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).
Detailed specification and pricing for the Ashdown Rotoscope and accessories.
| Identifier | ExFiles\Box 143\3\ scan0184 | |
| Date | 15th April 1940 guessed | |
| Page Six set at random and adjusted when viewing the object, for obtaining any unknown speed within the range. There are no charts, and the need for stop watches, attached speed counters, tachometers or guesswork is completely eliminated. "Displaced-type" Shutter for 320/12,000 for minute range. (Supplied as spare when specially ordered) Page Seven DETAILED SPECIFICATION OF THE ASHDOWN ROTOSCOPE SPEED RANGE, 160 to 6,000 per minute.* The instrument is self-contained and self-driving by means of a powerful mechanical movement, manufactured to high limits of accuracy, and equipped with an infinitely variable speed graduation within the full range obtainable in two steps through a change-speed gear knob. Speed setting is arranged on two scales; one, the rack scale reading clearly in “hundreds”; the other, the unit scale on the controller wheel dividing the rack scale. Patent “bladed” shutter (or sight gear) of special material and formation to ensure dynamical balance and smooth running at all speeds; fitted in hardened steel pintles borne in ring sapphires, and driven through a special form of “equaliser” to give cyclic constancy when viewing. Two-speed gear operated by simple knob at side to control the “high” and “low” settings. Aperture glasses, precision ground, and finished double plano to optical accuracy. The whole mechanism of highest-class instrument maker’s workmanship: London made. Heavy plated-brass framing; exterior in aluminium; black crystal-lacquer finish. The above instrument complete with winder, master key, and full directions: all contained in special baize-fitted cabinet with lock and key: PRICE ... £36 0s. 0d. net Carriage paid in Great Britain or f.o.b. English port: packing 7/6, returnable inland; overseas 15/-, non-returnable. Despatch ............ from receipt of order. Shipping: Weights, net 10lb., gross 17lb.; dimensions, 16in. x 16in. x 10in. (approx.) *An additional shutter can be furnished with this instrument to increase speed range to 160/12,000 per minute. PRICE (if desired) ... £3 3s. 0d. net | ||