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).
Calculations comparing the hole area of various ebonite separator samples.
| Identifier | ExFiles\Box 54\5\ Scan038 | |
| Date | 16th October 1925 | |
| X4651 16.10.25. HOLE AREA OF EBONITE SEPARATORS. The original thinner sample, representing (.4 mm) standard, is 100 x π/4 x (.068)^2 = .363 . The thicker (1 mm) sample referred to on sheet dated 10.6.25 = = 137 x π/4 x (.055)^2 = .326 The new .6 mm. sample now proposed = 55.3 x π/4 x (3/32)^2 = .382 Thus the 1 mm. thick sample has 11% more hole area than the present standard, and the new proposed standard of .6 mm. will contain 17% more hole area than the present standard. ____ EFC. {E. Fowler Clarke - Electrical Engineer} | ||