| Description | Date | Identifier | |
| The despatch of contact breaker levers and screws for inspection. | 10th Jan 1927 | Box 35 \ 6 scan 230 | |
| Performance of battery ignition contact maker tungsten points compared to Delco Remy parts. | 10th Jan 1927 | Box 35 \ 6 scan 231 | |
| Instructions regarding improvements to a battery ignition contact breaker using an experimental cam. | 13th Jan 1927 | Box 35 \ 6 scan 232 | |
| Instruction comparing R.R. and Delco-Remy contact breakers regarding earthing and insulation. | 29th Jun 1920 | Box 35 \ 6 scan 233 | |
| Battery ignition contact points, comparing the performance of platinum and tungsten with periodic current reversal. | 19th Jan 1927 | Box 35 \ 6 scan 234 | |
| Testing conditions and the sending of points for comparative inspection. | 19th Jan 1927 | Box 35 \ 6 scan 235 | |
| Suggestions for improving the life of battery ignition contact points for Phantom, 20 HP, & Silver Ghost models. | 25th Jan 1927 | Box 35 \ 6 scan 236 | |
| Component design improvements, material considerations, and spare parts availability. | 27th Jan 1927 | Box 35 \ 6 scan 237 | |
| Technical memo detailing the ongoing testing and development of battery ignition components. | 27th Jan 1927 | Box 35 \ 6 scan 238 | |
| Design proposals for lever and spring mechanisms, including the use of tungsten and current reversal. | 27th Jan 1927 | Box 35 \ 6 scan 239 | |
| Design of contact makers for battery ignition and exhaust valves, comparing Delco and Bosch designs. | 31th Jan 1927 | Box 35 \ 6 scan 240 | |
| With diagrams discussing design improvements for a spring finger pivot and tungsten ignition points. | 28th Jan 1927 | Box 35 \ 6 scan 241 | |
| Experimental mounting for ignition contact points in a distributor. | 28th Jan 1927 | Box 35 \ 6 scan 242 | |
| Extract from a letter by Mr. Minchin of Peto & Radford regarding a preference for platinum points over tungsten ones. | 1st Feb 1927 | Box 35 \ 6 scan 243 | |
| New car trial feedback, parts stock management for upcoming improvements, and specific changes to 20 HP and electrical components. | 4th Feb 1927 | Box 35 \ 6 scan 244 | |
| Letter addressing an issue with the doming on tungsten points and suggesting a modification. | 7th Feb 1927 | Box 35 \ 6 scan 245 | |
| Letter from Peto & Radford regarding tungsten points. | 8th Feb 1927 | Box 35 \ 6 scan 246 | |
| Comparing the lifespan and performance of different magneto and battery ignition contact points. | 16th Feb 1927 | Box 35 \ 6 scan 247 | |
| Decision to use tungsten for battery ignition contact points. | 24th Feb 1927 | Box 35 \ 6 scan 248 | |
| Battery ignition, focusing on the life, design, and interchangeability of contact breaker points. | 23th Feb 1927 | Box 35 \ 6 scan 249 | |
| The production cost for Tungsten points versus Platinum points for standard battery ignition. | 3rd Mar 1927 | Box 35 \ 6 scan 250 | |
| Standardisation of tungsten points for battery ignition contact breakers. | 4th Mar 1927 | Box 35 \ 6 scan 251 | |
| Ignition system design, focusing on optimizing current at break and condenser capacity for platinum point life. | 12th Mar 1927 | Box 35 \ 6 scan 252 | |
| The standardisation of tungsten battery ignition contact points. | 4th Mar 1927 | Box 35 \ 6 scan 253 | |
| Technical note on the maintenance and alignment of battery ignition contact points. | 2nd Mar 1927 | Box 35 \ 6 scan 254 | |
| Standardisation of tungsten points pending the results of a 10,000-mile test. | 5th Mar 1927 | Box 35 \ 6 scan 255 | |
| The potential standardization of tungsten contact points to replace platinum points following a 10,000-mile test. | 5th Mar 1927 | Box 35 \ 6 scan 256 | |
| Comparing the costs of Iridio Platinum and Tungsten contact points for K. Series production. | 8th Mar 1927 | Box 35 \ 6 scan 257 | |
| Extract from Mr. Minchin's letter comparing the performance of tungsten and platinum points. | 9th Mar 1927 | Box 35 \ 6 scan 258 | |
| Manufacturing method of tungsten points and questioning a supplier. | 16th Mar 1927 | Box 35 \ 6 scan 259 | |
| Communication regarding the quality of tungsten points supplied by W.H. Reynolds & Co. | 21th Mar 1927 | Box 35 \ 6 scan 260 | |
| Replacing platinum battery ignition contact points with tungsten points on 12-EX. | 23th Mar 1927 | Box 35 \ 6 scan 261 | |
| Extract from a letter regarding a tail lamp indicator and tungsten points. | 22th Apr 1927 | Box 35 \ 6 scan 262 | |
| Pressure on battery ignition contact points and expressing dissatisfaction with progress on the unit. | 29th Apr 1927 | Box 35 \ 6 scan 263 | |
| Electrical experimental record sheet for mileage testing large diameter tungsten points. | 19th Apr 1926 | Box 35 \ 6 scan 264 | |
| Letter regarding the removal and return of battery ignition contact points after a specified mileage. | 2nd May 1927 | Box 35 \ 6 scan 265 | |
| Slow progress and failures of battery ignition systems on Phantom and 20HP models. | 3rd May 1927 | Box 35 \ 6 scan 266 | |
| 20 HP car's battery ignition fault, which was traced to water on the plugs. | 6th May 1927 | Box 35 \ 6 scan 267 | |
| 10,000-mile test of tungsten battery ignition points on chassis 10-G3 in France, comparing performance to platinum points. | 6th May 1927 | Box 35 \ 6 scan 268 | |
| Performance and potential standardization of tungsten contact points versus platinum points. | 6th May 1927 | Box 35 \ 6 scan 269 | |
| The operational challenges and considerations for tungsten points in distributors. | 14th May 1927 | Box 35 \ 6 scan 270 | |
| Requesting an experiment with tungsten points for a scrubbing action in a make and break system, as desired by Mr. Royce. | 14th May 1927 | Box 35 \ 6 scan 271 | |
| Outlining suggestions and testing conditions for improving battery ignition tungsten points. | 16th May 1927 | Box 35 \ 6 scan 272 | |
| Instructions for fitting and modifying the doming of tungsten points on battery ignition contact breaker levers. | 17th May 1927 | Box 35 \ 6 scan 273 | |
| List of suggestions for the improvement of operation of platinum or tungsten ignition contact points. | 18th May 1927 | Box 35 \ 6 scan 274 | |
| Progress report on experiments with various automotive electrical ignition components. | 18th May 1927 | Box 35 \ 6 scan 275 | |
| Progress report on a series of experiments concerning engine ignition components. | 19th May 1927 | Box 35 \ 6 scan 276 | |
| 10,000 mile bench ignition contact point experiments. | 19th May 1927 | Box 35 \ 6 scan 277 | |
| 10,000-mile bench ignition contact point experiments comparing Iridio-Platinum and Tungsten materials. | 19th May 1927 | Box 35 \ 6 scan 278 | |
| Experimental record sheet for large diameter (LD) tungsten points fitted to a vehicle. | 9th Oct 1925 | Box 35 \ 6 scan 279 | |
| Experimental record sheet for large diameter tungsten points, tracking mileage and condition. | 5th Nov 1926 | Box 35 \ 6 scan 280 | |
| Battery ignition system design featuring scrubbing contacts, a flexible spring, and a damping mechanism. | 4th Jun 1927 | Box 35 \ 6 scan 281 | |
| Requesting two special battery ignition contact breaker levers be sent to suppliers for fitting with new points. | 8th Jun 1927 | Box 35 \ 6 scan 282 | |
| Improvements to the battery ignition contact maker, including design alterations and wiring suggestions. | 10th Jun 1927 | Box 35 \ 6 scan 283 | |
| The slow progress in improving the life of tungsten contact points for battery ignition systems. | 18th Aug 1927 | Box 35 \ 6 scan 284 | |
| The supply and modification of battery ignition contact points with platinum and tungsten. | 20th Jun 1927 | Box 35 \ 6 scan 285 | |
| Experimental testing of battery ignition tungsten points. | 21th Jun 1927 | Box 35 \ 6 scan 286 | |
| Specifications for doming of platinum and tungsten battery ignition contact screw points. | 21th Jun 1927 | Box 35 \ 6 scan 287 | |
| 10,000-mile bench tests for battery ignition contact points, detailing tests on condenser values and periodic current reversal. | 5th Jul 1927 | Box 35 \ 6 scan 288 | |
| Experiments and tests conducted on ignition system components. | 7th May 1927 | Box 35 \ 6 scan 289 | |
| Experiments with doming on platinum and tungsten screw points to improve initial contact bedding. | 5th Jul 1927 | Box 35 \ 6 scan 290 | |
| The bedding of electrical contact points, discussing doming and the use of platinum. | 5th Jul 1927 | Box 35 \ 6 scan 291 | |
| Page discussing a component alteration involving platinum and sending samples for inspection. | 5th Jul 1927 | Box 35 \ 6 scan 292 | |
| Experimental record sheet tracking the performance of large diameter tungsten points. | 22th Jan 1926 | Box 35 \ 6 scan 293 | |
| Requesting a comparative report on battery ignition systems from competitors like Delco and Bosch. | 11th Jul 1927 | Box 35 \ 6 scan 294 | |
| Letter from Joseph Lucas Research Laboratories discussing contact breaker 'make' and 'break' periods and primary inductance. | 11th Jul 1927 | Box 35 \ 6 scan 295 | |
| The order of precedence for experimental tests on battery ignition contact points. | 14th Jul 1927 | Box 35 \ 6 scan 296 | |
| Component noise, delays, and progress on experimental testing for the Phantom model. | 5th Jul 1927 | Box 35 \ 6 scan 297 | |
| Requesting the supply of tungsten contact points, levers and screws for battery ignition experiments. | 18th Jul 1927 | Box 35 \ 6 scan 298 | |
| Parts request for 12 sets of tungsten contact breaker levers and screw points, listing the required drawing numbers and quantities. | 19th Jul 1927 | Box 35 \ 6 scan 299 | |
| Urgent request to have the remaining tungsten point ground flat for ignition rig tests. | 9th Aug 1927 | Box 35 \ 6 scan 300 | |
| Requesting the fitting of tungsten points to battery ignition contact breaker levers. | 11th Aug 1927 | Box 35 \ 6 scan 301 | |
| Request to obtain Tungsten and Platinum screw points for experimental purposes. | 16th Aug 1927 | Box 35 \ 6 scan 302 | |
| Order of operation for the production of completed battery ignition levers. | 17th Aug 1927 | Box 35 \ 6 scan 303 | |
| Further work on battery ignition contact breaker levers. | 17th Aug 1927 | Box 35 \ 6 scan 304 | |
| Experiments with battery ignition contact points, focusing on scrubbing action and various methods of bedding for tungsten points. | 26th Aug 1927 | Box 35 \ 6 scan 305 | |
| Experiments on distributor and contact breaker points, comparing different materials and systems. | 26th Aug 1927 | Box 35 \ 6 scan 306 | |
| Results of endurance tests on various ignition system components. | 26th Aug 1927 | Box 35 \ 6 scan 307 | |
| Ignition contact breaker point tests, comparing Delco-Remy and standard components. | 26th Aug 1927 | Box 35 \ 6 scan 308 | |
| Experiments comparing Delco-Remy and U.S.A. Bosch ignition systems. | 26th Aug 1927 | Box 35 \ 6 scan 309 | |
| Use of tungsten over platinum for battery ignition points and comparing American Bosch and Delco systems. | 29th Aug 1927 | Box 35 \ 6 scan 310 | |
| And comparing the performance of ignition contact points from different manufacturers and materials. | 31th Aug 1927 | Box 35 \ 6 scan 311 | |
| Standardisation of tungsten points over platinum and postponing the decision pending further testing. | 31th Aug 1927 | Box 35 \ 6 scan 312 | |
| Standardising tungsten ignition contact points and ceasing orders for platinum points. | 9th Sep 1927 | Box 35 \ 6 scan 313 | |
| Standardisation of tungsten contact points for battery ignition to replace platinum points. | 6th Sep 1927 | Box 35 \ 6 scan 314 | |
| Form for authorising the standardisation of chassis parts, specifically turnout contact forms for battery ignition. | 9th Sep 1927 | Box 35 \ 6 scan 315 | |
| Road test report on the performance and wear of tungsten contact points. | 6th Sep 1927 | Box 35 \ 6 scan 316 | |
| Clarifying the standardisation of tungsten ignition points for the 20 HP and 40/50 HP chassis. | 7th Sep 1927 | Box 35 \ 6 scan 317 | |
| Test results of tungsten ignition contact points and a related standardization sheet. | 9th Sep 1927 | Box 35 \ 6 scan 318 | |
| Test report comparing the performance of different tungsten contact points, including standard, U.S.A. Bosch, and Delco-Remy models. | 2nd Sep 1927 | Box 35 \ 6 scan 319 | |
| The performance of tungsten ignition contact points after a 3300-mile test and a request for a design modification. | 2nd Sep 1927 | Box 35 \ 6 scan 320 | |
| Results of experiments on ignition systems, specifically the scrubbing action of contacts. | 12th Sep 1927 | Box 35 \ 6 scan 321 | |
| Letter concerning the failure of American Bosch ignitions and the development of a new battery ignition system. | 12th Sep 1927 | Box 35 \ 6 scan 322 | |
| Page two of a letter signed by Maurice Olley regarding the use of a ballast. | 12th Sep 1927 | Box 35 \ 6 scan 323 | |
| Alternative designs for scrubbing points and a rocker spring related to the battery ignition system. | 13th Sep 1927 | Box 35 \ 6 scan 324 | |
| Experiments on battery ignition contact points and requesting a drawing of a thinner scrubbing arm. | 15th Sep 1927 | Box 35 \ 6 scan 325 | |
| Requesting parts to maintain progress on tungsten point experiments. | 16th Sep 1927 | Box 35 \ 6 scan 326 | |
| New drawings for battery ignition components, specifically scrubbing contacts and a contact arm spring. | 17th Sep 1927 | Box 35 \ 6 scan 327 | |
| Request to prepare a set of parts for a new ignition distributor scheme with a flexible contact point. | 22th Sep 1927 | Box 35 \ 6 scan 328 | |
| List of part changes and modifications, including new parts for a distributor and condenser assembly. | 22th Sep 1927 | Box 35 \ 6 scan 329 | |
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