| Description | Date | Identifier | |
| The lubricating properties and performance of paraffin base hydrocarbons in petrol engines. | 5th Oct 1928 | Box 32 \ 4 Scan275 | |
| Page from 'The ELECTRICAL REVIEW' detailing tests for high-grade insulating oils. | 5th Oct 1928 | Box 32 \ 4 Scan276 | |
| Journal page detailing various testing procedures for oils and an article on international salesmanship. | 5th Oct 1928 | Box 32 \ 4 Scan277 | |
| Request for a comparative analysis of two used engine oil samples, one from a standard S.S. engine and the other from a Chrysler. | 6th Apr 1929 | Box 32 \ 4 Scan278 | |
| Request from Messrs. Duckham for the approval of their 'ADCOL' New Process Oil. | 27th Apr 1929 | Box 32 \ 4 Scan279 | |
| Use of Vacuum BB oil as an alternative, as no tests have been conducted on Vacuum A oil. | 29th Apr 1929 | Box 32 \ 4 Scan280 | |
| Stating no objection to the use of Duckham's oil. | 27th Nov 1929 | Box 32 \ 4 Scan281 | |
| Composition and use of 'Esso' super-fuel in cars. | 18th Jul 1930 | Box 32 \ 4 Scan282 | |
| Internal memorandum regarding 'Esso' and Rolls-Royce Cars, advising to say nothing on the matter. | 23th Jun 1930 | Box 32 \ 4 Scan283 | |
| Customer's query about using Valrolene oil for the engine of chassis 62-RC. | 2nd Feb 1931 | Box 32 \ 4 Scan284 | |
| Suitability of Valrolene oil for chassis No. 62-RC. | 9th Feb 1931 | Box 32 \ 4 Scan285 | |
| Clarifying that Messrs. Duckham has no authority to state their oils are approved, but their H.B.B. grease is approved. | 24th Jun 1931 | Box 32 \ 4 Scan286 | |
| Laboratory report on a sample of 'ESSO' Motor Spirit. | 22th Sep 1931 | Box 32 \ 4 Scan287 | |
| Laboratory report detailing the results of a distillation test on a sample of 'Esso' (French) motor spirit. | 3rd Oct 1931 | Box 32 \ 4 Scan288 | |
| Reprint from The Electrical Times discussing developments in mercury vapour rectifiers. | 9th Jun 1921 | Box 32 \ 5 Scan001 | |
| Reprint from 'The Electrical Times' discussing recent developments in mercury vapour rectifiers. | 9th Jun 1921 | Box 32 \ 5 Scan002 | |
| Suitable rectifiers for trickle charging chassis batteries. | 27th Oct 1922 | Box 32 \ 5 Scan003 | |
| Different types of rectifiers for chassis batteries, recommending the B.T.H. Tungar rectifier. | 31th Oct 1922 | Box 32 \ 5 Scan004 | |
| Attached leaflet for a Tungar rectifier for battery charging. | 8th Nov 1922 | Box 32 \ 5 Scan005 | |
| Leaflet for the Tungar Battery Charger and an associated Charging Board for direct current use. | 2nd Nov 1922 | Box 32 \ 5 Scan006 | |
| Letter from the Hewettic Electric Company regarding their new, larger capacity Mercury Vapour Rectifiers. | 21th Sep 1921 | Box 32 \ 5 Scan007 | |
| Product sheet for a Hewittic Electric Company Limited Mercury Vapour Rectifier. | 21th Sep 1921 | Box 32 \ 5 Scan008 | |
| Product data sheet for a Mercury Vapour Rectifier from the Hewittic Electric Company Limited. | 22th Nov 1922 | Box 32 \ 5 Scan009 | |
| Comparison of efficiencies between B.T.H. Tungar and Johnson & Phillips relay operated rectifiers. | 22th Nov 1922 | Box 32 \ 5 Scan010 | |
| Requesting an enquiry be sent to Johnson & Phillips Ltd. for a relay-operated rectifier for charging chassis batteries. | 22th Nov 1922 | Box 32 \ 5 Scan011 | |
| Inquiry to Johnson & Phillips Ltd. for particulars of a Relay Operated Rectifier for charging chassis batteries. | 24th Nov 1922 | Box 32 \ 5 Scan012 | |
| Quotation from Johnson & Phillips Ltd for a J.& P. Full wave converter and battery charger. | 28th Nov 1922 | Box 32 \ 5 Scan013 | |
| Particulars of a Johnson & Phillips rectifier for charging 12-volt batteries and comparing it to a B.T.H. Tungar rectifier. | 29th Nov 1922 | Box 32 \ 5 Scan014 | |
| Cover page for the J. & P. A.C. to D.C. (full wave) converter. | 1st Oct 1922 | Box 32 \ 5 Scan015 | |
| Important notice detailing the particulars required when ordering J. & P. Converters. | 7th Dec 1922 | Box 32 \ 5 Scan016 | |
| Letter responding to an enquiry about Tungar Battery Chargers, with an accompanying descriptive folder. | 7th Dec 1922 | Box 32 \ 5 Scan017 | |
| Sending a Johnson & Phillips Rectifier to the makers for repair. | 3rd Jun 1925 | Box 32 \ 5 Scan018 | |
| Testing and recommendation of a Philips Rectifier for charging chassis batteries. | 16th Nov 1925 | Box 32 \ 5 Scan019 | |
| Testing and performance of a Philips Rectifier. | 9th Nov 1925 | Box 32 \ 5 Scan020 | |
| Continuation of a report detailing results and observations from electrical charging tests on a valve. | 24th Dec 1925 | Box 32 \ 5 Scan021 | |
| Price confirmation for a Johnson & Philips full wave converter. | 24th Dec 1925 | Box 32 \ 5 Scan022 | |
| Circuit diagram illustrating the connections for a Fellows A.C. Rectifier. | 5th Dec 1929 | Box 32 \ 5 Scan023 | |
| Car dynamo output and alternative battery charging technologies. | 5th Dec 1929 | Box 32 \ 5 Scan024 | |
| Standard armatures and trickle charging arrangements for car dynamos. | 16th Dec 1929 | Box 32 \ 5 Scan025 | |
| Metal rectifiers suitable for charging chassis batteries from an alternating current supply. | 16th Dec 1929 | Box 32 \ 5 Scan026 | |
| Trickle charging, efficiency, and comparative costs of metallic rectifying units versus Tungar type units. | 16th Dec 1929 | Box 32 \ 5 Scan027 | |
| Dynamo output, increased electrical load from features, and battery charging methods. | 23th Dec 1929 | Box 32 \ 5 Scan028 | |
| Quotation for a Westinghouse rectifier set for car batteries. | 30th Jan 1930 | Box 32 \ 5 Scan029 | |
| Proposal for a rectifier set in the garage with a security measure to prevent unofficial use. | 1st Feb 1930 | Box 32 \ 5 Scan030 | |
| Letter inquiring about making a quoted metal rectifier set portable for charging batteries. | 24th Apr 1930 | Box 32 \ 5 Scan031 | |
| Letter from Westinghouse regarding the specifications and arrangement of an R.P.10.F rectifier for floor mounting and battery charging. | 28th Apr 1930 | Box 32 \ 5 Scan032 | |
| Letter to Westinghouse Brake & Saxby Signal Co. Ltd requesting weight and dimension particulars for an RP.10F rectifier apparatus. | 30th Apr 1930 | Box 32 \ 5 Scan033 | |
| Letter from Westinghouse regarding the supply and arrangement of an R.P.10.F. rectifier, including a blueprint. | 1st May 1930 | Box 32 \ 5 Scan034 | |
| Request to obtain a Westinghouse Metal Rectifier Set for charging car batteries in the experimental garage. | 6th May 1930 | Box 32 \ 5 Scan035 | |
| Continuation discussing an electrical apparatus for converting current and ordering information from Westinghouse Co. | 6th May 1930 | Box 32 \ 5 Scan036 | |
| Metal rectifier equipment for electro-plating purposes. | 6th May 1930 | Box 32 \ 5 Scan037 | |
| Letter from Westinghouse Brake & Saxby Signal Company enclosing a blueprint of instructions for a rectifier set. | 7th Jul 1930 | Box 32 \ 5 Scan038 | |
| Instructions for use for an RP. 10 - F. Rectifier Set manufactured by The Westinghouse Brake and Saxby Signal Co Ltd. | 8th Aug 1930 | Box 32 \ 5 Scan039 | |
| From EFC to EJJ regarding the omission of the metal rectifier apparatus. | 8th Aug 1930 | Box 32 \ 5 Scan040 | |
| Return of a U3 Osram rectifying valve to the General Electric Co. Ltd. for examination. | 9th Apr 1932 | Box 32 \ 5 Scan041 | |
| Letter to the General Electric Co. Ltd. regarding a faulty H.T. Rectifying Valve being returned for examination. | 9th Apr 1932 | Box 32 \ 5 Scan042 | |
| Letter to Westinghouse Brake & Saxby Signal Co. Ltd. declining to fit the Westric Charger socket as standard equipment. | 4th May 1933 | Box 32 \ 5 Scan043 | |
| Modifications to drawing LeC.2121 for the EAC battery ignition system, including feedback from Mr. Royce. | 10th Aug 1925 | Box 32 \ 5 Scan044 | |
| Investigations into improving the life of ignition contact points for the Phantom car. | 29th May 1928 | Box 32 \ 5 Scan045 | |
| From EFC to RHC requesting two battery ignition contact breaker springs with a larger set. | 26th Oct 1926 | Box 32 \ 5 Scan046 | |
| Required modifications to the ignition systems of various experimental chassis. | 9th Nov 1926 | Box 32 \ 5 Scan047 | |
| Change in material and force requirements for springs in a battery ignition contact breaker. | 23th Dec 1926 | Box 32 \ 5 Scan048 | |
| Requesting contact breaker springs to continue a 10,000-mile contact breaker run test. | 10th Jan 1927 | Box 32 \ 5 Scan049 | |
| Dispatch of special contact breaker springs. | 13th Jan 1927 | Box 32 \ 5 Scan050 | |
| Extract discussing modifications to a Bosch ignition unit with a diagram of an umbrella-style rotor designed for air circulation. | 17th Jan 1927 | Box 32 \ 5 Scan051 | |
| Modification to the battery ignition umbrella rotor to improve insulation. | 26th Feb 1927 | Box 32 \ 5 Scan052 | |
| Modifications to the ignition system on experimental chassis, including adding holes to distributors. | 1st Mar 1927 | Box 32 \ 5 Scan053 | |
| Anxiously awaiting a satisfactory set of stronger springs for a battery ignition contact breaker. | 2nd Mar 1927 | Box 32 \ 5 Scan054 | |
| New and replacement parts for the ignition distributor on Phantom and EAC.VII models. | 8th Mar 1927 | Box 32 \ 5 Scan055 | |
| Cover note for a blueprint showing the radial movement of an offset contact breaker rocker for battery ignition. | 22th Mar 1927 | Box 32 \ 5 Scan056 | |
| Graph showing make ratio versus speed curves for a standard contact breaker with standard and increased rated springs at various gaps. | 31th Mar 1937 | Box 32 \ 5 Scan057 | |
| Blank document page bearing a Print Room stamp from Derby. | 31th Mar 1927 | Box 32 \ 5 Scan058 | |
| Burning ignition contact points on vehicle 10-EX due to oil presence and the proposed solution. | 8th Jun 1927 | Box 32 \ 5 Scan059 | |
| Request from EFC to HHC for two further mushroom type rotors for battery ignition tests. | 5th Jul 1927 | Box 32 \ 5 Scan060 | |
| Cases of surface tracking failure on moulded battery ignition rotor bodies. | 23th Aug 1927 | Box 32 \ 5 Scan061 | |
| Failure of bakelite distributor heads and the effectiveness of a safety gap. | 23th Aug 1927 | Box 32 \ 5 Scan062 | |
| Test report on a new experimental mushroom type H.T. rotor, comparing its performance on open circuit to the standard type. | 22th Oct 1927 | Box 32 \ 5 Scan063 | |
| Distributor head sparking and corrosion, comparing the standard rotor to a 'mushroom' rotor and suggesting a redesign with vanes. | 22th Oct 1927 | Box 32 \ 5 Scan064 | |
| Standardisation and performance of a mushroom type H.T. rotor, noting issues with corrosion. | 2nd Nov 1927 | Box 32 \ 5 Scan065 | |
| Standardising battery ignition components and a potential tracking issue in the distributor. | 8th Nov 1927 | Box 32 \ 5 Scan066 | |
| Reliability and potential redesign of the battery ignition distributor head and rotor. | 14th Nov 1927 | Box 32 \ 5 Scan067 | |
| 10,000-mile test of a mushroom-type H.T. rotor and proposing the addition of vanes to prevent corrosion. | 6th Dec 1927 | Box 32 \ 5 Scan068 | |
| Supplying two modified mushroom type rotors and requesting fingers to be fitted for specific test cars. | 6th Dec 1927 | Box 32 \ 5 Scan069 | |
| Requesting new keyways be slotted in two mushroom type rotors to suit a standard contact breaker. | 12th Dec 1927 | Box 32 \ 5 Scan070 | |
| New sample springs for Make and Break Levers, piece no. D.50793, focusing on material and avoiding plating. | 13th Oct 1927 | Box 32 \ 5 Scan071 | |
| Improvements to battery ignition, plugs, and distributor components, and a query on porcelain plug manufacturing. | 28th Nov 1927 | Box 32 \ 5 Scan072 | |
| Decision memo on not adding vanes to the umbrella rotor for the battery ignition system. | 8th Dec 1927 | Box 32 \ 5 Scan073 | |
| Design and improvement of battery ignition systems, including contacts, distributors, and coils. | 9th Dec 1927 | Box 32 \ 5 Scan074 | |
| Provision of mushroom type rotors with altered keyways for chassis testing. | 20th Dec 1927 | Box 32 \ 5 Scan075 | |
| Requesting a modification to fit a mushroom type rotor to a 12-EX car. | 2nd Mar 1928 | Box 32 \ 5 Scan076 | |
| Instructions and examination results for a new standard contact breaker design. | 27th Jul 1928 | Box 32 \ 5 Scan077 | |
| Misfiring issue on vehicle 9-EX at low speeds, attributing it to the contact breaker and tungsten points, and requesting a new part to be fitted. | 13th Sep 1928 | Box 32 \ 5 Scan078 | |
| Changing the finish on a battery ignition contact breaker's fixed point screw from black oxidised to electro-tinned to improve electrical reliability. | 22th Sep 1928 | Box 32 \ 5 Scan079 | |
| Factors affecting the ignition lever position on Phantom and 20 HP models. | 25th Oct 1928 | Box 32 \ 5 Scan080 | |
| Continued instructions for checking ignition system quantities and timings for 20 HP and Phantom chassis. | 25th Oct 1928 | Box 32 \ 5 Scan081 | |
| Technical note on diagnosing ignition timing faults related to the contact breaker and quadrant position. | 2nd Nov 1928 | Box 32 \ 5 Scan082 | |
| Test report on stainless steel contact points for battery ignition. | 2nd Nov 1928 | Box 32 \ 5 Scan083 | |
| The testing of nickel silver contact breaker levers fitted with tungsten points. | 2nd Nov 1928 | Box 32 \ 5 Scan084 | |
| Test report on Nickel Silver contact breaker levers after a 10,000-mile equivalent bench test. | 2nd Nov 1928 | Box 32 \ 5 Scan085 | |
| The material improvement of battery ignition contact breaker cams hardened by the 'Cloudburst' process. | 15th Sep 1930 | Box 32 \ 5 Scan086 | |
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