| Description | Date | Identifier | |
| Letter from Cadillac Motor Car Company to E. W. Hives regarding propeller shaft assemblies. | 21th Oct 1931 | Box 170 \ 2 img109 | |
| Letter discussing formulas and specifications for the critical speeds of drive shaft tubes. | 19th Oct 1931 | Box 170 \ 2 img110 | |
| Letter to Cadillac seeking information on induction pipe silencing, shock absorbers, and exhaust valve practices. | 31th Oct 1931 | Box 170 \ 2 img111 | |
| Letter to Cadillac discussing test results for propeller shafts, road springs, and shock absorbers. | 2nd Nov 1931 | Box 170 \ 2 img112 | |
| Letter discussing chassis vibration test results and inquiring about the use of aluminium drums with cast iron linings in the US. | 4th Nov 1931 | Box 170 \ 2 img113 | |
| Letter from Cadillac Motor Car Company requesting information on trick white metals under the Hall patents. | 4th Nov 1931 | Box 170 \ 2 img114 | |
| Letter to Cadillac discussing a US visit to research American synchro-mesh and silent gearbox technology. | 9th Nov 1931 | Box 170 \ 2 img115 | |
| Letter to Cadillac Motor Car Co. inquiring about the use of dynamic balancing machines. | 12th Nov 1931 | Box 170 \ 2 img116 | |
| Letter to Cadillac Motor Car Co. discussing experiences with Hall's and Kelmet bearing alloys. | 10th Nov 1931 | Box 170 \ 2 img117 | |
| Letter discussing a trip to the U.S.A. to research dynamic balancing machines for car parts. | 16th Nov 1931 | Box 170 \ 2 img118 | |
| Letter to Cadillac Motor Car Co. inquiring about improvements to Bijur drip plugs, which are found to be blocked after endurance tests. | 19th Nov 1931 | Box 170 \ 2 img119 | |
| Letter from Maurice Olley of Cadillac regarding bearing alloys, crankshaft balancing and suspension damping. | 1st Dec 1931 | Box 170 \ 2 img120 | |
| Letter to M. Olley of Cadillac discussing rear-engined cars, specifically the Burney and a Beverley Barnes straight 8 power unit. | 12th Dec 1931 | Box 170 \ 2 img121 | |
| Passenger comfort, noise levels, and speed performance of a vehicle. | 12th Dec 1931 | Box 170 \ 2 img122 | |
| Advantages and disadvantages of a rear-engined car, its potential market success, and competitor reactions. | 2nd Dec 1931 | Box 170 \ 2 img123 | |
| Cablegram from Detroit advising that Robotham Industry will probably start buying from January onwards. | 16th Dec 1931 | Box 170 \ 2 img124 | |
| Letter to M. Olley of Cadillac Motor Car Co. regarding travel arrangements to Detroit. | 13th Jan 1932 | Box 170 \ 2 img125 | |
| Letter to Cadillac Motor Co. regarding the dispatch of aluminium alloy test pieces. | 15th Feb 1933 | Box 170 \ 2 img126 | |
| Sending 8 cast bars of two different casting alloys (53 and R.R. 50) to the laboratory. | 13th Feb 1932 | Box 170 \ 2 img127 | |
| Eight cylinder head alloy test pieces to be sent to Cadillac Motor Co., Detroit. | 15th Feb 1932 | Box 170 \ 2 img128 | |
| Letter to M. Olley of Cadillac Motor Car Co. regarding a sketch of a joggling rig and the ordering of a carburetter. | 24th Feb 1932 | Box 170 \ 2 img129 | |
| Letter to Mr. Olley of Cadillac Motor Co. regarding a drawing of the Phantom radiator cap. | 29th Feb 1932 | Box 170 \ 2 img130 | |
| Letter from Cadillac discussing front axle geometry, radiator caps, and testing rigs. | 15th Mar 1932 | Box 170 \ 2 img131 | |
| Conclusion on an arrangement with and without a shimmy shackle. | 15th Mar 1932 | Box 170 \ 2 img132 | |
| Letter from Cadillac Motor Car Company to Rolls Royce regarding the performance of AC fuel pumps in Germany. | 7th Feb 1933 | Box 170 \ 2 img133 | |
| Confirming correspondence has been returned and a thank you letter has been sent to Cy. | 21th Mar 1933 | Box 170 \ 2 img134 | |
| Letter from Cadillac Motor Car Company regarding a 12 cyl. fan, needle bearing joints, and shock absorbers. | 4th Mar 1933 | Box 170 \ 2 img135 | |
| Letter discussing the performance of inertia shock absorbers and referencing an attached generator output chart. | 3rd Mar 1933 | Box 170 \ 2 img136 | |
| Hand-drawn diagram illustrating the function of a lead weight within an oil-filled damper chamber. | 3rd Mar 1933 | Box 170 \ 2 img137 | |
| Performance curves for a 93H D generator showing limits when cold and hot. | 16th Jan 1931 | Box 170 \ 2 img138 | |
| Letter discussing André Dubonnet's cars, suspension device, and patent status. | 16th Jan 1931 | Box 170 \ 2 img139 | |
| From Maurice Olley regarding work progress, with various technical calculations concerning weight and efficiency. | 31th Mar 1933 | Box 170 \ 2 img140 | |
| Letter from Delco Products Corporation confirming the shipment of experimental shock absorbers. | 31th Mar 1933 | Box 170 \ 2 img141 | |
| Letter to M. Olley at Cadillac regarding the automotive industry, a new Bentley, and streamlining challenges. | 10th May 1933 | Box 170 \ 2 img142 | |
| Letter discussing royalties, shock absorbers, power output, fuel quality, and competitor analysis of American cars. | 6th Jun 1933 | Box 170 \ 2 img143 | |
| Letter from Delco Products Corporation to Cadillac providing test machine connecting rod length information. | 6th Jun 1933 | Box 170 \ 2 img144 | |
| Letter to Cadillac discussing bringing a Bentley to America and critiquing an Essex Terraplane. | 15th Jun 1938 | Box 170 \ 2 img145 | |
| Diagram for a Torsional Load Indicator mechanism. | 15th Jun 1938 | Box 170 \ 2 img146 | |
| Excerpt from a letter discussing the performance and cornering ability of a 20/25 HP car. | 17th Jun 1933 | Box 170 \ 2 img147 | |
| Value of unofficial correspondence with Mr. Olley regarding General Motors' advanced development and the impact of economic policies on American car imports. | 17th Jun 1933 | Box 170 \ 2 img148 | |
| Letter discussing the performance and market for competing American cars and their challenge to the luxury car segment. | 17th Jun 1933 | Box 170 \ 2 img149 | |
| Car design principles, comparing large versus small cars, and the merits of rigid frame and body construction. | 17th Jun 1933 | Box 170 \ 2 img150 | |
| Comparative analysis of competitor vehicle chassis rigidity, engine mounting, and resulting road performance issues. | 17th Jun 1933 | Box 170 \ 2 img151 | |
| Automotive design trends, aerodynamics, and passenger placement. | 17th Jun 1933 | Box 170 \ 2 img152 | |
| Rear-engine car design, weight distribution, and handling characteristics. | 17th Jun 1933 | Box 170 \ 2 img153 | |
| Technical note discussing potential improvements in car design including heating, brakes, and weight reduction. | 17th Jun 1933 | Box 170 \ 2 img154 | |
| Rear engines, streamlining, and the importance of the power-to-weight ratio for acceleration in city traffic. | 17th Jun 1933 | Box 170 \ 2 img155 | |
| Superchargers, shock absorbers, and the influence of various road conditions on ride quality and suspension. | 17th Jun 1933 | Box 170 \ 2 img156 | |
| Vehicle suspension dynamics, ride control, and the performance of shock absorbers on long-wave road undulations. | 17th Jun 1933 | Box 170 \ 2 img157 | |
| Letter from Maurice Olley discussing design reactions, workload, and specific engineering topics. | 17th Jun 1933 | Box 170 \ 2 img158 | |
| Market analysis comparing American small cars with larger, more expensive models, discussing their respective merits and market positions. | 17th Jun 1933 | Box 170 \ 2 img159 | |
| Analysis of competitor vehicle body and engine mounting techniques and their effects on noise and vibration. | 17th Jun 1933 | Box 170 \ 2 img160 | |
| Future car design principles, including rear engines, wheelbase, weight distribution, and aerodynamics. | 17th Jun 1933 | Box 170 \ 2 img161 | |
| Technical report discussing potential improvements in engines, brakes, streamlining, and shock absorbers. | 17th Jun 1933 | Box 170 \ 2 img162 | |
| Letter from Maurice Olley discussing road conditions, ride comfort, and shock absorber design. | 20th Jun 1933 | Box 170 \ 2 img163 | |
| Short typed memo acknowledging unofficial correspondence and the value of its contents. | 20th Jun 1933 | Box 170 \ 2 img164 | |
| Letter to Cadillac discussing the Motor Show, Bentley camshaft troubles with Textolite gears, and visits from American companies. | 7th Aug 1933 | Box 170 \ 2 img165 | |
| Letter to M. Olley of Cadillac discussing an upcoming US visit, supercharger research, and gearbox developments. | 27th Sep 1933 | Box 170 \ 2 img166 | |
| Letter discussing developments in engine design, camshafts, suspension, and wind tunnel tests. | 22th Sep 1933 | Box 170 \ 2 img167 | |
| Letter from Maurice Olley of Cadillac to W. A. Robotham of Rolls-Royce arranging meetings for visiting staff. | 22th Sep 1933 | Box 170 \ 2 img168 | |
| Letter from Cadillac Motor Car Company regarding the timing of a visit. | 10th Oct 1935 | Box 170 \ 2 img169 | |
| Letter to Cadillac discussing the testing and performance of aluminium pistons and the R.R.53 alloy. | 25th Oct 1933 | Box 170 \ 2 img170 | |
| Piston specifications, a potential order for Aerolite pistons, and a query on Ford's cyanide hardening process. | 3rd Nov 1933 | Box 170 \ 2 img171 | |
| Letter from the Cadillac Motor Car Company to W. A. Robotham thanking him for hospitality during a visit to Derby. | 3rd Nov 1933 | Box 170 \ 2 img172 | |
| Letter from Cadillac Motor Car Company proposing a car swap with Rolls Royce for evaluation. | 3rd Nov 1933 | Box 170 \ 2 img173 | |
| Despatch of a free scrap Aerolite piston to The Cadillac Motor Co. in Detroit. | 16th Nov 1933 | Box 170 \ 2 img174 | |
| Letter to Cadillac Motor Co. comparing the material specifications of Aerolite 122 and RR.53 alloys for pistons. | 16th Nov 1933 | Box 170 \ 2 img175 | |
| Piston failure, design choices, and market conditions in America. | 30th Nov 1933 | Box 170 \ 2 img176 | |
| Letter to Cadillac arranging a visit for an employee to observe American automotive production. | 30th Nov 1933 | Box 170 \ 2 img177 | |
| Letter to M. Olley of Cadillac discussing a surge in domestic car sales, factory extensions, and a planned visit for Mr. Coverely to the USA. | 2nd Dec 1933 | Box 170 \ 2 img178 | |
| Continuation of a letter discussing personnel movements, a potential car exchange, and left-hand drive chassis production. | 2nd Dec 1933 | Box 170 \ 2 img179 | |
| Letter to M. Olley of The Cadillac Motor Co. regarding a photograph and prints of a 3-litre Bentley engine induction port. | 8th Feb 1934 | Box 170 \ 2 img180 | |
| Letter to Cadillac in Detroit discussing vehicle handling, requesting specifications for a Buick, and information on valve spring steel for comparison. | 19th Apr 1934 | Box 170 \ 2 img181 | |
| Letter discussing springs made of straight carbon wire in Detroit and the arrival of the first La Salle in England. | 19th Apr 1934 | Box 170 \ 2 img182 | |
| Letter to the Cadillac Motor Car Co. discussing the performance of Aerolite pistons, including test results and planned modifications. | 3rd May 1934 | Box 170 \ 2 img183 | |
| Letter to Cadillac requesting an arrangement drawing for the new baby Buick and a catalogue for thermostats, with an update on Dubonnet suspension. | 7th May 1934 | Box 170 \ 2 img184 | |
| Page two of a letter with closing remarks to Mrs. Olley and family. | 7th May 1934 | Box 170 \ 2 img185 | |
| Comparison between 'Wishbone' and 'Dubonnet' independent suspension systems. | 3rd May 1934 | Box 170 \ 2 img186 | |
| Comparison of Dubonnet and wishbone suspension systems, detailing their respective features and drawbacks. | 3rd May 1934 | Box 170 \ 2 img187 | |
| List of features for a mechanical system, likely related to suspension or steering, numbered 4 to 7. | 24th May 1934 | Box 170 \ 2 img188 | |
| Letter to Cadillac regarding valve spring information, the delayed arrival of a Cadillac and an enquiry about a new Buick. | 24th May 1934 | Box 170 \ 2 img189 | |
| Inquiry to Cadillac regarding General Motors' practice of increasing main bearing diameters. | 29th May 1934 | Box 170 \ 2 img190 | |
| Letter to the Cadillac Motor Car Co. asking about Buick suspension specifications and front stabilisers. | 31th May 1934 | Box 170 \ 2 img191 | |
| Letter from the Cadillac Motor Car Company discussing rubber bushings and front roll stabilizers. | 12th Jun 1934 | Box 170 \ 2 img192 | |
| Letter to Cadillac regarding a synchromesh problem with the Bentley gearbox. | 31th Jul 1934 | Box 170 \ 2 img193 | |
| Letter to M. Olley of Cadillac regarding the difficult arrival of a Cadillac and issues with agents. | 31th Jul 1934 | Box 170 \ 2 img194 | |
| Letter discussing expectations for a Buick, a US heat wave, and features for a future Cadillac. | 31th Jul 1934 | Box 170 \ 2 img195 | |
| Letter from Cadillac Motor Car Company regarding the practice of stepped crank bearing diameters. | 7th Aug 1954 | Box 170 \ 2 img196 | |
| Letter from Cadillac Motor Car Company regarding Synchromesh clatter and potential cures. | 14th Aug 1934 | Box 170 \ 2 img197 | |
| Experiments with clutch disc fabrics, linings, and lubricants to resolve vibration issues. | 26th Aug 1934 | Box 170 \ 2 img198 | |
| Letter to M. Olley at Cadillac discussing synchromesh rattles, crankshaft bearings and comparing a Cadillac's performance to the Phantom II. | 26th Aug 1934 | Box 170 \ 2 img199 | |
| Typed letter providing feedback on a car's performance, handling, and wireless set installation. | 28th Aug 1934 | Box 170 \ 2 img200 | |
| Letter discussing feedback and performance comparison of a Cadillac motor car. | 28th Aug 1934 | Box 170 \ 2 img201 | |
| Performance and handling review of a vehicle, including feedback on the wireless set and comparisons to other models. | 28th Aug 1934 | Box 170 \ 2 img202 | |
| Letter to Cadillac inquiring about their experience with Lavine Steering Gear after seeing an advertisement. | 6th Sep 1934 | Box 170 \ 2 img203 | |
| Letter to M. Olley of Cadillac Motor Car Co. arranging to meet at the Bentley Stand. | 15th Oct 1934 | Box 170 \ 2 img204 | |
| Personal letter to M. Olley at Cadillac requesting parts and information. | 25th Oct 1934 | Box 170 \ 2 img205 | |
| Letter to the Cadillac Motor Car Co. requesting a right-hand steering system and mentioning a vehicle test report. | 7th Nov 1934 | Box 170 \ 2 img206 | |
| Test drive report detailing the car's steering, riding qualities, and handling on various roads in France. | 5th Nov 1934 | Box 170 \ 2 img207 | |
| Letter to the Cadillac Motor Car Co. inquiring about the advantages of American-style steering gears. | 19th Nov 1934 | Box 170 \ 2 img208 | |
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