This document summarizes recent (July-September 1924) research and development activities relevant to the Air Service. Article listing: Aircraft development: Airplanes: Observation types: The Loening Amphibian; Atlantic Aircraft gets contract for DH-4M2s; Bombardment types: Reconditioning the Barling Bomber; Torsion tests on the new Curtiss bomber; Pursuit types: New radiator and side supercharger for Curtiss pursuit; Boeing pursuit undergoes extensive flight tests; Training types: Specifications for new training types prepared; Miscellaneous projects: Douglas builds modified World Cruiser for overseas duty; Contract for new transports awarded to Douglas; Tests of 'Oleo' shock-absorber struts; Airships and balloons: RS-1 airship nears completion; Test of transmission for RS-1 airship; Deficiencies in TC envelopes--Stoppage of fuel lines; Wind screens prove effective with small airships; Armament: New A-3 and G-4 bomb racks under test; Marazzi (Italian) gun mount under investigation; Experiments with bullet-proof glass; Browning guns on wings of DH-4B; A. S. gun camera superior to French 'O.P.L'; Equipment: Smith airspeed recorder (British); New A-2 airplane landing light; The induction compass--Its principle and operation; New Eclipse starter shows marked superiority; Tests on new aircraft storage batteries; English alkali battery inferior to A.S. lead-acid type; Portable photographic developing machine; Power plants: Development of Curtiss D-12 engine; Fuel tests with Curtiss D-12 engine; New ignition diagram for Liberty; Liberty engine development; Liberty engine parts test; New Packard 'IA-1500' and 'IA-2500' engines; Side superchargers purchased; Tests of Wright 'T-3" engine; Research and development--Resume of Engineering Division serial reports: Airplane section Probability of forced landings with multi-engined airplanes--Serial no. 2366; Altitude horsepower of supercharged Liberty from propeller characteristics--Serial no. 2386; Preliminary study of theoretical loads on wings--Serial no. 2388; Effect of wing ribs on buckling action of spars--Serial no. 2391; Design data for new ambulance airplane, Model A-1; Structural members under combined axial and transverse loads--Serial no. 2400; Static tests; Wind tunnel tests; Armament section: Effect of gunfire on wing surface radiators; Equipment section: Instrument for detecting gasoline vapors--Serial no. 2357; Time and speed computer--Serial no. 2381; Test of electric farm lighting plants for searchlight beacon operation--Serial no. 2393; Flying section: Performance of Consolidated training model TW-3--Serial no. 2356; Limiting load and ceiling of airplanes--Serial no. 2360; Free flight characteristics of airplanes with different propellers--Serial no. 2371; Performance of Boeing Pursuit with Curtiss high compression engine--Serial no. 2371; Material section: Airplane lacing cord--Serial no. 2291; Redesigned airplane wheel, size 28x4--Serial no. 2313; Bleaching and semi-bleaching balloon fabric--Serial no. 2334; Mechanical properties of cast magnesium base alloys--Serial no. 2335; Priming coats for duralumin--Serial no. 2341; Power plant section: Description of power plant laboratory at McCook Field (revised)--Serial no. 1987; Performance of Wright Type 4 engine, giving modifications of Model H--Serial no. 2265; Investigation of balance of sixteen cylinder Type X engine--Serial no. 2281; Flight tests of Mosler and Brewster-Goldsmith spark plugs--Serial no. 2293; Multi-cylinder engines with cylinders six-in-line--Serial no. 2320; Cooling flight tests of Curtiss pursuit--Serial no. 2327; Investigation of materials: Army and Navy Air Services standardize specifications to aid industry; Efficiency of small steel springs; Madsenall process for nickel-plating streamline wire; New books and documents--Reference data on aeronautical development and engineering in the United States and other countries added to the technical files of the Air Service, Engineering Division--International activities: [General]; France; United States; Records, etc; Aerial navigation: Airways and airdromes; Meteorology; Regulation; Research: [general]; Design, computations and characteristics; Aircraft; Armament; Equipment; Fuels and lubricants; Materials: Aluminum and alloys; Brass and bronze; Fabric; Molybdenum; Nickel; Rubber; Steel; Wood; Foundry methods and testing of materials; Parachutes; Propellers; Power plants.