Restoration of a Very Early French Harmonium: The Wind System Part 2

The wind system of a harmonium does not use bellows cloth, the rubberized canvas used in suction instruments. The purpose of a wind system in a suction instrument is to keep air out. In a pressure instrument the purpose is to keep air in. The wind system of a harmonium is somewhat like that of a pipe organ on a much smaller scale.

A leather gusset on the reservoir.

The wind system employs leather gussets that allow the reservoir and feeders to compress as air is pumped into the reservoir.  The leather used is very thin lamb or goat skin, no more than 1 mm in thickness.

The feeders showing the wooden ribs 

 

 

 

 

 

 

 

 

 

 

 

 

The traditional covering in harmoniums, especially French instruments, is a blue kraft paper.  Before the convenience of synthetic dyes which can reproduce any color found in nature (and many that are not) indigo was used to dye the paper. Originally this was simply to dress up the work and cover the wide glued edges of the leather, but builders soon found that the indigo acted as a natural insect repellent.

 

The reservoir leather done.

Gusset on the reservoir

 The first thing I did was to restore the reservoir with all new materials, leather hinges and gussets, and blue kraft paper. Thin lamb or goat skin works well for this. It compresses well and is flexible when glued. Pictured here is one of the gussets on the reservoir. When gluing it on I periodically wipe the leather with hot water which helps it stretch.

First, the reservoir releathered.

With the reservoir completed I turned to the feeder boards.  I put canvas hinges on the feeder boards and put leather hinges on the wide ends of the feeders.

The wooden ribs can be reused unless there is significant damage.

 

 

 

 

The feeder pumps are done except for the paper.

 

 

 

The wind system done!

 

....and installed back in the case!