| Description | Date | Identifier | |
| Table of values and a plot for the function sin 2(50 + θ). | 6th Jan 1921 | Box 61b \ 4 scan0005 | |
| Chart of estimated turns versus stiffness for various ring governor springs. | 6th Jan 1921 | Box 61b \ 4 scan0006 | |
| Ignition system for the Goshawk I engine, comparing various magneto and battery ignition options. | 15th Feb 1921 | Box 61b \ 4 scan0007 | |
| Lessons learned from U.S.A. electrical ignition equipment, comparing it to Remy and Bosch systems. | 16th Feb 1921 | Box 61b \ 4 scan0008 | |
| Comparative analysis of the American Bosch Battery Ignition system, focusing on its governor, contact maker, and coil. | 17th Feb 1921 | Box 61b \ 4 scan0009 | |
| Quality and cost of a distributor, comparing it to Bosch equipment and American manufacturing standards. | 1st Feb 1921 | Box 61b \ 4 scan0010 | |
| Manufacturing proprietary mouldings and comparing Bosch, Delco, and Remy ignition systems. | 16th Feb 1921 | Box 61b \ 4 scan0011 | |
| Comparing Bosch and Remy distributors and discussing manufacturing capabilities relative to the Americans. | 1st Feb 1921 | Box 61b \ 4 scan0012 | |
| On the U.S.A. Bosch battery ignition, detailing its components and supply terms from Bosch and Delco. | 24th Feb 1921 | Box 61b \ 4 scan0013 | |
| Decoded cablegram from Springfield requesting spark advance curve data for Bosch battery ignition, with a handwritten reply. | 28th Feb 1921 | Box 61b \ 4 scan0014 | |
| List of questions for Mr. Royce regarding battery ignition systems. | 3rd Mar 1921 | Box 61b \ 4 scan0015 | |
| Inspection notes on U.S.A. Bosch ignition equipment and its potential use on a Goshawk I engine. | 8th Mar 1921 | Box 61b \ 4 scan0016 | |
| Attaching a copy of a letter regarding American Bosch Battery Ignition. | 24th Mar 1921 | Box 61b \ 4 scan0017 | |
| Letter concerning the materials and performance of American Bosch battery ignition systems. | 4th Mar 1921 | Box 61b \ 4 scan0018 | |
| To Claude Johnson discussing issues and comparisons of various magneto and battery ignition distributor systems. | 4th Mar 1921 | Box 61b \ 4 scan0019 | |
| American Bosch Battery Ignition, enclosing other related correspondence. | 24th Mar 1921 | Box 61b \ 4 scan0020 | |
| Cover letter attaching a copy of another letter regarding American Bosch Battery Ignition. | 23th Mar 1921 | Box 61b \ 4 scan0021 | |
| Letter discussing technical issues with the American Bosch Battery Ignition system, specifically the governor and contact maker. | 7th Mar 1921 | Box 61b \ 4 scan0022 | |
| Technical memorandum discussing the features, materials, and cost of American Bosch ignition coils and distributors. | 7th Mar 1921 | Box 61b \ 4 scan0023 | |
| Bakelite molding outfit at the Delco factory, pricing from the Bosch company, and the material of Delco distributor tracks. | 7th Mar 1921 | Box 61b \ 4 scan0024 | |
| Extract from a report on electrical matters, detailing a visit and discussions about battery ignition systems. | 19th Mar 1921 | Box 61b \ 4 scan0025 | |
| The American Bosch Induction Coil and the use of Bakelite and other insulating materials in distributors. | 5th Apr 1921 | Box 61b \ 4 scan0026 | |
| Page stating that Ebonite, or 'Hard rubber', is only used for experimental work. | 15th Apr 1921 | Box 61b \ 4 scan0027 | |
| Requesting the return of a U.S.A. Bosch Battery Ignition system. | 15th Apr 1921 | Box 61b \ 4 scan0028 | |
| Confirming the dispatch of a Ni-Fe battery and a delay in sending the Bosch Battery Ignition. | 28th Apr 1921 | Box 61b \ 4 scan0029 | |
| From Mr. Olley discussing and comparing various ignition systems, including Delco, Bosch, and general American electrical equipment. | 1st Jun 1921 | Box 61b \ 4 scan0030 | |
| Report discussing various ignition systems, comparing American and English manufacturers and performance. | 16th May 1921 | Box 61b \ 4 scan0031 | |
| Extract concerning the performance and fitting of an American Bosch battery ignition on Chassis 4 EX. | 10th Dec 1930 | Box 61b \ 4 scan0032 | |
| Letter from the American branch regarding payment for a magneto and battery system furnished by the American Bosch Magneto Corporation. | 20th Jun 1921 | Box 61b \ 4 scan0033 | |
| The petrol tank for the '4 EX' vehicle, discussing modifications, weight, ventilation, and filler design. | 21th Nov 1921 | Box 61b \ 4 scan0034 | |
| Communication discussing carburettor fittings and petrol level indicators, emphasizing quality and reliability over cost. | 21th Jun 1921 | Box 61b \ 4 scan0035 | |
| Application and deficiencies of a Bosch battery ignition system. | 21th Jun 1921 | Box 61b \ 4 scan0036 | |
| Technical review of a driving spindle, condenser, oil in the apparatus, and a low tension contact maker. | 1st Jun 1921 | Box 61b \ 4 scan0037 | |
| Design and placement of ignition components including the governor, coil, ballast resistance, and spares. | 21th Jun 1921 | Box 61b \ 4 scan0038 | |
| Selection of magneto, battery ignition, and switchbox components from suppliers like Bosch and Westinghouse. | 21th Jun 1921 | Box 61b \ 4 scan0039 | |
| To the US branch regarding the quality of supplier parts and specifications for switchboxes and other fittings. | 21th Jun 1921 | Box 61b \ 4 scan0040 | |
| Sketch of a spigot for an American Bosch battery ignition on a 40/50 chassis throttle governor casing. | 23th Jun 1921 | Box 61b \ 4 scan0041 | |
| Recommendation to incorporate a modified spigot for battery ignition on 40/50 cars made at Derby. | 25th Jun 1921 | Box 61b \ 4 scan0042 | |
| The fitting and testing of the U.S.A. Bosch Battery Ignition system for the 40/50 chassis. | 1st Jul 1921 | Box 61b \ 4 scan0043 | |
| Battery ignition weaknesses and ignition timing specifications for 40/50 chassis and U.S.A. Bosch Ignition. | 6th Jul 1921 | Box 61b \ 4 scan0044 | |
| Table of ignition timing settings against engine revolutions, with notes on detonation and governor performance. | 6th Jul 1921 | Box 61b \ 4 scan0045 | |
| Extract discussing U.S.A. complaints regarding battery ignition systems and the reliability of tungsten versus platinum-iridium contacts. | 12th Jul 1921 | Box 61b \ 4 scan0046 | |
| Experimental work and measurements on a U.S.A. Bosch battery ignition system and its components. | 5th Sep 1921 | Box 61b \ 4 scan0047 | |
| Continued discussion on ignition systems, condensers, and the integration of a new Bosch battery ignition. | 5th Sep 1921 | Box 61b \ 4 scan0048 | |
| Letter concerning quotes, delivery, and components for American Bosch Battery Ignition sets. | 18th Jul 1921 | Box 61b \ 4 scan0049 | |
| Dual ignition set, coil specifications, and a mounting diagram. | 18th Jul 1921 | Box 61b \ 4 scan0050 | |
| The ignition system's coil, condenser, and contact breaker, comparing Bosch and American components. | 18th Jul 1921 | Box 61b \ 4 scan0051 | |
| The performance, maintenance, and costs of ignition system components like rockers, contact breakers, and distributors. | 18th Jul 1921 | Box 61b \ 4 scan0052 | |
| Distributor designs and modifications to an ignition system, continued on sheet #5. | 19th Jul 1921 | Box 61b \ 4 scan0053 | |
| The starting procedure for an engine fitted with a U.S.A. Bosch battery ignition. | 19th Jul 1921 | Box 61b \ 4 scan0054 | |
| Extract regarding permission for the U.S.A. to adopt Bosch and Bijur components for ignition, starting motor, and dynamo. | 22th Jul 1921 | Box 61b \ 4 scan0055 | |
| Letter discussing the supply and suitability of ignition parts, generators, and starting motors from Delco. | 3rd Aug 1921 | Box 61b \ 4 scan0056 | |
| Issues with American Bosch dual ignition sets and considering a Delco replacement. | 3rd Aug 1920 | Box 61b \ 4 scan0057 | |
| Letter to the Managing Director outlining reasons against approaching the American Bosch Co. to produce a special ignition coil. | 4th Aug 1921 | Box 61b \ 4 scan0058 | |
| Coil mounting and the durability of platinum iridium points in contact breakers. | 6th Jul 1921 | Box 61b \ 4 scan0059 | |
| Technical specifications and test results for a USA Bosch Battery Ignition Coil. | 5th Aug 1921 | Box 61b \ 4 scan0060 | |
| Calculations for electrical impedance, resistance, and inductance of a secondary component. | 6th Nov 1918 | Box 61b \ 4 scan0061 | |
| Test results and calculations for a ballast and a condenser. | 6th Nov 1918 | Box 61b \ 4 scan0062 | |
| The performance of a condenser, comparing it to the standard RR model. | 6th Nov 1918 | Box 61b \ 4 scan0063 | |
| The initial testing and measurement of a U.S.A. Bosch battery ignition system. | 5th Sep 1921 | Box 61b \ 4 scan0064 | |
| Condenser connections and various battery ignition systems, including Goshawk II and U.S.A. Bosch. | 5th Sep 1921 | Box 61b \ 4 scan0065 | |
| On testing U.S.A. Bosch condensers for battery ignition systems and recommending further trials for the Goshawk II. | 16th Sep 1921 | Box 61b \ 4 scan0066 | |
| On the successful testing and adoption of Bakelite-Micarta bushes to replace fibre bushes in magnetos. | 16th Sep 1921 | Box 61b \ 4 scan0067 | |
| Recommendation to fit Bakelite-micarta bushes to magnetos and source them from Springfield. | 16th Sep 1921 | Box 61b \ 4 scan0068 | |
| Extract discussing the high capacity and space efficiency of U.S.A. Bosch battery ignition condensers. | 27th Sep 1921 | Box 61b \ 4 scan0069 | |
| Test results of standard and U.S.A. Bosch ignition coils. | 25th Oct 1921 | Box 61b \ 4 scan0070 | |
| Letter from Rolls-Royce of America concerning battery ignition condenser tests and insulation breakdown. | 21th Nov 1921 | Box 61b \ 4 scan0071 | |
| Letter from American Bosch Magneto Corporation comparing testing procedures for battery ignition condensers. | 6th Sep 1921 | Box 61b \ 4 scan0072 | |
| Letter from American Bosch Magneto Corporation discussing condenser leakage resistance, capacity, and manufacturing processes. | 13th Dec 1921 | Box 61b \ 4 scan0073 | |
| Query regarding the status of an order for three sets of U.S.A. Bosch battery ignition systems, with supporting extracts. | 13th Dec 1921 | Box 61b \ 4 scan0074 | |
| Request for a performance report on an American Bosch Ignition system on the 4-EX. | 1st Mar 1922 | Box 61b \ 4 scan0075 | |
| Technical evaluation and comparison of the American Bosch battery ignition system. | 16th Feb 1921 | Box 61b \ 4 scan0076 | |
| Analysis of a distributor, comparing its quality, manufacturing, and cost against Bosch equipment. | 16th Feb 1921 | Box 61b \ 4 scan0077 | |
| In-house manufacturing of Bakelite moldings and comparing Bosch, Delco, and Remy ignition systems. | 16th Feb 1921 | Box 61b \ 4 scan0078 | |
| Continued discussion on faults with Delco ignition distributors and manufacturing comparisons. | 16th Feb 1921 | Box 61b \ 4 scan0079 | |
| Features, materials, and supply conditions of a U.S.A. Bosch Battery Ignition system. | 24th Feb 1921 | Box 61b \ 4 scan0080 | |
| Technical memorandum discussing the 'Goshawk 11' battery ignition and comparing various distributor designs. | 24th Feb 1921 | Box 61b \ 4 scan0081 | |
| Test results of standard and U.S.A. Bosch ignition coils. | 15th Sep 1922 | Box 61b \ 4 scan0082 | |
| Technical memorandum regarding phenomena found in the Goshawk and other battery ignition systems. | 13th Nov 1922 | Box 61b \ 4 scan0083 | |
| Proposing tests for condenser materials and discussing ignition coil construction and failures. | 13th Nov 1922 | Box 61b \ 4 scan0084 | |
| Letter discussing the testing, comparison and potential standardisation of stabalite and mouldensite ignition coils for the Goshawk engine. | 13th Nov 1922 | Box 61b \ 4 scan0085 | |
| Procedure for standardizing the American chassis to match the English chassis, including specific critiques of the Bosch battery ignition system. | 27th Dec 1922 | Box 61b \ 4 scan0086 | |
| Engine improvements, focusing on ignition, heated throttles, and induction systems for cold weather performance. | 27th Dec 1922 | Box 61b \ 4 scan0087 | |
| Continued note on the main throttle valve, identifying it as a patentable feature for safety reasons. | 20th Sep 1923 | Box 61b \ 4 scan0088 | |
| Expressing dissatisfaction with the electrical equipment for the U.S.A. Springfield chassis, questioning its reliability and considering alternatives. | 20th Sep 1923 | Box 61b \ 4 scan0089 | |
| Extract of a communication regarding the reliability of American Bosch ignition systems on Springfield electrical equipment. | 8th Oct 1923 | Box 61b \ 4 scan0090 | |
| Alternative metals for H.T. distributors and issues with insulation tracking compared to a Bosch part. | 15th Sep 1925 | Box 61b \ 4 scan0091 | |
| From 'R.' to 'EFC.' posing several questions regarding electrical experiments, particularly comparing coils and contact points. | 16th Aug 1926 | Box 61b \ 4 scan0092 | |
| Ignition contact points, comparing materials, and arranging a meeting. | 20th Aug 1926 | Box 61b \ 4 scan0093 | |
| Comparative bench tests of ignition contact points made from Platinum, English tungsten, and U.S.A. tungsten. | 20th Aug 1926 | Box 61b \ 4 scan0094 | |
| Temperature-current tests comparing a leaky American Bosch condenser with the company's own manufactured condensers. | 20th Aug 1926 | Box 61b \ 4 scan0095 | |
| Inter-office correspondence detailing the components of two special clockwise distributor heads being shipped to Derby. | 7th Sep 1926 | Box 61b \ 4 scan0096 | |
| Page 2 of a letter listing various parts with quantities and descriptions. | 7th Sep 1926 | Box 61b \ 4 scan0097 | |
| Letter concerning the dispatch of a complete double ignition head and coils for a Phantom engine. | 17th Sep 1926 | Box 61b \ 4 scan0098 | |
| Receipt and planned testing of American Bosch battery ignition equipment. | 1st Oct 1926 | Box 61b \ 4 scan0099 | |
| Preliminary examination of an American Bosch ignition coil and distributor fitted to a chassis in America. | 25th Oct 1926 | Box 61b \ 4 scan0100 | |
| Plan to test an American battery ignition unit on a Phantom, noting its successful use in the USA. | 8th Nov 1926 | Box 61b \ 4 scan0101 | |
| Comparison of an American Bosch ignition coil's resistance and inductance against standard company coils. | 8th Nov 1926 | Box 61b \ 4 scan0102 | |
| Analysis of the American Bosch Ignition Coil Type TC.30, detailing its construction and features. | 5th Nov 1926 | Box 61b \ 4 scan0103 | |
| Sending a photostat of a Delco coil for comparison with an American Bosch coil. | 11th Nov 1926 | Box 61b \ 4 scan0104 | |
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