| Description | Date | Identifier | |
| Letter from The British Thermostat Co., Ltd. confirming a sample thermostat is being made to drawing BGA. 3754. | 20th Dec 1937 | Box 156 \ 1 scan0356 | |
| Despatch of a master thermostat casing for setting thermostats on 'M' series Bentley cars. | 23th Dec 1937 | Box 156 \ 1 scan0357 | |
| Forwarding a master casing for thermostats to the British Thermostat Co. Ltd. and increasing an order. | 23th Dec 1937 | Box 156 \ 1 scan0358 | |
| Letter to British Thermostat Co. Ltd. regarding a master thermostat casing and an increased order. | 23th Dec 1937 | Box 156 \ 1 scan0359 | |
| Letter from The British Thermostat Co., Ltd. regarding an order for thermostats, referencing drawings and parts. | 28th Dec 1937 | Box 156 \ 1 scan0360 | |
| Forwarding a copy of a letter sent to Messrs. S. Smith & Sons Ltd. | 30th Dec 1937 | Box 156 \ 1 scan0361 | |
| Letter to S.Smith & Sons Ltd. regarding an invoice for a thermostat and a request for a second one for testing. | 30th Dec 1937 | Box 156 \ 1 scan0362 | |
| Letter from S. Smith & Sons regarding a misunderstanding over a charge for a B.V. Thermostat, code X.30065. | 31th Dec 1937 | Box 156 \ 1 scan0363 | |
| Letter to S. Smith & Sons Ltd. regarding test results and requested alterations for a thermostat unit. | 3rd Jan 1938 | Box 156 \ 2 scan0001 | |
| Request for a drawing and quotation for 1,000 thermostat units for a 25 HP Vauxhall with a modified temperature setting. | 3rd Jan 1938 | Box 156 \ 2 scan0002 | |
| Quotation letter from The British Thermostat Co., Ltd. for 1,000 thermostats. | 4th Jan 1938 | Box 156 \ 2 scan0003 | |
| Blueprints for a Bentley 11 Thermostat System and Thermometer Bottle. | 4th Jan 1938 | Box 156 \ 2 scan0004 | |
| Letter from S. Smith & Sons regarding the performance and supply of thermostat units. | 6th Jan 1938 | Box 156 \ 2 scan0005 | |
| Official order for one thermostat from S. Smith & Sons Ltd. | 10th Jan 1938 | Box 156 \ 2 scan0006 | |
| Letter from S. Smith & Sons confirming an order for a thermostat set to start opening at 78/80° C. | 10th Jan 1938 | Box 156 \ 2 scan0007 | |
| Official order be placed for a modified thermostat from S. Smith & Sons Ltd. | 10th Jan 1938 | Box 156 \ 2 scan0008 | |
| Letter to S. Smith & Sons Ltd. requesting a new thermostat and discussing dissatisfaction with the temperature range of another. | 8th Jan 1937 | Box 156 \ 2 scan0009 | |
| Letter from S. Smith & Sons concerning the specifications and testing of a thermostat. | 14th Jan 1938 | Box 156 \ 2 scan0010 | |
| Thermostat bypass scheme to reduce cost and a change in the thermostat unit to reduce weight. | 21th Jan 1938 | Box 156 \ 2 scan0011 | |
| Requesting the production of a second set of parts for a Bentley II thermostat scheme experiment. | 21th Jan 1938 | Box 156 \ 2 scan0012 | |
| Official order be sent to Messrs. S.Smith & Sons for a thermostat unit and conversion work. | 25th Jan 1938 | Box 156 \ 2 scan0013 | |
| The return of a thermostat unit to S. Smith & Sons Ltd. for modification. | 25th Jan 1938 | Box 156 \ 2 scan0014 | |
| Letter to The British Thermostat Co. Ltd. regarding the specifications for a thermostat sample. | 25th Jan 1938 | Box 156 \ 2 scan0015 | |
| Letter to S. Smith & Sons Ltd. discussing modifications and quotes for a special thermostat unit. | 25th Jan 1938 | Box 156 \ 2 scan0016 | |
| Letter to S. Smith & Sons Ltd. requesting a second unit of a specified valve type. | 25th Jan 1938 | Box 156 \ 2 scan0017 | |
| Letter from The British Thermostat Co., Ltd. regarding a sample thermostat and drawing BGA. 3754. | 26th Jan 1938 | Box 156 \ 2 scan0018 | |
| Letter from S. Smith & Sons acknowledging an order for a thermostat, code X.30065, and advising of a delay in providing a quotation. | 26th Jan 1938 | Box 156 \ 2 scan0019 | |
| Quotation letter from S. Smith & Sons for Thermostat units. | 28th Jan 1938 | Box 156 \ 2 scan0020 | |
| Request to supply a thermostat assembly, pump cover, and bypass pipe for a streamlined M-series Bentley II chassis. | 4th Feb 1938 | Box 156 \ 2 scan0021 | |
| Return of a failed Bentley thermostat unit for examination and replacement. | 11th Feb 1938 | Box 156 \ 2 scan0022 | |
| Letter from The British Thermostat Co. acknowledging the failure of a thermostat referenced by drawing number EB. 3509. | 14th Feb 1938 | Box 156 \ 2 scan0023 | |
| Letter from a supplier discussing the failure of a thermostatic unit and proposing a solution. | 15th Feb 1938 | Box 156 \ 2 scan0024 | |
| Letter concerning thermostat bellows failure and proposed testing of experimental units. | 16th Feb 1938 | Box 156 \ 2 scan0025 | |
| Letter from The British Thermostat Co. regarding a suggestion for a baffle plate for a thermostat. | 16th Feb 1938 | Box 156 \ 2 scan0026 | |
| Failure of a bellows unit in an M.Series thermostat system. | 17th Feb 1938 | Box 156 \ 2 scan0027 | |
| Analysis of a bellows unit failure, discussing valve opening dimensions and awaiting manufacturer information. | 17th Feb 1938 | Box 156 \ 2 scan0028 | |
| Letter from The British Thermostat Co. Ltd. discussing a failed thermostatic unit and proposed solutions. | 15th Feb 1938 | Box 156 \ 2 scan0029 | |
| Return and repair of two thermostat units, one to be repaired free of charge. | 17th Feb 1938 | Box 156 \ 2 scan0030 | |
| Letter to The British Thermostat Co. Ltd. regarding a potential bellows failure in a unit. | 18th Feb 1938 | Box 156 \ 2 scan0031 | |
| Instruction to despatch a Thermostat Unit for repair to British Thermostat Co. Ltd. | 18th Feb 1938 | Box 156 \ 2 scan0032 | |
| Letter concerning a potential bellows fault on a new unit due to water pressure and assuring future deliveries will be correct. | 19th Feb 1938 | Box 156 \ 2 scan0033 | |
| Letter from The British Thermostat Co. Ltd. concerning the testing and return of bellows assemblies. | 21th Feb 1938 | Box 156 \ 2 scan0034 | |
| Instruction to fit a thermostat and a stainless steel thrust plug to the B.III No.1 engine unit while on the test bed. | 10th Mar 1938 | Box 156 \ 2 scan0035 | |
| Letter detailing the results of testing new thermostat units and their bellows measurements after 450 miles of running. | 11th Mar 1938 | Box 156 \ 2 scan0036 | |
| The unsatisfactory performance of bellows units, detailing measurements and operational concerns. | 11th Mar 1938 | Box 156 \ 2 scan0037 | |
| List of measurements for bellows length and valve lift under various conditions. | 12th Mar 1938 | Box 156 \ 2 scan0038 | |
| Letter from The British Thermostat Co. Ltd. requesting the return of a discharged thermostat for measurement clarification. | 12th Mar 1938 | Box 156 \ 2 scan0039 | |
| Thermostat unit being sent for repair to The British Thermostat Co. Ltd. | 15th Mar 1938 | Box 156 \ 2 scan0040 | |
| Sending a thermostat unit for repair to The British Thermostat Co. Ltd. | 15th Mar 1938 | Box 156 \ 2 scan0041 | |
| Letter to The British Thermostat Co. Ltd. regarding revised measurements for a thermostat bellows unit. | 15th Mar 1938 | Box 156 \ 2 scan0042 | |
| The second page of a letter from the Experimental Department concerning alterations to figures. | 15th Mar 1938 | Box 156 \ 2 scan0043 | |
| Table of measurements detailing the movement of a bellows unit under various conditions. | 18th Mar 1938 | Box 156 \ 2 scan0044 | |
| Letter to The Drayton Regulator Co. requesting lists and particulars of automobile thermostats and bellows. | 18th Mar 1938 | Box 156 \ 2 scan0045 | |
| Letter from The British Thermostat Co., Ltd. regarding a disagreement over bellows measurements. | 28th Mar 1938 | Box 156 \ 2 scan0046 | |
| Letter from a supplier discussing dimensional discrepancies of a returned bellows unit and suggesting a material change for rebuilding. | 28th Mar 1938 | Box 156 \ 2 scan0047 | |
| Request to send an official order to S. Smith & Sons Ltd. for a thermostat with a special opening temperature. | 28th Mar 1938 | Box 156 \ 2 scan0048 | |
| Letter of complaint regarding a supplied American car heater, comparing it unfavorably to a lighter unit and requesting a specific thermostat. | 28th Mar 1938 | Box 156 \ 2 scan0049 | |
| Letter from The British Thermostat Co. regarding the forwarding of a thermostat and proceeding with the manufacture of 50 units. | 30th Mar 1938 | Box 156 \ 2 scan0050 | |
| Letter to The British Thermostat Co. Ltd. regarding the use of 'Alumbro' for thermostat bellows and measurement discrepancies. | 30th Mar 1938 | Box 156 \ 2 scan0051 | |
| Letter discussing car heater component failures and requesting quotations for new parts. | 31th Mar 1938 | Box 156 \ 2 scan0052 | |
| The M. series Bentley thermostat unit, discussing material changes and testing. | 31th Mar 1938 | Box 156 \ 2 scan0053 | |
| Letter from a supplier regarding thermostat characteristics, the composition of 'Alumbro', and a quotation for car heater motors. | 1st Apr 1938 | Box 156 \ 2 scan0054 | |
| Letter from The British Thermostat Co. Ltd. concerning prices, a car heater switch and acknowledging receipt of drawings. | 2nd Mar 1938 | Box 156 \ 2 scan0055 | |
| Requesting an official order for a thermostat fitted with 'Alum-bro' material bellows. | 2nd Mar 1938 | Box 156 \ 2 scan0056 | |
| Letter concerning overheated motor rheostats and a request for further specifications before providing a quotation. | 4th Apr 1938 | Box 156 \ 2 scan0057 | |
| Letter from S. Smith & Sons clarifying a confusion over a special thermostat order and associated part codes. | 5th Apr 1938 | Box 156 \ 2 scan0058 | |
| Letter to S. Smith & Sons Ltd. clarifying thermostat specifications, size, and opening temperature. | 5th Apr 1938 | Box 156 \ 2 scan0059 | |
| Requesting an official order for one thermostat from The British Thermostat Co. Ltd. | 1st Apr 1938 | Box 156 \ 2 scan0060 | |
| Letter to S. Smith & Sons Ltd regarding the testing of a thermostat and its bellows unit. | 6th Apr 1938 | Box 156 \ 2 scan0061 | |
| Letter to The British Thermostat Co. Ltd. regarding thermostats and their replacements. | 8th Apr 1938 | Box 156 \ 2 scan0062 | |
| Short telegram message confirming a convenient time for a meeting or call. | 9th Apr 1938 | Box 156 \ 2 scan0063 | |
| Letter from S. Smith & Sons regarding thermostat performance and bellows specifications after a 10,000-mile test. | 9th Apr 1938 | Box 156 \ 2 scan0064 | |
| Letter from S. Smith & Sons regarding the examination of Bellows for thermostats. | 9th Apr 1938 | Box 156 \ 2 scan0065 | |
| Request for an official order to The British Thermostat Co. Ltd. for one thermostat. | 11th Apr 1938 | Box 156 \ 2 scan0066 | |
| Letter to The British Thermostat Co. Ltd. regarding the testing and comparison of thermostats and heater motors. | 12th Apr 1938 | Box 156 \ 2 scan0067 | |
| Letter discussing the two fans used on a motor and their power consumption. | 13th Apr 1938 | Box 156 \ 2 scan0068 | |
| Letter from The British Thermostat Co., Ltd. regarding sample thermostats, bellows, and heater switch wattage. | 13th Apr 1938 | Box 156 \ 2 scan0069 | |
| Letter from The British Thermostat Co. Ltd. regarding modifications to rheostats and a mislaid sample motor. | 22th Apr 1938 | Box 156 \ 2 scan0070 | |
| Letter from The British Thermostat Co. Ltd. regarding a carburetter and thermostat units. | 22th Apr 1938 | Box 156 \ 2 scan0071 | |
| Sending a thermostat to central stores for return to The British Thermostat Co. Ltd. | 22th Apr 1938 | Box 156 \ 2 scan0072 | |
| Letter to The British Thermostat Co. Ltd. regarding the return and investigation of a sample thermostat with 'Alumbro' bellows. | 22th Apr 1938 | Box 156 \ 2 scan0073 | |
| Letter from The British Thermostat Co. regarding a water hammer issue caused by a bellows and valve area mismatch. | 23th Apr 1938 | Box 156 \ 2 scan0074 | |
| Sending a thermostat to the Repair Stores for modification by the British Thermostat Co. Ltd. | 25th Apr 1938 | Box 156 \ 2 scan0075 | |
| Request to detail a modified thermostat valve and thermostat casing with increased dimensions. | 26th Apr 1938 | Box 156 \ 2 scan0076 | |
| Request to modify a casing and create two valves to test a thermostat modification for M series Bentley thermostats. | 20th Apr 1938 | Box 156 \ 2 scan0077 | |
| Letter from S. Smith & Sons regarding an investigation into a thermostat bellows that failed to fully open. | 27th Apr 1938 | Box 156 \ 2 scan0078 | |
| Letter from S. Smith & Sons regarding an investigation into a thermostat bellows issue and the supply of new samples. | 3rd May 1938 | Box 156 \ 2 scan0079 | |
| Letter to S. Smith & Sons Ltd. regarding the testing and supply of thermostats and heaters. | 5th May 1938 | Box 156 \ 2 scan0080 | |
| Letter from S. Smith & Sons regarding the production of a smaller heater model and checking the length of bellows. | 6th May 1938 | Box 156 \ 2 scan0081 | |
| Letter from S. Smith & Sons to Mr. C.S. Steadman regarding the despatch and specifications of two thermostats. | 9th May 1938 | Box 156 \ 2 scan0082 | |
| Thermostats and an order for two special units from the British Thermostat Co. Ltd. | 10th May 1938 | Box 156 \ 2 scan0083 | |
| Letter to the British Thermostat Co. Ltd. regarding the testing of bellows to eliminate water hammer and an adjustment to an order. | 10th May 1938 | Box 156 \ 2 scan0084 | |
| Investigation into intermittent noise on 'M' series Bentley cars, traced to the thermostat valve operation and a proposed solution. | 10th May 1938 | Box 156 \ 2 scan0085 | |
| Instruction to hold production and fit a modified thermostat to M series Bentley car heaters to prevent noise complaints. | 10th May 1938 | Box 156 \ 2 scan0086 | |
| Internal request to send an official order for two thermostats already received from S. Smith & Sons Ltd. | 11th May 1938 | Box 156 \ 2 scan0087 | |
| Letter from The Drayton Regulator and Instrument Company Ltd regarding past correspondence and a proposal to supply Hydroflex bellows. | 13th May 1938 | Box 156 \ 2 scan0088 | |
| Further tests on thermostats for 'M' Series Bentley cars, focusing on valve and bellows combinations to resolve oscillation issues. | 16th May 1938 | Box 156 \ 2 scan0089 | |
| Letter concerning a rescheduled meeting to discuss Bellow requirements and to correct a typographical error from a previous letter. | 16th May 1938 | Box 156 \ 2 scan0090 | |
| Letter to The Drayton Regulator & Instrument Co. Ltd. regarding a thermostat unit quote and bellows. | 10th May 1938 | Box 156 \ 2 scan0091 | |
| Letter of complaint to S. Smith & Sons Ltd. regarding the exorbitant pricing of supplied experimental thermostats. | 16th May 1938 | Box 156 \ 2 scan0092 | |
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