Glossary of Abbreviations & Terminologies

by John Stiller, Research Officer
Organ Historical Trust of Australia
Ø ext. External diameter
Ø int. Internal diameter
SM Spotted metal
PM Plain metal
Zn Zinc
NS Normal Scale (according to Töpfer Index).

All measurements are in millimetres unless otherwise stated. Stop names are designated as they appear on the stop labels.
Nicking on the languid is shown as:
Nicking on the lower lip is shown as:
Note designations are as follows:

For wooden pipes

Where two dimensions are given, the first figures refers to the mouth-side, the second figures refers to the adjacent side, e.g. external dimesions of 24 x 36 would mean that the side containing the mouth has an external measurement of 24mm; the adjacent side being 36mm.

Similarly, where a difference in the thickness of wood occurs, the thickness of the side into which the mouth is cut is shown first. e.g. 6 x 7 would mean that the side into which the mouth is cut has thickness of 6mm.

Workmanship of mouth for wooden pipes

5 different terminologies are used:
  1. "no ears"
  2. "half ears"
  3. "level ears"
  4. "protruding ears"
  5. "inverted mouth".
Their differences may be described as follows:

1. "no ears". The sides of the mouth have been completely cut away so that no "ears"are present.
2. "half ears". The sides of the mouth have been bevelled, so that only half "ears" remain.
3. "level ears". The sides of the mouth are left untouched, leaving "ears" level with the pipe body.
4. "protruding ears". Ears have been added to the sides of the mouth.
5. "inverted mouth". The pipe is of such a construction that there is no bevel present on the external surface of the upper lip.

Relationship to Töpfer Index*

In this documentation, scales for metal pipes are related to the Töpfer Index. This standard for pipe scaling was laid down by the German organ theoretician, J.G. Töpfer, in the mid-19th century. Originally this standard attempted to define pipe measurements which would ensure a perfectly regular and even tone colour throughout the entire range of a particular rank of pipes. This was to be achieved purely by scientific and mathematical principles.

It was found that this aim was best fulfilled when the internal diameters of the pipes constituting such a rank were halved at every 17th note. Thus, a standard measurement was adopted for any pipe of any length. This measurement defined the internal diameter that pipe should have in order for the mathematical and scientific principles of pipe construction to be followed. This standard was called Normal Scale, and any pipe of a particular length having the internal diameter suggested by the Töpfer Index is said to have Normal Scale (NS). However, if a pipe of a particular length has the internal diameter of the next smallest pipe on the Töpfer Index, it is defined as having a scale of -1.

* P.G. Andersen: Organ Building and Design, Allen & Unwin, 1969, p58.

© Organ Historical Trust of Australia 1980
P.O. Box 200, Camberwell, Victoria 3124, Australia
This document is copyright. Apart from fair dealing for the purposes of private study, research, criticism or review, as permitted under the Copyright Act, no part may be reproduced by any process without written permission. Enquiries should be made to the publisher.