From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Letter from The Capac Company Ltd. regarding Bin-Aural instruments (Tectoscopes) for noise detection.
| Identifier | ExFiles\Box 155\3\ scan0053 | |
| Date | 24th February 1936 | |
| X1325 The Capac COMPANY LTD MANAGING DIRECTOR C. E.{Mr Elliott - Chief Engineer} NOEL-STORR, F.R.S.A; M.I.A.E. TELEPHONE: PROSPECT 4217 Registered Office: 6, OLD JEWRY, LONDON, E.C.2. BIN-AURAL INSTRUMENTS FOR DETECTION, LOCATION AND COMPARISON OF NOISE and WEAR IN MECHANISM. Reply to: 26, Brookwood Avenue, Barnes, S.W. 13. Messrs Rolls-Royce Ltd. Nightingale Road Derby. 24-2-36 Your ref. Hs{Lord Ernest Hives - Chair}/Smth/5/EW. Dear Sirs, We thank you for letter to hand, and note that you did not find the instrument selective enough for your purpose. We take it that you were using a pair of Tectoscopes arranged for Comparison, as in Fig. 3 on instruction sheet, and we would mention that type A.{Mr Adams} Tectoscopes are supplied in the set as standard, and these will bring in a small watch tick. To obtain greater selectivity we suggest the use of type B. reproducers, which do not bring in the minute sounds which may be causing you some confusion and the less sensitive reproducers may serve your own purpose better than the sensitive type supplied. Perhaps you would do us the favour of making another test with type B. Tectoscopes, and if so we shall be pleased to forward you another set. at the same time it would assist us if you would state how the test is to be applied. We are, Faithfully yours. FOR & ON BEHALF OF THE CAPAC Co. LTD. C Noel Storr DIRECTOR | ||