| Description | Date | Identifier | |
| Issues with speedometer drive squares twisting off due to the load from mechanically driven screen wipers. | 14th May 1927 | Box 50 \ 4 Scan116 | |
| Letter to a speedometer company requesting a calibration update for new tyre specifications. | 18th May 1927 | Box 50 \ 4 Scan117 | |
| Letter from A.T. Speedometer Co. Ltd. regarding the results of tests on their speedometers and forwarding a new unit for testing. | 7th Jun 1927 | Box 50 \ 4 Scan118 | |
| Letter from A.T. Speedometer Co. Ltd. regarding the metal used for a 'System Cup' in their devices. | 7th Jun 1927 | Box 50 \ 4 Scan119 | |
| Letter to the A.T. Speedometer Co. discussing the performance testing of a modified speedometer under temperature variations. | 18th Jun 1927 | Box 50 \ 4 Scan120 | |
| Returning a speedometer and a revolution counter to the A.T. Speedometer Co. for modification. | 21th Jun 1927 | Box 50 \ 4 Scan121 | |
| Letter to A.T. Speedometer Co. regarding the urgent modification of a Revolution Counter and a Speedometer. | 21th Jun 1927 | Box 50 \ 4 Scan122 | |
| Letter from A.T. Speedometer Co. Ltd. confirming the dispatch of an experimental Speedometer and Revolution Counter. | 29th Jun 1927 | Box 50 \ 4 Scan123 | |
| Letter from A.T. Speedometer Co. Ltd. regarding a delay in completing the timing of two special instruments and their subsequent despatch. | 30th Jun 1927 | Box 50 \ 4 Scan124 | |
| Letter to A.T. Speedometer Co. arranging the collection of a Revolution Counter and Speedometer. | 30th Jun 1927 | Box 50 \ 4 Scan125 | |
| Request to modify an A.T. Speedometer so that its reading is not affected by temperature. | 11th Jul 1927 | Box 50 \ 4 Scan126 | |
| Temperature-related inaccuracies in A.T. speedometers and the recommendation to fit a modified version. | 13th Jul 1927 | Box 50 \ 4 Scan127 | |
| Graph comparing the percentage error of a standard 1926 A.T. speedometer and an improved July 1927 version against temperature rise. | 14th Jul 1927 | Box 50 \ 4 Scan128 | |
| Query regarding the readiness of new models and the status of associated instruments like clocks, dials, and speedometers. | 14th Jul 1927 | Box 50 \ 4 Scan129 | |
| Experimental work on A.T. speedometers, detailing a temperature-related fault that has since been resolved by the manufacturer. | 18th Jul 1927 | Box 50 \ 4 Scan130 | |
| The cost of work on speedometers by the A.T. Co. | 19th Jul 1927 | Box 50 \ 4 Scan131 | |
| Merits of different types of instrument dials, the layout of grouped instruments, and issues with the A.T. speedometer. | 1st Aug 1927 | Box 50 \ 4 Scan132 | |
| Fitting of framed instruments and querying the supply and design of specific dials and clocks. | 13th Aug 1927 | Box 50 \ 4 Scan133 | |
| Letter to the A.T. Speedometer Co. Ltd. regarding the change in reading of eddy-current speedometers with temperature and time. | 15th Aug 1927 | Box 50 \ 4 Scan134 | |
| Design and approval of grouped instruments, specifically clock dials. | 17th Aug 1927 | Box 50 \ 4 Scan135 | |
| Letter from a supplier discussing the long-term accuracy and stability of speedometer instruments. | 18th Aug 1927 | Box 50 \ 4 Scan136 | |
| Letter from A.T. Speedometer Co. Ltd. discussing the lifespan and permanency of magnets. | 18th Aug 1927 | Box 50 \ 4 Scan137 | |
| Suitability of different speed indicators and the preferred style for instrument dials, specifically cream porcelain with Arabic figures. | 19th Aug 1927 | Box 50 \ 4 Scan138 | |
| Tests on the A.T. eddy-current speedometer regarding reading changes due to temperature and magnet ageing. | 19th Aug 1927 | Box 50 \ 4 Scan139 | |
| Modification for an A.T. Speedometer to overcome temperature effects. | 19th Aug 1927 | Box 50 \ 4 Scan140 | |
| Arranging a test on an A.T. speedometer for changes in reading over time. | 22th Aug 1927 | Box 50 \ 4 Scan141 | |
| Testing and replacing an A.T. speedometer on chassis 12-EX. | 23th Aug 1927 | Box 50 \ 4 Scan142 | |
| Test results for an A.T. Speedometer removed from chassis 12-EX for laboratory testing. | 23th Aug 1927 | Box 50 \ 4 Scan143 | |
| Letter from A.T. Speedometer Co. Ltd. confirming the despatch of an experimental speedometer. | 27th Aug 1927 | Box 50 \ 4 Scan144 | |
| Letter to A.T. Speedometer Co. confirming a wire sent to urge the completion of an experimental speedometer. | 27th Aug 1927 | Box 50 \ 4 Scan145 | |
| Letter to A.T. Speedometer Co. Ltd. requesting the handover of experimental speedometer No. 16265. | 29th Aug 1927 | Box 50 \ 4 Scan146 | |
| Confirming receipt of a modified speedometer from the A.T. Speedometer Co. | 6th Sep 1927 | Box 50 \ 4 Scan147 | |
| Speedometer on a trials car reading 6% slow due to temperature error and recommending an updated duralumin cup. | 1st Sep 1927 | Box 50 \ 4 Scan148 | |
| Speedometer drive issue on chassis GSK-78. | 1st Sep 1927 | Box 50 \ 4 Scan149 | |
| Supply issue with new temperature compensating devices for speedometers from the A.T. Speedometer Company. | 17th Sep 1927 | Box 50 \ 4 Scan150 | |
| Test report for an A.T. speedometer removed from chassis 14-EX. | 17th Nov 1927 | Box 50 \ 4 Scan151 | |
| Test results for an A.T. Speedometer (14-EX) showing MPH readings at various temperatures. | 19th Nov 1927 | Box 50 \ 4 Scan152 | |
| Test results for an A.T. Speedometer (14-EX) showing M.P.H. readings at various temperatures. | 19th Nov 1927 | Box 50 \ 4 Scan153 | |
| The speeding up ratio of a Smith double drive for a speedometer and screen wiper in relation to the EAC.10 gearbox. | 1st Dec 1927 | Box 50 \ 4 Scan154 | |
| Inquiry to A.T. Speedometer Co. about the impact of reducing speedometer drive speed by 30%. | 8th Dec 1927 | Box 50 \ 4 Scan155 | |
| Proposal to reduce the speedometer drive speed and the decision to retain the current speed. | 13th Dec 1927 | Box 50 \ 4 Scan156 | |
| Testing of A.T. speedometers and requesting a standard instrument for calibration. | 16th Dec 1927 | Box 50 \ 4 Scan157 | |
| Parts to be ordered for the proposed 6 Alpine Phantom cars, including springs and rev counters. | 21th Dec 1927 | Box 50 \ 4 Scan158 | |
| Specification document for speedometers and rev counters, detailing calibration requirements and component specifics. | 22th Dec 1927 | Box 50 \ 4 Scan159 | |
| Information regarding A.T. speedometers ordered for a grouped instrument board. | 22th Dec 1927 | Box 50 \ 4 Scan160 | |
| The calibration of A.T. speedometers for the 40/50 HP chassis. | 22th Dec 1927 | Box 50 \ 4 Scan161 | |
| Order for a speedometer cable. | 28th Dec 1927 | Box 50 \ 4 Scan162 | |
| Comparing Jaeger and A.T. speedometers, citing noise and complexity issues with the former. | 27th Jan 1928 | Box 50 \ 4 Scan163 | |
| Test report for a Bleriot A.T. Speedometer. | 30th Jan 1928 | Box 50 \ 4 Scan164 | |
| Requesting to increase the length of speedometer cables for the sports car from 4' 10' to 5' 0'. | 1st Feb 1928 | Box 50 \ 4 Scan165 | |
| Request to examine and recalibrate a speedometer from chassis 16-EX to correct a temperature error and make it read 10% fast. | 24th Feb 1928 | Box 50 \ 4 Scan166 | |
| Confirmation on whether A.T. speedometers for 40/50 and 20 HP models are fitted with a full temperature compensating device. | 24th Feb 1928 | Box 50 \ 4 Scan167 | |
| The results of retesting an A.T. Speedometer and its performance issues. | 1st Mar 1928 | Box 50 \ 4 Scan168 | |
| Calibration and temperature error of a speedometer. | 1st Mar 1928 | Box 50 \ 4 Scan169 | |
| Speedometer accuracy adjustments and variations in tyre circumference figures. | 2nd Mar 1928 | Box 50 \ 4 Scan170 | |
| Faulty A.T. speedometer reading that is affected by temperature changes. | 2nd Mar 1928 | Box 50 \ 4 Scan171 | |
| Temperature error and performance of the A.T. Speedometer. | 5th Mar 1928 | Box 50 \ 4 Scan172 | |
| Progress and challenges of fitting temperature compensating devices into A.T. Speedometers. | 6th Mar 1928 | Box 50 \ 4 Scan173 | |
| Test report on the temperature effect and accuracy of an A.T. Speedometer. | 7th Mar 1928 | Box 50 \ 4 Scan174 | |
| Acceptable performance variation of A.T. speedometers with temperature changes. | 14th Mar 1928 | Box 50 \ 4 Scan175 | |
| Testing of an A.T. Speedometer, specifically its accuracy variations with temperature changes. | 15th Mar 1928 | Box 50 \ 4 Scan176 | |
| Specification sheet detailing speedometer speeds for 20 HP and Phantom chassis models based on axle ratio and tyre size. | 15th Mar 1928 | Box 50 \ 4 Scan177 | |
| Temperature compensation and accuracy tests on A.T. Speedometers. | 15th Mar 1928 | Box 50 \ 4 Scan178 | |
| Difficulties with the A.T. Speedometer's compensating device and the changeover between instruments for different HP models. | 15th Mar 1928 | Box 50 \ 4 Scan179 | |
| Requesting a 20 HP type A.T. speedometer for testing following tests on the 40/50 HP type. | 17th Mar 1928 | Box 50 \ 4 Scan180 | |
| Letter to the A.T. Speedometer Co. Ltd. detailing the results of tests on their speedometer instruments. | 17th Mar 1928 | Box 50 \ 4 Scan181 | |
| Letter discussing the performance and accuracy requirements for vehicle instruments at different temperatures and for a 20 HP chassis. | 17th Mar 1928 | Box 50 \ 4 Scan182 | |
| Graph showing the performance of Phantom eddy current speedometers against instrument temperature for various axle ratios. | 20th Mar 1928 | Box 50 \ 4 Scan183 | |
| Urgent internal order request for a clock, speedometer, and wiper for chassis 17-EX. | 20th Mar 1928 | Box 50 \ 4 Scan184 | |
| Test results for an A.T. Speedometer, recording MPH and revolutions per mile at different temperatures. | 20th Mar 1928 | Box 50 \ 4 Scan185 | |
| Letter from A.T. Speedometer Co. Ltd. regarding special tests on supplied instruments. | 21th Mar 1928 | Box 50 \ 4 Scan186 | |
| Speedometer drive gearing and test rig calibration for the 12-EX chassis. | 22th Mar 1928 | Box 50 \ 4 Scan187 | |
| The performance and recalibration of an A.T. Speedometer at various temperatures. | 24th Mar 1928 | Box 50 \ 4 Scan188 | |
| Performance graph for a Phantom's eddy current speedometer, plotting instrument reading against temperature for various axle ratios. | 24th May 1928 | Box 50 \ 4 Scan189 | |
| Letter from A.T. Speedometer Co. Ltd. discussing puzzling variations in instrument test results. | 4th Apr 1928 | Box 50 \ 4 Scan190 | |
| Test report on an A.T. Speedometer for a 20 HP type, noting a lack of temperature compensation. | 17th Apr 1928 | Box 50 \ 4 Scan191 | |
| Letter from A.T. Speedometer Co. Ltd. responding to test results for 40/50 hp speedometers, detailing their own findings on temperature variation. | 18th Apr 1928 | Box 50 \ 4 Scan192 | |
| Letter from A.T. Speedometer Co. Ltd. regarding the testing and development of instruments for a 20 hp chassis. | 18th Apr 1928 | Box 50 \ 4 Scan193 | |
| Correspondence and the further testing of A.T. speedometers. | 19th Apr 1928 | Box 50 \ 4 Scan194 | |
| Letter to A.T. Speedometer Co.Ltd. regarding discrepancies in speedometer test results. | 19th Apr 1928 | Box 50 \ 4 Scan195 | |
| The concluding page of a letter or report, with a note regarding readings taken at 600 r.p.m. | 20th Apr 1928 | Box 50 \ 4 Scan196 | |
| Letter from A.T. Speedometer Co. Ltd. regarding the testing of 40/50 hp speedometers. | 20th Apr 1928 | Box 50 \ 4 Scan197 | |
| Letter to A.T. Speedometer Co. Ltd. regarding puzzling test results for an instrument. | 3rd May 1928 | Box 50 \ 4 Scan198 | |
| The despatch of a speedometer to its makers for testing. | 2nd Jun 1928 | Box 50 \ 4 Scan199 | |
| Letter to The A.T. Speedometer Co. Ltd. detailing the results of tests conducted on a speedometer instrument. | 12th Jun 1928 | Box 50 \ 4 Scan200 | |
| Letter discussing the performance, testing, and manufacture of instruments, specifically a speedometer. | 13th Jun 1928 | Box 50 \ 4 Scan201 | |
| Test results for two speedometers, measuring M.P.H. and revolutions per mile at various temperatures. | 13th Jun 1928 | Box 50 \ 4 Scan202 | |
| Test results for speedometer number B.247.D.730, tested in a new box with a fan. | 14th Jun 1928 | Box 50 \ 4 Scan203 | |
| Speedometer to be sent to The A.T. Speedometer Co. Ltd. for testing. | 14th Jun 1928 | Box 50 \ 4 Scan204 | |
| Letter from A.T. Speedometer Co. Ltd. discussing test results and adjustments for speedometer No. B.247. | 18th Jun 1928 | Box 50 \ 4 Scan205 | |
| Forwarding an attached letter from the A.T. Speedometer Co. | 19th Jun 1928 | Box 50 \ 4 Scan206 | |
| Letter concerning a complaint about a sticking speedometer and the manufacturer's response after inspection. | 20th Jun 1928 | Box 50 \ 4 Scan207 | |
| Urgent request for a speedometer for an experimental 20 HP chassis being built for Mr. Royce. | 2nd Jul 1928 | Box 50 \ 4 Scan208 | |
| Letter confirming a telephone conversation to modify a speedometer for Mr. Royce's car. | 17th Jul 1928 | Box 50 \ 4 Scan209 | |
| Unpaid invoice from the A. T. Speedometer Co. Ltd. for a speedometer conversion. | 24th Jul 1928 | Box 50 \ 4 Scan210 | |
| Request to order the conversion of speedometer No. 706 for Mr. Royce's car. | 25th Jul 1928 | Box 50 \ 4 Scan211 | |
| Adjustment of speedometer gear ratios for two specific chassis. | 5th Aug 1928 | Box 50 \ 4 Scan212 | |
| Letter from A.T. Speedometer Co. Ltd. regarding the test results of an instrument. | 21th Aug 1928 | Box 50 \ 4 Scan213 | |
| Letter to The A.T. Speedometer Co. Ltd. regarding the performance and error of dial instruments. | 28th Aug 1928 | Box 50 \ 4 Scan214 | |
| The testing of A.T. Speedometers, assessing temperature effects and long-term reliability. | 29th Aug 1928 | Box 50 \ 4 Scan215 | |
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