| Description | Date | Identifier | |
| Letter from S. Wolf & Co. Ltd. (Solex) regarding a requested catalogue for their carburettor. | 20th Feb 1922 | Box 121 \ 2 scan0001 | |
| Letter from S. Wolf & Co Ltd proposing a 35m/m Horizontal Solex Carburettor for a three-litre engine. | 6th Mar 1922 | Box 121 \ 2 scan0002 | |
| Letter from S. Wolf & Co Ltd regarding sending a drawing for a suitable 'Solex' carburettor. | 1st Mar 1922 | Box 121 \ 2 scan0003 | |
| Letter from Solex Ltd. to Colonel Fell enquiring about the possibility of testing their 'Solex' carburettors at Derby. | 31th Mar 1928 | Box 121 \ 2 scan0004 | |
| Letter addressed to Colonel Fell regarding the principles and benefits of the 'Solex' carburettor. | 31th Mar 1928 | Box 121 \ 2 scan0005 | |
| Page 2 of a letter addressed to Colonel Fell, D.S.C., discussing a test and arranging a meeting in Derby. | 31th Mar 1928 | Box 121 \ 2 scan0006 | |
| Forwarding an offer from the Solex Company to loan a carburettor for testing, with a warning about exaggerated claims. | 3rd Apr 1923 | Box 121 \ 2 scan0007 | |
| Letter to L. Mantell of Solex Ltd., acknowledging his correspondence and advising it has been passed to Mr. Royce. | 3rd Apr 1928 | Box 121 \ 2 scan0008 | |
| Letter from Solex Ltd. to Colonel Fell regarding a business matter and his assistance. | 10th Apr 1928 | Box 121 \ 2 scan0009 | |
| Offer from Solex to provide a set of their carburettors for testing. | 26th Apr 1928 | Box 121 \ 2 scan0010 | |
| Offer from Solex to provide a set of their carburetters for testing. | 28th Apr 1928 | Box 121 \ 2 scan0011 | |
| Letter to Solex Ltd. expressing interest in testing their carburetter on a 40/50 HP engine and providing its specifications. | 3rd May 1928 | Box 121 \ 2 scan0012 | |
| Letter from Solex Ltd. discussing their carburettor capabilities and proposing a demonstration. | 5th May 1928 | Box 121 \ 2 scan0013 | |
| Letter from Solex Ltd. to Messrs. Rolls Royce Ltd. regarding a demonstration of an instrument. | 5th May 1928 | Box 121 \ 2 scan0014 | |
| Letter to Solex Ltd. regarding arranging a convenient day for a visit. | 7th May 1928 | Box 121 \ 2 scan0015 | |
| Letter from Solex Ltd. concerning suggestions for exhaust and induction pipe design for a 40/50 HP car. | 11th May 1928 | Box 121 \ 2 scan0016 | |
| Page 2 of a letter from Solex Ltd. discussing a carburettor and arranging a road and bench test. | 11th May 1928 | Box 121 \ 2 scan0017 | |
| Letter to Messrs. Solex Ltd. enclosing blueprints for the Phantom and 20 HP. Cylinder head. | 12th May 1928 | Box 121 \ 2 scan0018 | |
| Letter from Solex Ltd. regarding Blue Prints of the Phantom and 20 HP Cylinder Head. | 15th May 1928 | Box 121 \ 2 scan0019 | |
| Letter from Solex Ltd. discussing the preliminary testing of their carburettors on the 20 HP and Phantom engines. | 5th Jun 1928 | Box 121 \ 2 scan0020 | |
| Letter from Solex Ltd. discussing bench tests, road tests, and engine characteristics. | 5th Jun 1928 | Box 121 \ 2 scan0021 | |
| Letter from the Experimental Department to Solex Ltd. arranging a test for a 20 HP engine unit. | 7th Jun 1928 | Box 121 \ 2 scan0022 | |
| Letter from Solex Ltd. arranging a test with a Solex Carburettor on a 20 HP engine unit. | 8th Jun 1928 | Box 121 \ 2 scan0023 | |
| Letter from carburettor manufacturer Solex Ltd. confirming comparative bench tests against a factory model on a 20 HP engine and proposing a road test. | 14th Jun 1928 | Box 121 \ 2 scan0024 | |
| The second and final page of a letter from Solex Ltd. | 14th Jun 1928 | Box 121 \ 2 scan0025 | |
| Letter from Solex Ltd. regarding carburettor bench tests and a proposed road test. | 19th Jun 1928 | Box 121 \ 2 scan0026 | |
| Performance report on a Solex carburetter fitted to a 20 HP car, detailing issues with slow running and throttle response. | 21th Jun 1928 | Box 121 \ 2 scan0027 | |
| Letter from Solex Ltd. discussing carburettor performance on bench vs. road tests. | 25th Jun 1928 | Box 121 \ 2 scan0028 | |
| Letter from Solex Ltd. discussing carburettor performance, the difference between road and bench tuning, and postponing a visit. | 25th Jun 1928 | Box 121 \ 2 scan0029 | |
| Letter from Solex Ltd. regarding a carburettor ready for road testing on a 20 HP car. | 9th Jul 1928 | Box 121 \ 2 scan0030 | |
| Letter to Solex Ltd. urging them to complete their tests on a car and confirming a telegram was sent. | 10th Jul 1928 | Box 121 \ 2 scan0031 | |
| Post Office telegram concerning the arrival of Mantell for a meeting with Mr Hives. | 10th Jul 1928 | Box 121 \ 2 scan0032 | |
| Letter from Solex Ltd. to Rolls Royce Ltd. confirming the visit of their Mr. Mantell for tests. | 11th Jul 1928 | Box 121 \ 2 scan0033 | |
| Letter from Solex Ltd. regarding carburettor tests and drawings for an induction system on a 40/50 hp engine. | 16th Aug 1928 | Box 121 \ 2 scan0034 | |
| Letter to Solex Ltd. arranging a meeting with Mr. Mantell and their Research Department. | 17th Aug 1928 | Box 121 \ 2 scan0035 | |
| Letter from Solex Ltd. arranging a visit to the works by their Chief of Research. | 18th Aug 1928 | Box 121 \ 2 scan0036 | |
| Letter to Solex Ltd. arranging a meeting for the coming Wednesday. | 20th Aug 1928 | Box 121 \ 2 scan0037 | |
| Letter from Solex Ltd. regarding an induction pipe drawing and a new carburettor design for a 40 HP engine. | 8th Sep 1928 | Box 121 \ 2 scan0038 | |
| Letter to The Solex Works asking for an expected completion date for carburettors. | 17th Oct 1928 | Box 121 \ 2 scan0039 | |
| Confirming the need to finish Solex induction pipes in order to test their carburetters. | 17th Oct 1928 | Box 121 \ 2 scan0040 | |
| Letter from carburettor manufacturer Solex Ltd. acknowledging receipt of an order. | 18th Oct 1928 | Box 121 \ 2 scan0041 | |
| Letter to Solex Ltd. chasing the delivery of carburettors for a 40/50 HP car. | 24th Oct 1928 | Box 121 \ 2 scan0042 | |
| Letter from Solex Ltd. regarding a delay in the delivery of carburettors promised for testing. | 25th Oct 1928 | Box 121 \ 2 scan0043 | |
| Letter from Solex Ltd. regarding a special carburettor for the Phantom engine and arrangements for bench testing. | 29th Oct 1928 | Box 121 \ 2 scan0044 | |
| Letter from Solex Ltd. concerning a special jet system. | 29th Oct 1928 | Box 121 \ 2 scan0045 | |
| Letter to The Solex Carb. Co. Ltd. requesting carburettors for an engine test run. | 2nd Nov 1928 | Box 121 \ 2 scan0046 | |
| Letter from Solex Ltd. regarding a mishap and delay in dispatching a special Dual Carburettor for testing. | 3rd Nov 1928 | Box 121 \ 2 scan0047 | |
| Letter from Solex Ltd. assuring their best attention. | 3rd Nov 1928 | Box 121 \ 2 scan0048 | |
| Letter from Solex Ltd. regarding the dispatch of four special choke tubes. | 7th Nov 1928 | Box 121 \ 2 scan0049 | |
| Letter to The Solex Co. Ltd. confirming readiness of an engine and induction pipe for testing. | 9th Nov 1928 | Box 121 \ 2 scan0050 | |
| Letter from Solex Ltd. acknowledging a previous letter and arranging a meeting for the following week. | 10th Nov 1928 | Box 121 \ 2 scan0051 | |
| Letter to Solex Carburetter Co. Ltd. outlining issues found during engine testing with their carburetters. | 12th Nov 1928 | Box 121 \ 2 scan0052 | |
| Letter from Solex Ltd. regarding the supply of parts for a Phantom engine bench test. | 17th Nov 1928 | Box 121 \ 2 scan0053 | |
| Letter from Solex Ltd. acknowledging a telegram postponing carburettor tests and awaiting a new date. | 22th Nov 1928 | Box 121 \ 2 scan0054 | |
| Letter to Solex Ltd. about postponing carburetter tests and scheduling a visit for Mr. Mantell. | 23th Nov 1928 | Box 121 \ 2 scan0055 | |
| Letter from Solex Ltd. acknowledging receipt of a letter and awaiting a telegram. | 24th Nov 1928 | Box 121 \ 2 scan0056 | |
| Letter to Solex Ltd. arranging for Mr. Mantell to observe carburetter tests on a car. | 26th Nov 1928 | Box 121 \ 2 scan0057 | |
| Letter from Solex Ltd. arranging to assist the Experimental Department with carburettor road tests. | 27th Nov 1928 | Box 121 \ 2 scan0058 | |
| Letter to Solex Ltd. advising they are ready for Mr. Mantell to attend carburetter tests. | 28th Nov 1928 | Box 121 \ 2 scan0059 | |
| Letter from Solex Ltd. concerning carburettor testing and performance improvements. | 5th Dec 1928 | Box 121 \ 2 scan0060 | |
| Letter from Solex Ltd. regarding a special jet system and throttle curve tests. | 5th Dec 1928 | Box 121 \ 2 scan0061 | |
| Letter to Solex Ltd. inviting Mr. Mantell to attend carburetter tests. | 28th Nov 1928 | Box 121 \ 2 scan0062 | |
| Letter from Solex Ltd. proposing to send a foreman to test a new jet system from their Paris Research Department. | 10th Dec 1928 | Box 121 \ 2 scan0063 | |
| Letter to Messrs. Solex Ltd. concerning the delay of a car test until after Christmas. | 11th Dec 1928 | Box 121 \ 2 scan0064 | |
| Letter from Solex Ltd. arranging a road test for after Christmas, suggesting the 7th of the next month. | 12th Dec 1928 | Box 121 \ 2 scan0065 | |
| The second page of a typed letter from Solex Ltd. | 12th Dec 1928 | Box 121 \ 2 scan0066 | |
| Letter from Solex Ltd. arranging a meeting with their French Engineer for the 7th of the next month. | 18th Dec 1928 | Box 121 \ 2 scan0067 | |
| Letter to Solex Ltd. arranging to fit a carburetter and induction pipes to a car for testing. | 19th Dec 1928 | Box 121 \ 2 scan0068 | |
| Letter from Solex Ltd. arranging a road test for a Solex carburettor on a new Phantom engine. | 20th Dec 1928 | Box 121 \ 2 scan0069 | |
| Letter to Solex Ltd. regarding performance and consumption tests of their double-throat carburetter on a 40/50 HP engine. | 5th Jan 1929 | Box 121 \ 2 scan0070 | |
| Letter discussing carburetter modifications to address high petrol consumption. | 30th Jan 1929 | Box 121 \ 2 scan0071 | |
| Graph of power curves for a Phantom engine with a Solex twin carburetter, comparing different choke sizes. | 30th Jan 1929 | Box 121 \ 2 scan0072 | |
| Letter from Solex discussing carburettor tests and requested modifications for a 40/50 HP Phantom. | 11th Jan 1929 | Box 121 \ 2 scan0073 | |
| Letter from Solex Ltd. concerning carburettor modifications and comparative test readings. | 11th Jan 1929 | Box 121 \ 2 scan0074 | |
| Letter from Solex Ltd. requesting specific comparative speed, acceleration, and consumption tests for different carburettor choke settings. | 19th Jan 1929 | Box 121 \ 2 scan0075 | |
| Letter discussing carburettor tests, focusing on the effects of centrifugal force on the float chamber during cornering. | 19th Jan 1929 | Box 121 \ 2 scan0076 | |
| The concluding page of a letter from Solex Ltd. | 19th Jan 1929 | Box 121 \ 2 scan0077 | |
| Comparing expanding carburetters with static types from Solex, Stromberg and Zenith, with a view to developing the Phantom carb. | 23th Jan 1929 | Box 121 \ 2 scan0078 | |
| Continued analysis of the advantages and disadvantages of a carburettor type, this being page 2. | 23th Jan 1929 | Box 121 \ 2 scan0079 | |
| Carburettor performance issues, including a diagram illustrating fuel delivery at small throttle openings. | 23th Jan 1929 | Box 121 \ 2 scan0080 | |
| Page describing engine stalling from sudden throttle opening and fuel supply issues, comparing car and aero engines. | 23th Jan 1929 | Box 121 \ 2 scan0081 | |
| The operation of the Phantom carburetter, focusing on its low-speed and acceleration performance. | 23th Jan 1929 | Box 121 \ 2 scan0082 | |
| Carburettor performance, comparing static types like the Twin Solex on the Phantom with other models. | 23th Jan 1929 | Box 121 \ 2 scan0083 | |
| Proposed carburettor design with a low speed choke and diffuser jets. | 23th Jan 1929 | Box 121 \ 2 scan0084 | |
| Page explaining carburetter depression and operation, with two illustrative diagrams. | 23th Jan 1929 | Box 121 \ 2 scan0085 | |
| Carburetter design, including butterfly valves, suction pistons, and performance advantages. | 23th Jan 1929 | Box 121 \ 2 scan0086 | |
| Carburetter design principles, specifically atomisation and acceleration. | 6th Feb 1929 | Box 121 \ 2 scan0087 | |
| Letter from Solex Ltd. regarding modifications to a 34 m/m Choke Tube to address noise and improve performance. | 6th Feb 1929 | Box 121 \ 2 scan0088 | |
| Concluding page of a letter from Solex Ltd. regarding parts readiness. | 6th Feb 1929 | Box 121 \ 2 scan0089 | |
| Successful trial of a Solex carburetter on a Phantom model. | 2nd Feb 1929 | Box 121 \ 2 scan0090 | |
| Solex carburetter tests conducted on a Phantom model. | 7th Feb 1929 | Box 121 \ 2 scan0091 | |
| Comparison of engine performance using different carburettor and induction systems. | 7th Feb 1929 | Box 121 \ 2 scan0092 | |
| Carburettor choke sizes and their impact on low-speed performance and torque. | 7th Feb 1929 | Box 121 \ 2 scan0093 | |
| Analysis of induction systems and carburettors, comparing fuel distribution and performance on various engines. | 7th Feb 1929 | Box 121 \ 2 scan0094 | |
| Advantages of the SS expanding carburettor and suggesting further development and comparative road tests. | 7th Feb 1929 | Box 121 \ 2 scan0095 | |
| General performance report on the Solex double choke carburetter fitted to a 12-EX chassis. | 7th Feb 1929 | Box 121 \ 2 scan0096 | |
| Comparative test report on the performance of a Rolls Royce carburetter versus a Solex carburetter. | 7th Feb 1929 | Box 121 \ 2 scan0097 | |
| Comparison of R.R. and Solex carburettor performance during hill climb tests. | 7th Feb 1929 | Box 121 \ 2 scan0098 | |
| Comparative petrol consumption tests between a standard R.R. and a Solex carburettor. | 5th Feb 1929 | Box 121 \ 2 scan0099 | |
| Graph comparing the acceleration performance of a Phantom (12EX) with a Solex and an RR carburetter. | 5th Feb 1929 | Box 121 \ 2 scan0100 | |
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