1935) 41. Stroboscopic Analysis of Two-Cycle Combustion (1936) 42. Gas Injection Diesel Study (1936) 43. Gas Engine Refrigeration Unit Development (1936) 44. Progress on Study of Exhaust Odor Formation in Two Cycle Engine (1936) 45. Engine Exhaust Odor Measurement (1936) 46. Desaxe “U” Type Cylinder Design Data (1936) 47. Proposed Four Cylinder Radial Engine, 400 BHP @ 2250 RPM (1936) 48. Study of Oil Flow in Connecting Rods for Piston Cooling (1936) 49. Universal Test Engine Design (Undated) 50. V-1710 C1/C2/C3 Engine Weight Analysis (Circa 1936) 51. Material Selection - Allison 1710 Engine Cylinder Head (1937) 52. Hydrovanes – Useful Adaptations and Improvements (1937) 53. Tests on Exhaust Gas Dilution at Full Load in Two Cycle Engine (1937) 54. Two Cycle Engine Fuel Injection Pump (1938) 55. Hallett Article - Early Steps toward Air Power (1941) 56. Harper Injection Aircraft Engine (1942) 57. Development of Large Airplane Engine (1942) 58. Proposed Large Airplane Engine (1943) 59. Airplane Engines of Higher Horsepower and Lower Specific Weight (1943) 60. Problems Connected with Two-Line Engine (1943) 61. Suggested Notes for Aircraft Ground Observers (1952) 62. Aircraft Engine Performance Relationships (circa 1918-1936) 63. Measurement of Plain Bearing Material Score Resistance (1979) 64. General Engineering Relationships and Conversion Factors Interviews, Recollections and Biographical Information 65. Notes from George Hallett Diaries (1912) 66. Personal Chronology of Aeronautics Activities, 1908-1922 (1935) 67. “Odds And Ends,” Early Planes and Engines Experiences and Recollections – Undated 68. George E.A. Hallett Chronological Observations (Undated) 69. Discussion of George Hallett Patents (1956) 70. Personal Recollections (Early Engine Development, History, Experiences, Problems, Testing Focus - circa 1911-1920) - Transcribed from circa 1957

Physical Description: 71. Powered Aircraft Flown by Major G.E.A. Hallett - Chronological List (1958) 72. George Hallett, Aeroplane Mechanician and Early Bird - Planned Article or Book, as Related by Hallett to Bruce Reynolds (1958) 73. George Hallett, Aeroplane Mechanician and Early Bird – Part II (1958) 74. George Hallett Biographical Transcription of post-1917 Experiences (1958) 75. Electro-Motive Study: Interview with George E.A. Hallett, 1959 (Recollections of Early General Motors Diesel Engine Development) 76. Transcript - Interview with George E.A. Hallett, 5 April 1960 (San Diego Historical Society - 21 pages) 77. Tribute to Sam Heron by Harold E. Morehouse (1964) 78. San Diego Aerospace Museum Historical Committee (1964) 79. The Wanamaker - Curtiss 1914 Transatlantic Project Recollections (1968) 80. Biographical Notes (1956-1958) 81. Hallett Tribute - San Diego Aerospace Museum Countdown (Fall, 1967) 82. The Early Birds of Aviation Record (1975) 83. McCook Field Questionnaire (Smithsonian) 84. George Hallett Historical Information - Early Aviators (2010 Internet Search) Articles 85. Miscellaneous Published Information and Newspaper Articles (1935-1982) Photographs 86. Aero Club and Curtiss Biplane, U.S. Aviation Field, San Diego (1911) 87. Curtiss Students at North Island in 1911 Lt. Kelley, Lt. Beck, Glenn H. Curtiss, C.C. Witmer, Lt. Walker and Lt. Ellyson 88. Curtiss students at North Island in 1911 (a second, different group photograph) John D. Cooper, H.C. Robinson, Lt. Beck, Shackelford, Lt. Walker, C.C. Witmer, Glenn H. Curtiss, Lt. Ellyson, Lt. Henry, Lt. Kelley and “Slim” Purington 89. Informal Group Picture at North Island in 1911 Greer, Cooper, Beck, Mrs. Beck, Carl Adams, Shackelford, Walker, Ellysen, Witmer, and Robinson. 90. Glenn Curtiss and first “Triad” Amphibian (North Island – 1911) 91. Lieutenant L.G. Ellyson in A-1 Elevated Platform Launch (1911) 92. Ellysen and Witmer at North Island (Swim Suits - 1911) 93. C.C. Witmer and George Hallett, Exhibition Curtiss Hydro, DePere Wisconsin (1911) 94. Byron “Death Valley Slim” Purington - Mechanic - North Island (1912) 95. Unidentified Group (likely at North Island circa 1912) 96. A-2 on Catapult (Washington Navy Yard - 1912) 97. Curtiss Flying Boat Delivered to German Baltic Fleet (1913) 98. Walker, Ellyson and Ely, Coronado Polo Grounds (1911) 99. First Curtiss Model “J” Fitted with Pontoon at Hammondsport, NY (1914) 100. First Curtiss Model “J,” Hammondsport, NY (1914) 101. George Hallett and Curtiss Model N (North Island - 1914) 102. Lt. J.C. Porte, George Hallett and Glenn H. Curtiss with “America” (1914) 103. Army Competition Selection Aircraft - North Island (1914/1915) In October 1914, five American aircraft manufacturers proposed higher powered, newly designed airplanes to compete for the Army’s use at North Island Curtiss Model N: Curtiss OXX Engine Martin: Hall Scott Engine Schmidt Biplane: Le Rhone Engine Burgess Dunne: Salmson Engine Wright “Tin Cow” - Austria Daimler Engine 104. Curtiss Model “J” (1915) 105. Engineering Class at North Island, George Hallett, Instructor (1915) - Two Group Photographs 106. Second Officer Class, Aviation School, Signal Corps, North Island (1916) Lyon, Newbold, Kruss, Stockton, Horigan, Walton, Colonel W.L. Kenly, O’Malley (civilian) and Hallett (civilian) 107. Enlisted Mechanics, Mechanics School, North Island (1916) Curtiss, Doty, Johnson, Fordington, McKeane, Hardy, O’Malley, Hallett, Hammond, Holte, Pickup and Montijo 108. Class of Officers at North Island - Hallett in Charge (1917) 109. Mechanics School at North Island - Second Building (1917) 110. Major Oscar Brindley in Wright Airplane (c. 1918) 111. Fred A. Hoover (circa 1918-1921) 112. Major George E.A. Hallett (1919, circa 1920s, circa 1930s, 1963, 1965 and 1969) 113. McCook Field, Engineering Division, W-1 Engine (1920) 114. Dr. George De Bothezat (Romanian/Russian helicopter pioneer), Frederick Handley Page, Colonel Thurman H. Bane and George E.A. Hallett at McCook Field (1921) 115. General Electric Engine Supercharger Photo Series at McCook Field (1921) List of photos in Hallett General Electric supercharger collection; first Glenn L. Martin bomber with General Electric supercharger; close-up of Martin bomber w/supercharger; supercharged Packard 12 engine in DH-4; G.E. supercharger with shrouds, and without shrouds; McCook Field Intercooler 116. Liberty engine in DH-4 with G.E. Supercharger on Army Experimental Airplane, set Altitude Record (1928) 117. Unidentified Artist Rendering - Small Bat-like Design (identified as Pattingan or Pattengar on reverse) - likely mid-1930s Concept 118. Reproduction, Henry Ford and Orville Wright, Five Others Including Edsel Ford (circa late 1930s to early 1940s) 119. George Hallett with Two Ladies (circa 1970-1980) 120. Cypress View Memorial for Mr. and Mrs. Hallett 121. Unidentified Observers/Photographers (circa 1914-1918) 122. Lincoln Beachey Curtiss Pusher Replica (circa early 1970s)

Physical Description: Invention Development Records, Patents, Engineering Sketches and Drawings 123. Invention Development Records These records deal with engine design improvements, inventions, or proposed inventions, for the most part dating from when Hallett was employed at the General Motors Research Laboratory. Engine design improvements include, but are not limited to: poppet type injection valve, spark plug cooling, carburetor heater valve, carburetor heating coil, rocker and bevel cone mechanism, engine injection valve, variable inlet and exhaust system, Packard valve gear, flared port holes in steel cylinder liners, light car engine with fluid fly wheel, connecting rod pin, crank shaft pin, valve gear lubrication, valve seat cooling, connecting rod bearings, two cycle engine exhaust heater, combustion chamber arrangement, intake/exhaust/air valve timing, copper lined cast iron guide, localized charge in two cycle engine, exhaust collector and air supply for single valve engines, fluid cooled cylinder with radiating fins, two cylinder engine connecting rods, fuel feed nozzles, and supercharged two cycle engine. 125. Patents (Not All Attributable to George Hallett) No. 981,216 (1911), Apparatus for Generating Steam or Other Vapors No. 981,217 (1911), Apparatus for Generating Steam or Other Vapors No. 981,218 (1911), Apparatus for Generating Steam No. 988,374 (1911), Internal Combustion Engine No. 1,008,188 (1911), Internal Combustion Engine No. 1,139,898 (1915), Internal Combustion Engine No. 1,319,789 (1919), Carburetor No. 1,339,218 (1920), Carburetor No. 1,359,828 (1920), Carburetor No. 1,496,673 (1924), Gas Mixers No. 1,755,989 (1930), Brake Control; Re-issue 18,997 (1933) No. 1,757,425 (1930), Hydraulic Valve Mechanism No. 1, 819,715 (1931), Eccentric Balance Driving Gear No. 1,872,141 (1932), Hydraulic Valve Operating Mechanism No. 1,872,279 (1932), Lubricating System No. 1,874,446 (1932), Ported Cylinder Construction No. 1,897,934 (1933), Rear Wheel Arrangement for Motor Buses No. 1,898,459 (1933), Crank Shaft Balancing No. 1,898,460 (1933), Two-Cycle Engine No. 1,929,108 (1933), Oil Pressure Regulator No. 1,930,261 (1933), Slack Adjuster No. 1,930,553 (1933), Hydraulic Drive Gear No. 1,930,554 (1933), Hydraulic Valve Mechanism No. 1,931,476 (1933), Hydraulic Valve Lash Adjusting Mechanism No. 1,936,667 (1933), Hydraulic Drive Mechanism No. 1,937,932 (1933), Rocker Arm Assembly No. 1,950,970 (1934), Two Cycle Engine No. 1,984,013 (1934), Two Stroke Cycle Engine No. 1,996,807 (1935), Valve Gear for Operating Dual Valves No. 1,997,279 (1935), Piston Driving Mechanism No. 2,001,858 (1935), Lubricating System with Initial Splash No. 2,014,932 (1935), Roots Blower No. 2,067,757 (1937), Engine Blower Control No. 2,067,984 (1937), Two-Cycle Engine Load Control No. 2,133,510 (1938), U-Type Two-Cycle Engine Engineering Drawings 126. Manly Hydraulic Drive (1923) 127. Frigidaire Division (Blueprint), No. EC-25114, Constant Compression Engine (1936) 128. Awards and Certificates 129. Diaries, Memoranda and Address Books 1911 1911-1912 1911-1913 1912-1914 1913 (2) 1914 (2) Curtiss Model E Hydro Notes

Physical Description: General Motors Corporation (Blueprints) No. L-1809, Diesel Engine Fuel Injector (1929) No. L-1874, Fuel Injection Pump Layout, Sheets 3 and 4 of 4 Sheets (1930) No. L-2411, Cylinder to Head Flange (1934) No. L-2622, Two Cycle Engine, 2.14 Cu. In., Opposed Cylinders (1935) No. L-2636, Radial Accessory Drive, Sheets 1 and 2 (1935) No. L-2637, Four Cylinder Radial, Sheets 2 and 4 of 4 Sheets (1936) No. L-2638, Rocker Engine, Sheet 1 of 4 Sheets (1935) No. L-2640, Piston Compressor for Rocker Engine (1936) No. L-2669, Engine, 2.2 Cubic Inch Displacement (1936) No. 75790-D, Injection Nozzle Assembly (1931) No. 78651-D, Cylinder Assembly No. 79817-C, Piston, Strut Type, Design No. 2 (1934) No. 79844-C, Piston, Steel, Hydrogen Brazed, Design No. 4 (1934) No. 6098827-D, Cylinder Assembly, Desaxe Type (1935) No. 6099328-C, Port Spray Assembly (1936) No. 6099940-C, Combustion Chamber, Shock Absorber (1936) No. 6099462-C, Rotary Blower (1936) No. 6100265-A, Cushion Seat for Valve (1937) No. 6100288-R, Cylinder Block, Sheets 1-5, of 5 Sheets (1937)