| Description | Date | Identifier | |
| 'Silectron' cigar lighter, its construction, and performance. | 7th Dec 1920 | Box 50 \ 2 Scan003 | |
| Letter clarifying the specifications and intended use of a Car Heater, including its wattage and power source. | 8th Dec 1920 | Box 50 \ 2 Scan004 | |
| Opinions and an anecdote about the Quain 'Silectron' Cigar Lighter. | 13th Dec 1920 | Box 50 \ 2 Scan005 | |
| Instructions and test results for a 'Radamax' Plug Lester. | 27th Nov 1920 | Box 50 \ 2 Scan006 | |
| Instructions detailing the results of sparking tests with different gap settings. | 24th Jan 1919 | Box 50 \ 2 Scan007 | |
| The 'Radamax' plug tester, explaining its function and requesting a trial on experimental cars. | 7th Dec 1920 | Box 50 \ 2 Scan008 | |
| Internal request to order a 'Radamax' plug tester from Messrs. Smith & Sons for experimental testing. | 23th Dec 1920 | Box 50 \ 2 Scan009 | |
| Instruction memo regarding a report on a Radamax Plug Tester. | 23th Dec 1920 | Box 50 \ 2 Scan010 | |
| Radamax plug tester for use on an experimental car. | 4th Jan 1921 | Box 50 \ 2 Scan011 | |
| Reviewing the functionality and usability of a Radamac plug tester. | 6th Jan 1921 | Box 50 \ 2 Scan012 | |
| The 'Radamax' Plug Tester, an instrument for distinguishing between good and faulty sparking plugs. | 7th Jan 1921 | Box 50 \ 2 Scan013 | |
| Continued report on spark plug testing, discussing spark characteristics and experiments with a 'Radamax' plug tester. | 1st Jan 1921 | Box 50 \ 2 Scan014 | |
| The performance, functionality, and pricing of the 'Radamax' plug tester. | 7th Jan 1921 | Box 50 \ 2 Scan015 | |
| The return of a damaged Radamax Plug Tester for inspection. | 10th Jan 1931 | Box 50 \ 2 Scan016 | |
| Return of a faulty 'Radamax' plug tester due to a fitting issue with its box. | 10th Jan 1921 | Box 50 \ 2 Scan017 | |
| Instruction note regarding a Radamax Plug Tester returned from repair. | 25th Jan 1921 | Box 50 \ 2 Scan018 | |
| The receipt and proposed testing of 'Mercury' brand sparking plugs. | 22th Oct 1920 | Box 50 \ 2 Scan019 | |
| Unsuitability of Mercury sparking plugs due to their mica-type construction. | 16th Nov 1920 | Box 50 \ 2 Scan020 | |
| Correspondence regarding the testing of Mercury Sparking Plugs with different insulator types. | 22th Nov 1920 | Box 50 \ 2 Scan021 | |
| Request for a further supply of one dozen type GB.3 Mercury sparking plugs with porcelain insulation. | 14th Jan 1921 | Box 50 \ 2 Scan022 | |
| Quotation for 1,000 sparking plugs from Mercury Sparking Plug Co. | 7th Feb 1921 | Box 50 \ 2 Scan023 | |
| Methodology for a series of tests on various sparking plugs. | 9th Feb 1921 | Box 50 \ 2 Scan024 | |
| Test report comparing the performance and durability of various types of spark plugs. | 9th Feb 1921 | Box 50 \ 2 Scan025 | |
| Report comparing the performance and cost of Mercury, Champion, and Bethlehem spark plugs. | 9th Feb 1921 | Box 50 \ 2 Scan026 | |
| Order for two dozen Mercury sparking plugs, type GB.3. | 11th Feb 1921 | Box 50 \ 2 Scan027 | |
| Requesting costs be added to standardisation sheets for Eagle water outlet connections and Mercury sparking plugs. | 15th Feb 1921 | Box 50 \ 2 Scan028 | |
| Requesting review of standardisation sheets for Mercury CR3 sparking plugs. | 15th Feb 1921 | Box 50 \ 2 Scan029 | |
| Comparison of Mercury, Champion, and Lodge spark plugs, with notes on post-war supply issues. | 16th Feb 1921 | Box 50 \ 2 Scan030 | |
| Conclusion recommending the standardization of Champion and Mercury parts for U.S.A. and English made cars respectively. | 16th Aug 1921 | Box 50 \ 2 Scan031 | |
| Request for half a dozen experimental sets of Mercury CB3 sparking plugs for testing on cars. | 16th Feb 1921 | Box 50 \ 2 Scan032 | |
| Returning the standardisation sheet for Mercury Sparking Plugs and noting a delay on another sheet. | 18th Feb 1921 | Box 50 \ 2 Scan033 | |
| Standardisation Sheet X.4295 for Mercury Sparking Plugs for a standard chassis. | 18th Feb 1921 | Box 50 \ 2 Scan034 | |
| Cover letter for the standardisation sheet on Mercury Sparking Plugs for Standard Chassis. | 18th Feb 1921 | Box 50 \ 2 Scan035 | |
| Requesting remarks and a signature on the attached standardisation sheet for Mercury Sparking Plugs. | 19th Feb 1921 | Box 50 \ 2 Scan036 | |
| Standardisation sheet for Mercury Sparking Plugs for the standard chassis. | 19th Feb 1921 | Box 50 \ 2 Scan037 | |
| Extract discussing the adoption of 'Mercury' plugs, their price, and repairability. | 21th Feb 1921 | Box 50 \ 2 Scan038 | |
| Standardisation of chassis parts, specifically replacing Lodge Plugs with Mercury GB3 Sparking Plugs. | 15th Feb 1921 | Box 50 \ 2 Scan039 | |
| The testing of Mercury CB3 sparking plugs and a recommendation for purchase. | 23th Dec 1918 | Box 50 \ 2 Scan040 | |
| Performance and recommendation of various spark plug brands for different markets. | 2nd Feb 1921 | Box 50 \ 2 Scan041 | |
| Proposal to reduce costs by repairing Mercury spark plugs in-house and establishing a system for testers to exchange them. | 22th Feb 1921 | Box 50 \ 2 Scan042 | |
| Request for Mercury plugs to be sent to the Sales Department for use on Demonstration Cars. | 22th Feb 1921 | Box 50 \ 2 Scan043 | |
| Clarifying the distribution and testing plan for an order of 500 Mercury plugs. | 19th Feb 1920 | Box 50 \ 2 Scan044 | |
| The use and distribution of 500 Mercury Sparking Plugs for various cars. | 8th Feb 1921 | Box 50 \ 2 Scan045 | |
| Suspected pre-ignition fault in 'Mercury' plugs compared to 'Champion' plugs. | 1st Mar 1921 | Box 50 \ 2 Scan046 | |
| Reporting a cracked porcelain on a Mercury plug after testing in a Goshawk engine. | 8th Mar 1921 | Box 50 \ 2 Scan047 | |
| Extract discussing the performance and leaking issues of Mercury plugs and the suitability of yellow brass plugs. | 1st Apr 1921 | Box 50 \ 2 Scan048 | |
| Standardization and performance of Mercury sparking plugs compared to Lodge plugs. | 18th Apr 1921 | Box 50 \ 2 Scan049 | |
| Clarifying the standardisation status and testing of Mercury Sparking Plugs. | 19th Apr 1921 | Box 50 \ 2 Scan050 | |
| 'Mercury' sparking plugs, advising consultation with the Experimental Department before ordering. | 4th Apr 1921 | Box 50 \ 2 Scan051 | |
| Performance of Champion and Mercury ignition plugs, with suggestions for design improvements. | 12th Apr 1921 | Box 50 \ 2 Scan052 | |
| Properties of steel versus yellow brass for a specific purpose. | 12th Apr 1921 | Box 50 \ 2 Scan053 | |
| Magneto requirements for the 40/50 engine, detailing tests and spark plug compatibility. | 5th May 1921 | Box 50 \ 2 Scan054 | |
| Results of testing ignition coils with varying numbers of secondary turns. | 5th May 1921 | Box 50 \ 2 Scan055 | |
| The testing and performance of Mercury spark plugs in comparison with Lodge plugs. | 11th Jan 1927 | Box 50 \ 2 Scan056 | |
| Issues with porcelain cracking and a soft brass nut on a component. | 11th May 1921 | Box 50 \ 2 Scan057 | |
| Request for a report on the behaviour of Mercury sparking plugs. | 11th May 1921 | Box 50 \ 2 Scan058 | |
| Request for a supply of 18 'Mercury' plugs to trial on demonstration cars. | 13th May 1921 | Box 50 \ 2 Scan059 | |
| The procurement of 'Mercury' plugs from company stores. | 19th May 1921 | Box 50 \ 2 Scan060 | |
| Letter to the Mercury Sparking Plug Co. requesting a visit from their representative to discuss tested plugs. | 24th May 1921 | Box 50 \ 2 Scan061 | |
| Letter from the Mercury Sparking Plug Company confirming a future visit. | 2nd Jun 1921 | Box 50 \ 2 Scan062 | |
| Follow-up letter to The Mercury Sparking Plug Co. regarding a promised visit to discuss their products. | 8th Aug 1921 | Box 50 \ 2 Scan063 | |
| Letter from the Mercury Sparking Plug Company regarding a missed appointment and rescheduling a works visit. | 12th Aug 1921 | Box 50 \ 2 Scan064 | |
| Pre-ignition issues caused by over-heated Champion ignition plugs and their potential design flaws. | 9th Sep 1921 | Box 50 \ 2 Scan065 | |
| Spark plug selection for engines and improvements to distribution and throttle exhaust heating. | 9th Sep 1921 | Box 50 \ 2 Scan066 | |
| Testing of Sphinx sparking plugs as a potential alternative to Mercury and Lodge plugs. | 4th Oct 1921 | Box 50 \ 2 Scan067 | |
| Ignition plug performance and lubrication issues on the 6.EX car. | 18th Oct 1921 | Box 50 \ 2 Scan068 | |
| Lubrication issues concerning grease syringes, spring shackles, and shock dampers, along with a note on a water leak. | 18th Oct 1921 | Box 50 \ 2 Scan069 | |
| Recent engine detonation issues in repaired cars, likely caused by petrol quality. | 20th Oct 1921 | Box 50 \ 2 Scan070 | |
| Observations on the performance of Mercury and Lodge ignition plugs under different test conditions and positions. | 28th Oct 1921 | Box 50 \ 2 Scan071 | |
| Shortage of Lodge plugs and requesting standardisation for a replacement. | 1st Mar 1922 | Box 50 \ 2 Scan072 | |
| Letter from the Mercury Sparking Plug Company suggesting a new combination of spark plugs. | 1st Mar 1922 | Box 50 \ 2 Scan073 | |
| Procedure for substituting Lodge plugs for Mercury plugs on 40/50 models due to a supply shortage. | 20th Jul 1922 | Box 50 \ 2 Scan074 | |
| Testing of K.L.G. ignition plugs and the temporary use of Lodge plugs for the 40/50 chassis. | 7th Sep 1922 | Box 50 \ 2 Scan075 | |
| Ordering and distribution of KLG plugs as a replacement for unavailable Mercury plugs for the 40/50 HP Chassis. | 9th Aug 1922 | Box 50 \ 2 Scan076 | |
| Instruction sheet detailing test results for a 'Scott Cut-out' electrical component. | 9th Dec 1920 | Box 50 \ 2 Scan077 | |
| Instruction sheet with handwritten electrical test results for shunt and series components under hot conditions. | 24th Jan 1919 | Box 50 \ 2 Scan078 | |
| Instructing the Shipping Office to despatch a 'Scott cut-out' to Mr. Royce for examination. | 15th Dec 1920 | Box 50 \ 2 Scan079 | |
| Test results of a 'Scott Cut-Out' apparatus under cold and hot operating conditions. | 15th Dec 1920 | Box 50 \ 2 Scan080 | |
| Tests of various electrical cut-outs, including Bleriot Phi and Rotax models. | 15th Dec 1920 | Box 50 \ 2 Scan081 | |
| Electrical quantities and torque specifications for a 20 HP starting motor. | 5th May 1919 | Box 50 \ 2 Scan082 | |
| The current drawn by the starter motor when turning the engine. | 6th Oct 1919 | Box 50 \ 2 Scan083 | |
| Starter motor's performance after being left out overnight. | 19th Nov 1920 | Box 50 \ 2 Scan084 | |
| Instructions detailing a starter motor test on a cold engine. | 19th Nov 1920 | Box 50 \ 2 Scan085 | |
| Table of chassis starter particulars for the 40/50 and Goshawk models. | 17th Dec 1920 | Box 50 \ 2 Scan086 | |
| Preliminary road test report on the 'Goshawk' chassis, detailing its behaviour and the performance of its components. | 1st Jan 1921 | Box 50 \ 2 Scan087 | |
| Device for starting up engines under cold conditions, based on a report from America. | 21th Feb 1921 | Box 50 \ 2 Scan088 | |
| Performance comparison of a Nickel-Iron (Ni-Fe) alkaline battery versus a standard acid battery, noting issues with cold starting. | 19th Mar 1921 | Box 50 \ 2 Scan089 | |
| Instruction sheet comparing the cold starting performance of a Nickel-Iron battery with a standard Chloride battery. | 21th Mar 1921 | Box 50 \ 2 Scan090 | |
| Test data for starting a Goshawk engine using a standard starter motor under cold and hot conditions. | 15th Apr 1921 | Box 50 \ 2 Scan091 | |
| Calculations for starter motor to engine transmission torque losses and ratios. | 9th Jun 1921 | Box 50 \ 2 Scan092 | |
| Letter discussing starter motor brake test results and performance curves. | 16th Jul 1921 | Box 50 \ 2 Scan093 | |
| Battery voltage drop, starter motor performance, and transmission efficiency in cold weather. | 16th Jul 1921 | Box 50 \ 2 Scan094 | |
| Cold weather starting performance, comparing with American cars and proposing tests. | 20th Jul 1921 | Box 50 \ 2 Scan095 | |
| Starter motor tests carried out on car 4-EX. | 20th Jul 1921 | Box 50 \ 2 Scan096 | |
| Test results for a standard motor under cold and hot conditions, showing speed, voltage, amperage, and temperature readings. | 11th Aug 1930 | Box 50 \ 2 Scan097 | |
| Test results for a motor with field coils in parallel, under cold and hot conditions. | 10th Aug 1911 | Box 50 \ 2 Scan098 | |
| Comparison of motor terminal voltages under different wiring configurations and temperatures. | 11th Aug 1930 | Box 50 \ 2 Scan099 | |
| Cold weather starting difficulties, turning the engine via the gearbox, and potential design changes. | 1st Feb 1922 | Box 50 \ 2 Scan100 | |
| Analysis of starting motor arrangements, comparing a direct Bendix drive to the existing gearbox-driven system. | 1st Feb 1922 | Box 50 \ 2 Scan101 | |
| Engine starting issues, piston fitting, starter motors, and gearbox design. | 1st Feb 1922 | Box 50 \ 2 Scan102 | |
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