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).
Drawing of a Morse 1/2' pitch, -1866N- type chain on a 19T sprocket, shown at 10 times size.
| Identifier | ExFiles\Box 128\3\ scan0198 | |
| Date | 20th May 1938 | |
| The Morse Chain Co LD. Letchworth, Herts. 10 TIMES SIZE MORSE 1/2" PITCH. -1866N- TYPE CHAIN. ON 19.T. SPROCKET. Pitch Curve J.C.P. C. 1558. | ||