| Title: | Backfalls of the Positive or Small organ |
| Original Title: | Bascules du positif, ou Petit orgue |
| Volume and Page: | Vol. 2 (1752), pp. 114–115 |
| Author: | Unknown |
| Translator: | Charles Ferguson [Colby College, Emeritus] |
| Original Version (ARTFL): | Link |
| Rights/Permissions: |
This text is protected by copyright and may be linked to without seeking permission. Please see http://quod.lib.umich.edu/d/did/terms.html for information on reproduction. |
| URL: | http://hdl.handle.net/2027/spo.did2222.0003.955 |
| Citation (MLA): | "Backfalls of the Positive or Small organ." The Encyclopedia of Diderot & d'Alembert Collaborative Translation Project. Translated by Charles Ferguson. Ann Arbor: Michigan Publishing, University of Michigan Library, 2020. Web. [fill in today's date in the form 18 Apr. 2009 and remove square brackets]. <http://hdl.handle.net/2027/spo.did2222.0003.955>. Trans. of "Bascules du positif, ou Petit orgue," Encyclopédie ou Dictionnaire raisonné des sciences, des arts et des métiers, vol. 2. Paris, 1752. |
| Citation (Chicago): | "Backfalls of the Positive or Small organ." The Encyclopedia of Diderot & d'Alembert Collaborative Translation Project. Translated by Charles Ferguson. Ann Arbor: Michigan Publishing, University of Michigan Library, 2020. http://hdl.handle.net/2027/spo.did2222.0003.955 (accessed [fill in today's date in the form April 18, 2009 and remove square brackets]). Originally published as "Bascules du positif, ou Petit orgue," Encyclopédie ou Dictionnaire raisonné des sciences, des arts et des métiers, 2:114–115 (Paris, 1752). |
Backfalls of the Positive or Small organ. Illustrated in [Plate V] figure 22, they are strips, A B , of oak, five or six feet long, and wider at the center than at the tips; these strips are placed on edge at their centers on a balance rail, F, set with pins, G . The pins fit into holes drilled at the centers of the backfalls . The holes must be made slightly wider at the top than at the bottom, where they rest on the balance rail, but only lengthwise of the backfall . At one end of the backfall , B , a small hole is drilled vertically, to receive a pin inserted in the lower end of sticker EC . Stickers are rods of oak, four or five lignes [1] in diameter; their upper ends run through board D (and fig. 2, D D ), drilled with as many holes as there are stickers; there are as many stickers as there are keys in the keyboard, beneath which they are to be located. When the stickers are in the guide holes, their upper ends bear against the undersides of the keys, about one-half foot from the front of the keyboard. Ends A of the backfalls lie beneath the windchest, which is provided with iron pins, between which the backfalls move. These are called the backfall guide pins ; indeed, they guide the movement of the backfalls .
When the organist depresses a manual key, it pushes sticker EC , lowering end B of the backfall and consequently raising end A , which pushes up the little rod that extends through the purse; this opens the pallet, and when opened, the pallet admits wind to the channel in the chest. See Windchest, Positive, Purse, etc.
At their sticker ends, the backfalls have the same span as the keyboard, and they diverge towards their windchest end, where they have the same span as the pallets in the chest. The backfalls are located under the platform between the great organ and the positive, on which the organist’s bench is placed. The sticker ends are inside the foot of the main organ case, and the other ends are beneath the windchest in the positive.
1. A ligne is one-twelfth of a pouce or inch (Translator’s note).