| Description | Date | Identifier | |
| Graph comparing calorstat tests between Smith's 'H' Filling-Standard and the 'Packless Gland' type. | 27th Dec 1933 | Box 105 \ 1 scan0207 | |
| Analysis of the effect of altitude on the 'air temp. to boil' radiator figure. | 24th Mar 1934 | Box 105 \ 1 scan0208 | |
| Formula to calculate the air temperature required for boiling at a specific altitude. | 24th Mar 1934 | Box 105 \ 1 scan0209 | |
| Graph showing the variation of boiling point of water, air temperature, and relative air density with altitude. | 24th Mar 1934 | Box 105 \ 1 scan0210 | |
| Graph showing the sea level air temperatures required for boiling to occur at different altitudes. | 24th Mar 1934 | Box 105 \ 1 scan0211 | |
| Graph showing the variation of radiator boiling temperature figure with altitude. | 26th Sep 1934 | Box 105 \ 1 scan0212 | |
| List of the cooling system capacities for the Phantom II, 20/25 HP, and Bentley models. | 26th Sep 1934 | Box 105 \ 1 scan0213 | |
| Comparison table of specifications for the Proposed Wraith, Bentley Experimental, and 20/25 HP radiators. | 19th Mar 1935 | Box 105 \ 1 scan0214 | |
| Table of revised weights and dimensions for various types of matrices. | 16th Apr 1935 | Box 105 \ 1 scan0215 | |
| Purchase and potential standardisation of radiator matrices for the 20/25-HP chassis. | 4th Jun 1935 | Box 105 \ 1 scan0216 | |
| Supply and pricing of radiator matrices for 20/25-HP 'K2' & 'L2' series chassis. | 31th Jul 1935 | Box 105 \ 1 scan0217 | |
| Confirming an order for 200 radiator matrices for the 20/25-HP 'K2' series chassis. | 15th Aug 1935 | Box 105 \ 1 scan0218 | |
| Scheme to test spring-loaded radiator shutters on a 20/25 car to address rattling issues. | 16th Aug 1935 | Box 105 \ 1 scan0219 | |
| Standardisation of the 20/25 HP chassis radiator matrices. | 16th Aug 1935 | Box 105 \ 1 scan0220 | |
| Pricing and supply of 20/25-HP radiator matrixes. | 2nd Dec 1935 | Box 105 \ 1 scan0221 | |
| Suggestions for cost reductions in the manufacture of the 20/25 HP chassis radiator. | 5th Dec 1935 | Box 105 \ 1 scan0222 | |
| Cost reduction proposals for the 20/25 Chassis radiator and shutters. | 12th Dec 1935 | Box 105 \ 1 scan0223 | |
| List of parts affected by the introduction of the 58m/m Marston Mark V Matrix for the 20/25 HP Chassis radiator. | 20th Dec 1935 | Box 105 \ 1 scan0224 | |
| List of parts affected by the introduction of the 58m/m Marston Mark V Matrix for the 20/25 HP Chassis radiator. | 20th Dec 1935 | Box 105 \ 1 scan0225 | |
| List of critical atmospheric temperatures for various engine and radiator configurations for 20/25 and Bentley models. | 23th Dec 1935 | Box 105 \ 1 scan0226 | |
| Recommendations for the final 20/25 HP radiator design. | 23th Dec 1935 | Box 105 \ 1 scan0227 | |
| The radiator matrix for the 20/25-HP Chassis 'L2' Series, including supplier orders and potential scrap. | 1st Jan 1936 | Box 105 \ 1 scan0228 | |
| Request for the status of production cards issued for parts of the 20/25-HP Chassis '12' Series. | 1st Jan 1936 | Box 105 \ 1 scan0229 | |
| The production status of various parts for the 20/25 HP Chassis, L.2. Series. | 6th Jan 1936 | Box 105 \ 1 scan0230 | |
| Standardisation of the radiator matrix for the 20/30 HP chassis. | 9th Jan 1936 | Box 105 \ 1 scan0231 | |
| Instructions regarding fitting unbalanced radiator shutters to the 25/30 chassis, similar to the Phantom III and Bentley models. | 9th Jan 1936 | Box 105 \ 1 scan0232 | |
| The pricing and stock position for radiators and their components for the 25/30-HP 'L2' Series chassis. | 13th Jan 1936 | Box 105 \ 1 scan0233 | |
| Status update on the production of various parts including Side Bonnet Angles and Tunnel Tubes, and radiator delivery schedules. | 13th Jan 1936 | Box 105 \ 1 scan0234 | |
| Cost-saving modification to the 25/30 HP Chassis radiator matrix, pending experimental testing. | 14th Jan 1936 | Box 105 \ 1 scan0235 | |
| Estimated critical atmospheric temperatures for 20/25 and Bentley models with different engine and radiator configurations. | 15th Jan 1936 | Box 105 \ 1 scan0236 | |
| New brake pedal stop for the Phantom III servo, referencing schedule N.Sch.4721. | 15th Jan 1936 | Box 105 \ 1 scan0237 | |
| Radiator matrix materials, corrosion, and the results of a discussion with Marstons. | 17th Jan 1936 | Box 105 \ 1 scan0238 | |
| Recommending a cost and weight-saving change to the Mark V radiator on the 20/25 model. | 17th Jan 1936 | Box 105 \ 1 scan0239 | |
| The design and preparation of a 25-30 radiator with sheet metal sideplates and unbalanced shutters for a 10,000-mile test. | 17th Jan 1936 | Box 105 \ 1 scan0240 | |
| Radiator design changes for the 20/30 HP 'L2' series chassis to achieve cost savings. | 29th Jan 1936 | Box 105 \ 1 scan0241 | |
| The testing and introduction of modified radiators for the 25/30 HP chassis. | 31th Jan 1936 | Box 105 \ 1 scan0242 | |
| Design changes for the 25-30 Radiator, focusing on weight and cost reduction. | 31th Jan 1936 | Box 105 \ 1 scan0243 | |
| Proposing a 10,000-mile and bumper test for a 25/30 HP chassis radiator. | 3rd Feb 1936 | Box 105 \ 1 scan0244 | |
| The investigation of boiling in Large Bore 20/25 models due to radiator shutters not opening at high speeds. | 6th Feb 1936 | Box 105 \ 1 scan0245 | |
| Recommendation on radiator shutter arrangement and calorstat spring design for the new 20/25 radiator. | 6th Feb 1936 | Box 105 \ 1 scan0246 | |
| Road test results for the 20/25 HP Calorstat on different engine types and configurations. | 6th Feb 1936 | Box 105 \ 1 scan0247 | |
| Fitting of flexibly bladed fans to Bentley and 20/25 cars. | 24th Feb 1936 | Box 105 \ 1 scan0248 | |
| Increased chassis production and a proposed change of radiator matrix for the 25/30-HP 'M2' Series chassis. | 12th Mar 1936 | Box 105 \ 1 scan0249 | |
| Radiator shutters on car 22-G-V not opening correctly at high speeds due to an overlap issue. | 21th Mar 1936 | Box 105 \ 1 scan0250 | |
| Confirming the matrix type for a new 25/30 radiator and the status of the Mark VI matrix test. | 23th Mar 1936 | Box 105 \ 1 scan0251 | |
| Need to fit a thermometer pocket to a Phantom III pump cover for radiator cooling tests at Brooklands. | 24th Mar 1936 | Box 105 \ 1 scan0252 | |
| Tests concerning the non-opening of 25/30 HP radiator shutters at high speeds. | 30th Mar 1936 | Box 105 \ 1 scan0253 | |
| Tabulated test results on the effect of wind pressure on shutter openings for 25/30 HP cars. | 30th Mar 1936 | Box 105 \ 1 scan0254 | |
| Conclusions and summary regarding radiator shutter overlap and performance issues. | 30th Mar 1936 | Box 105 \ 1 scan0255 | |
| Order for 50 sets of Radiator Matrix for the 25/30-HP Chassis, discussing the cost implications of using cast side plates versus pressed side plates. | 7th Apr 1936 | Box 105 \ 1 scan0256 | |
| Ordering 50 sets of radiator matrices for the 25/30-HP chassis, comparing cast versus pressed side plates. | 7th Apr 1936 | Box 105 \ 1 scan0257 | |
| New radiator design for the 25/30 HP model. | 12th May 1936 | Box 105 \ 1 scan0258 | |
| Modifications and testing of the 25/30 HP radiator. | 3rd Jun 1936 | Box 105 \ 1 scan0259 | |
| Modifications to a 25/30 HP radiator and a request for a standardisation sheet. | 3rd Jun 1936 | Box 105 \ 1 scan0260 | |
| 25/30-HP chassis radiators, proposing a cost-saving change from cast gunmetal to sheet metal plates. | 3rd Jun 1936 | Box 105 \ 1 scan0261 | |
| Delay in radiator testing for the 20/25 HP big bore engine due to weather conditions. | 4th Jun 1936 | Box 105 \ 1 scan0262 | |
| Cost comparison and recommendation to change the radiator filler cap for the 25/30 HP and Phantom III chassis. | 5th Jun 1936 | Box 105 \ 1 scan0263 | |
| Issuing a standardisation sheet for 25/30 HP chassis radiator sheet metal side plates. | 8th Jun 1936 | Box 105 \ 1 scan0264 | |
| Standardisation sheet concerning the water connection from the engine to the radiator. | 19th Jun 1936 | Box 105 \ 1 scan0265 | |
| Inquiring about a delayed standardisation sheet for the 25/30 HP radiator's sheet metal side plates, with a handwritten response. | 3rd Jul 1936 | Box 105 \ 1 scan0266 | |
| Proposal to replace rubber hose and Dermatine water joints with Klingerite and Leyland 'FR' hose on various models. | 6th Jul 1936 | Box 105 \ 1 scan0267 | |
| Standardisation of radiator parts to save manufacturing costs, improve cooling and reduce weight. | 17th Jun 1936 | Box 105 \ 1 scan0268 | |
| Cost analysis document for extra production on the 'M' Series chassis, calculating net savings between old and new parts. | 29th Jun 1936 | Box 105 \ 1 scan0269 | |
| Instruction to incorporate a spring modification in the calorstat for 'M' series 25/30 HP radiators and apply it retrospectively. | 10th Sep 1936 | Box 105 \ 1 scan0270 | |
| Standardisation of parts for a water connection from engine to radiator, using rubber hose and clips instead of a metal pipe. | 23th Sep 1936 | Box 105 \ 1 scan0271 | |
| Cost estimate for extra Jigs, Tools and Equipment and production timeline for the first 'N' series chassis. | 19th Sep 1936 | Box 105 \ 1 scan0272 | |
| Testing a 30-HP radiator for leaks following a complaint from the Cricklewood Depot. | 8th Oct 1936 | Box 105 \ 1 scan0273 | |
| Cost and production implications of altering a radiator component for the 25/30 HP chassis. | 10th Dec 1936 | Box 105 \ 1 scan0274 | |
| Design criticisms and proposing cost reductions for the Wraith radiator. | 15th Feb 1937 | Box 105 \ 1 scan0275 | |
| Design changes and construction features for the 'Wraith' model radiator, aiming for cost reduction. | 19th Jan 1937 | Box 105 \ 1 scan0276 | |
| Design specifications for a radiator assembly and associated components. | 31th May 1937 | Box 105 \ 1 scan0277 | |
| Lending a Bentley shell shaping block and other radiator parts to an external supplier. | 31th May 1937 | Box 105 \ 1 scan0278 | |
| Standardisation of water connection rubber hoses and joint washers for the 25/30 HP model. | 10th May 1937 | Box 105 \ 1 scan0279 | |
| Tool costs for the 'S'2 Series chassis production. | 20th Aug 1937 | Box 105 \ 1 scan0280 | |
| Standardisation of a radiator matrix for the 25/30 HP model to save weight and cost. | 20th Aug 1937 | Box 105 \ 1 scan0281 | |
| Production note regarding zero extra tool costs for the 'S2' Series chassis. | 20th Aug 1937 | Box 105 \ 1 scan0282 | |
| Design of the steering column and the material for the instrument board for the 'India' model. | 9th Apr 1925 | Box 105 \ 2 scan0001 | |
| The 20 HP model's scuttle and dash isolation, specifically regarding instrument board brackets. | 15th Jun 1925 | Box 105 \ 2 scan0002 | |
| The supply of extra framed instruments for Captain Burt. | 1st Jul 1925 | Box 105 \ 2 scan0003 | |
| Instruments, instrument board, and petrol gauge design for Phantom and India models. | 16th Mar 1926 | Box 105 \ 2 scan0004 | |
| Record of agreement on the standardisation of coachwork features. | 16th Jul 1926 | Box 105 \ 2 scan0005 | |
| Standardisation document for transposing the ammeter and thermometer on 20 HP and 40/50 HP chassis. | 14th Jul 1926 | Box 105 \ 2 scan0006 | |
| Status of new grouped instruments for 40/50 and 20 HP models. | 14th Jul 1927 | Box 105 \ 2 scan0007 | |
| Internal memorandum about redesigning the instrument board for better appearance and value, comparing it to competitors. | 11th Apr 1928 | Box 105 \ 2 scan0008 | |
| Continued memo discussing cost to the customer and selling only standard equipment. | 18th Jun 1928 | Box 105 \ 2 scan0009 | |
| Telegram requesting a framed patch of instruments for Mr Royce's Twenty. | 18th Jun 1928 | Box 105 \ 2 scan0010 | |
| Urgent internal memo regarding the sourcing of a set of framed instruments for Mr. Royce's car. | 6th Jul 1928 | Box 105 \ 2 scan0011 | |
| Telegram received by telephone concerning the supply of instrument parts. | 9th Jul 1928 | Box 105 \ 2 scan0012 | |
| Correspondence regarding the supply and fitting of a framed instrument patch. | 9th Jul 1928 | Box 105 \ 2 scan0013 | |
| Short typed message regarding the supply of an instrument patch set. | 12th Jul 1928 | Box 105 \ 2 scan0014 | |
| Dispatch of a framed patch of instruments to Barkers and speedometer calibration for chassis 12-G-4. | 12th Jul 1928 | Box 105 \ 2 scan0015 | |
| Modifications to the cast dashboard for the INDIA 3 car to accommodate a framed instrument panel. | 18th Mar 1928 | Box 105 \ 2 scan0016 | |
| Modification of an instrument patch and speedometer for Mr. Royce's car and two other India 4 chassis. | 17th Jul 1928 | Box 105 \ 2 scan0017 | |
| Speedometers and modifications for instrument boards on models 14-G-4 and 16-G-4. | 26th Jul 1928 | Box 105 \ 2 scan0018 | |
| Instrument boards for India 3, regarding the suitability of speedometers and a delay for modifications to include a K.S. gauge and green lamp. | 4th Sep 1928 | Box 105 \ 2 scan0019 | |
| Instrument panel specifications for various experimental car models, including background colour and other features. | 1st Dec 1928 | Box 105 \ 2 scan0020 | |
| Telegram received by telephone regarding specifications for tyres and an instrument. | 7th Dec 1926 | Box 105 \ 2 scan0021 | |
| Design changes and feedback for a Hooper Sedanca, referencing Mr. Royce's requests. | 18th Dec 1928 | Box 105 \ 2 scan0022 | |
| Telegram received by telephone regarding car specifications. | 7th Dec 1926 | Box 105 \ 2 scan0023 | |
| Customer feedback on a 20 HP car, with suggestions on pricing, frame design, instruments, and weight. | 21th Jan 1929 | Box 105 \ 2 scan0024 | |
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