| Description | Date | Identifier | |
| Test report on plug voltage at various plug gaps and water temperatures for different engine cylinders. | 17th Dec 1930 | Box 54 \ 5 Scan344 | |
| Analysis of high sparking voltages and ignition performance on the 20/25 chassis. | 7th Dec 1930 | Box 54 \ 5 Scan345 | |
| Sparking plug gaps, coil windings and distributor voltage for 20/25 and 40/50 chassis. | 17th Dec 1930 | Box 54 \ 5 Scan346 | |
| Ignition options for a six-cylinder engine with an 'interlaced' crank. | 8th Dec 1930 | Box 54 \ 5 Scan347 | |
| Examination report on faulty ignition units removed from chassis G.L.N.15. | 30th Dec 1930 | Box 54 \ 5 Scan348 | |
| Faulty coil operation and a proposed modification to the production test specification. | 30th Dec 1930 | Box 54 \ 5 Scan349 | |
| The examination and testing of ignition units, detailing a fault found with the coil due to impure paraffin wax. | 30th Dec 1930 | Box 54 \ 5 Scan350 | |
| Test report on a battery ignition contact breaker to determine when sparking occurs. | 20th Feb 1931 | Box 54 \ 5 Scan351 | |
| Request for six experimental ignition distributor cam and rotor sets for testing purposes. | 15th Jun 1931 | Box 54 \ 5 Scan352 | |
| Investigation into coil ignition misfires on the 20/25 HP chassis during full load pick up. | 3rd Aug 1931 | Box 54 \ 5 Scan353 | |
| Comparative test of ignition coils from various manufacturers and the development of a superior modified coil. | 3rd Aug 1931 | Box 54 \ 5 Scan354 | |
| Continued list of manufacturing and performance advantages of a coil design, compared to other makers. | 3rd Aug 1931 | Box 54 \ 5 Scan355 | |
| Clarifying the type of ignition coil used on a 25 HP car at Brooklands and updating on the design of an experimental coil. | 11th Sep 1931 | Box 54 \ 5 Scan356 | |
| Recommendations for updating the battery ignition system. | 14th Oct 1931 | Box 54 \ 5 Scan357 | |
| List of advantages for an outside primary coil, a reduced capacity circular condenser, and a lighter contact breaker lever. | 15th Oct 1931 | Box 54 \ 5 Scan358 | |
| List of suggestions for improvements to ignition system components. | 28th Nov 1931 | Box 54 \ 5 Scan359 | |
| Proposed change in electrical ignition coil design, comparing Delco with Bosch and Lucas models. | 28th Nov 1931 | Box 54 \ 5 Scan360 | |
| The best materials to prevent seizing of the contact lever pivot in a battery ignition distributor. | 4th Dec 1931 | Box 54 \ 5 Scan361 | |
| Improvements made to a battery ignition system compared to Delco. | 21th Dec 1931 | Box 54 \ 5 Scan362 | |
| Proposal to remove the magneto from the 20/25 chassis based on experimental test results. | 25th Jan 1932 | Box 54 \ 5 Scan363 | |
| Potential removal of the magneto from the 20/25 chassis and the required conditions. | 7th Jan 1932 | Box 54 \ 5 Scan364 | |
| The lubrication of the make and break lever pin for the 20/25 HP battery ignition. | 6th Feb 1932 | Box 54 \ 5 Scan365 | |
| Dimensions and lubrication for a post carrying the make and break lever for a 20/25 battery ignition system. | 30th Jan 1932 | Box 54 \ 5 Scan366 | |
| Letter from the National Accumulator Company regarding a misfiring issue on 20 HP cars. | 7th Mar 1932 | Box 54 \ 5 Scan367 | |
| The repair of a B.T.H. Magneto for a Kestrel IB engine, involving a Textolite timing wheel. | 11th Mar 1932 | Box 54 \ 5 Scan368 | |
| Letter to Mr. G.R.N. Minchin regarding the exchange of spare ignition units and a misfiring issue on a 20HP vehicle. | 8th Mar 1932 | Box 54 \ 5 Scan369 | |
| Letter from the National Accumulator Company regarding experimental ignition units and new batteries. | 9th Mar 1932 | Box 54 \ 5 Scan370 | |
| Letter to Mr. G.R.N. Minchin about sending new parts to fix a misfiring issue. | 10th Mar 1932 | Box 54 \ 5 Scan371 | |
| Arranging the despatch of parts to a customer free of charge. | 10th Mar 1932 | Box 54 \ 5 Scan372 | |
| Letter from National Accumulator Company Limited regarding the testing and return of ignition parts. | 11th Mar 1932 | Box 54 \ 5 Scan373 | |
| Correspondence regarding ignition system issues, including spark plug gaps, distributor performance, and coil insulation. | 18th Apr 1932 | Box 54 \ 5 Scan374 | |
| The ignition and spark plug types for the 20/25 model. | 22th Apr 1932 | Box 54 \ 5 Scan375 | |
| Requesting the return of loaned ignition parts to Mr. G.R.N. Minchin. | 5th May 1932 | Box 54 \ 5 Scan376 | |
| Experiments conducted on a 25HP ignition system, detailing tests on spark plugs and troubleshooting low-speed acceleration issues. | 30th May 1932 | Box 54 \ 5 Scan377 | |
| Technical memorandum regarding 25HP ignition systems, spark plug testing, and compression pressure analysis. | 1st Jun 1932 | Box 54 \ 5 Scan378 | |
| Patent specification 321,247 for preventing unauthorized use of motor vehicles and boats. | 26th Jan 1933 | Box 54 \ 5 Scan379 | |
| Responding to a patent specification for an ignition locking system. | 30th Jan 1933 | Box 54 \ 5 Scan380 | |
| Patent Specification No. 321247, requesting the return of a related document. | 31th Jan 1933 | Box 54 \ 5 Scan381 | |
| Cover memo attaching Patent Specification No. 321247. | 1st Feb 1933 | Box 54 \ 5 Scan382 | |
| Letter forwarding particulars and an illustration for a non-skidding device. | 12th Nov 1927 | Box 55 \ 1 Scan001 | |
| Clarifying a mistake in a recipient's name on a previous correspondence regarding a non-skidding device. | 8th Dec 1927 | Box 55 \ 1 Scan002 | |
| Letter requesting the return of papers concerning a non-skid invention. | 29th Nov 1927 | Box 55 \ 1 Scan003 | |
| Closing of a thank you note from Madge Browne. | 3rd Dec 1927 | Box 55 \ 1 Scan004 | |
| Letter to Mrs. Crown regarding a delay in returning the German original of a non-skidding device. | 3rd Dec 1927 | Box 55 \ 1 Scan005 | |
| Rejection of a limited-slip differential specification for their cars. | 23th Dec 1927 | Box 55 \ 1 Scan006 | |
| Complaint letter demanding the return of documents and threatening legal action for recovery. | 27th Dec 1927 | Box 55 \ 1 Scan007 | |
| Letter declining to examine an invention for vehicles, citing its limited application and the sufficiency of existing solutions like chains. | 29th Dec 1927 | Box 55 \ 1 Scan008 | |
| Invention for a non-skidding device, correcting the name of the inventor and requesting a direct reply. | 31th Dec 1927 | Box 55 \ 1 Scan009 | |
| Letter from Cap. Henri Alberti requesting a decision on a previously offered invention. | 27th Dec 1927 | Box 55 \ 1 Scan010 | |
| Letter to Capt. Henri Alberti regarding an invention sent for consideration. | 1st Dec 1927 | Box 55 \ 1 Scan011 | |
| Letter to Capt. Henri Alberti regarding a non-skidding device. | 2nd Jan 1928 | Box 55 \ 1 Scan012 | |
| Copy of a letter to Mrs. Crown regarding an invention for vehicles. | 29th Dec 1927 | Box 55 \ 1 Scan013 | |
| Letter to Mrs. Crown regarding the particulars of her German non-skidding device. | 3rd Jan 1928 | Box 55 \ 1 Scan014 | |
| Advertisement for a non-skid device using rubber bands instead of steel chains. | 15th Jan 1930 | Box 55 \ 1 Scan015 | |
| Advertisement for Goodyear rubber tyre chains sold by S. M. Evans & Co., Ltd. in Derby. | 24th Mar 1930 | Box 55 \ 1 Scan016 | |
| Letter received from Mr. Cooper of the India Tire & Rubber Co. regarding Silent Tread Tires. | 24th Mar 1930 | Box 55 \ 1 Scan017 | |
| Letter from India Tyre & Rubber Co. discussing criticisms of a non-skid tyre tread and the importance of brake adjustment. | 14th Mar 1930 | Box 55 \ 1 Scan018 | |
| Letter discussing the necessity of brake testing machines to address skidding issues and the plan to install them for India Super Tyres users. | 1st Jul 1932 | Box 55 \ 1 Scan019 | |
| Letter discussing the non-skidding properties of silent tread tyres compared to other types. | 26th Mar 1930 | Box 55 \ 1 Scan020 | |
| Developing an intermediate tyre to balance silence and safety. | 2nd Apr 1932 | Box 55 \ 1 Scan021 | |
| The testing of a Henley tyre, provided by Sir George Sutton, against a Dunlop tyre. | 2nd Apr 1932 | Box 55 \ 1 Scan022 | |
| Inability to test a single Henley tyre and the necessity of obtaining a full set of four for proper evaluation. | 7th Apr 1932 | Box 55 \ 1 Scan023 | |
| Meeting with the Piston Ring Co. about using nickel chrome cast iron liners in cylinder castings. | 6th Oct 1930 | Box 55 \ 1 Scan024 | |
| Follow-up on nickel percentage analysis mentioned in the S.A.E. Journal. | 6th Oct 1930 | Box 55 \ 1 Scan025 | |
| Material composition and properties of a cylinder liner. | 9th Oct 1930 | Box 55 \ 1 Scan026 | |
| Use of hardened .6 carbon steel for engine cylinder liners. | 9th Jan 1932 | Box 55 \ 1 Scan027 | |
| A.E.C. Specification No. 21 for Cast Iron Liners, detailing chemical analysis and hardness. | 25th Mar 1933 | Box 55 \ 1 Scan028 | |
| Investigation of phosphorous cast iron cylinder liners used by L.G.O.C. for the Peregrine engine. | 25th Mar 1933 | Box 55 \ 1 Scan029 | |
| Research, materials, and heat treatment for cylinder liners. | 10th Apr 1933 | Box 55 \ 1 Scan030 | |
| The heat treatment procedures for Peregrine cylinder liners. | 13th Apr 1933 | Box 55 \ 1 Scan031 | |
| The ordering, specifications, and heat treatment of Peregrine Cylinder Liners. | 28th Apr 1933 | Box 55 \ 1 Scan032 | |
| Alterations to the driving seat and rattles on a 20 HP car. | 28th Mar 1930 | Box 55 \ 1 Scan033 | |
| Modifications required for Mr. Royce's car, chassis 16-G4. | 14th Apr 1930 | Box 55 \ 1 Scan034 | |
| Urging a 'big push' on the 16-G4 car, listing specific upgrades required within a fortnight. | 7th May 1930 | Box 55 \ 1 Scan035 | |
| List of required parts and modifications for chassis 16-G4. | 8th May 1930 | Box 55 \ 1 Scan036 | |
| Required modifications and repairs for car 16.G.IV. | 15th May 1931 | Box 55 \ 1 Scan037 | |
| Alterations to a car, improvements in performance, and plans for a new 'Japan' unit. | 16th May 1930 | Box 55 \ 1 Scan038 | |
| Modifications to engine unit Cos.C.3 and its associated chassis, detailing changes to the crankshaft, spring drive, fan, and other components. | 16th May 1930 | Box 55 \ 1 Scan039 | |
| 25 HP car's handling issues, suggesting the front springs are too highly rated and proposing a modification to the dampers. | 23th May 1930 | Box 55 \ 1 Scan040 | |
| Modifications to a car, including a crankshaft replacement, speedometer alteration, and exhaust system upgrade. | 23th May 1931 | Box 55 \ 1 Scan041 | |
| Load adjustments for 16-G4 shock absorbers. | 26th May 1930 | Box 55 \ 1 Scan042 | |
| Order for two 20 HP front springs with a modified loaded poundage for Mr. Royce's car. | 10th Jul 1930 | Box 55 \ 1 Scan043 | |
| Repairs and modifications to a car for 'R', and speculation on a future vehicle. | 10th Mar 1931 | Box 55 \ 1 Scan044 | |
| Fitting a new 'P' type steering and pedals to a car, and arranging for a summer examination. | 19th Mar 1931 | Box 55 \ 1 Scan045 | |
| Instruction memo to arrange for chromium plating on various car parts. | 23th Mar 1931 | Box 55 \ 1 Scan046 | |
| Design approval and body construction for a 25HP Special Touring Saloon. | 11th Aug 1931 | Box 55 \ 1 Scan047 | |
| Blueprint of a proposed special touring saloon car. | 27th Jul 1931 | Box 55 \ 1 Scan048 | |
| Letter to coachbuilders Park Ward & Co. Ltd. regarding the specifications for a 25. HP. Special Touring Saloon for Sir Henry Royce. | 21th Aug 1931 | Box 55 \ 1 Scan049 | |
| Specification for the coachwork of a four-door sports saloon on a 25HP chassis. | 23th Oct 1931 | Box 55 \ 1 Scan050 | |
| Body building specifications covering scuttle isolation, finish, roof, spare wheel, wheels, and delivery details. | 23th Oct 1931 | Box 55 \ 1 Scan051 | |
| Build arrangements and special features for a 'U' series chassis and a Special Touring Saloon body. | 22th Aug 1931 | Box 55 \ 1 Scan052 | |
| The design of a louvred bonnet and scuttle for a 25HP 'U' Series Special Touring Saloon. | 2nd Sep 1931 | Box 55 \ 1 Scan053 | |
| Letter from coachbuilders Park, Ward & Co. requesting the switch lock number for Sir H. Royce's chassis. | 4th Sep 1931 | Box 55 \ 1 Scan054 | |
| Confirming a request for a louvred bonnet for the 20/25 HP 'U' Series Special Touring Saloon. | 7th Sep 1931 | Box 55 \ 1 Scan055 | |
| Letter to Park Ward & Co. Ltd. regarding the switch lock number for Sir Henry Royce's car. | 11th Sep 1931 | Box 55 \ 1 Scan056 | |
| Experimental instructions for a new car on the 20/25 'U' Series chassis, detailing engine modifications. | 14th Sep 1931 | Box 55 \ 1 Scan057 | |
| List of specifications and instructions for chassis and body components including the bonnet, gearbox, and fittings. | 26th Jan 1931 | Box 55 \ 1 Scan058 | |
| List of technical instructions and updates for various vehicle components and schematics. | 26th Aug 1931 | Box 55 \ 1 Scan059 | |
| Letter from coachbuilders Park Ward & Co. Ltd acknowledging the switch lock number for Sir Henry Royce's car. | 15th Sep 1931 | Box 55 \ 1 Scan060 | |
| Confirming modifications for a Special Touring Saloon U.Series chassis, including an extended exhaust and noting a delivery delay. | 15th Sep 1931 | Box 55 \ 1 Scan061 | |
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