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).
Note on the reduced purchase price of mica plates for armatures and historical insulation methods.
| Identifier | ExFiles\Box 50\1\ Scan017 | |
| Date | 23th March 1921 | |
| EFC from Wd.{Mr Wood/Mr Whitehead} X.4289 Wd{Mr Wood/Mr Whitehead}11/NJ23.3.21. X.4289 - Costs of Electrical Units. Referring to yours EFC1/T23.3.21, it may interest you to know that we are now purchasing mica plates for armatures at a lower price than formerly. In the old days at Cooke Street, it was the practice in some cases to employ mica insulators between all the soft iron armature plates and in other cases to employ mica insulators between a few of the soft iron armature plates at each end of the armature, the rest of the plates being insulated by varnish. Possibly R.{Sir Henry Royce} may refer to this when replying to your note. Hs{Lord Ernest Hives - Chair} MAR 28 1921 RECEIVED Wd.{Mr Wood/Mr Whitehead} Wd.{Mr Wood/Mr Whitehead} | ||