I have put this into a separate category as these instruments contain no pipes so are not, in the historical sense, organs at all. Harmoniums (and American reed organs) produce their sound by passing air through brass reeds causing them to vibrate in sympathy with their length, exactly like accordions and harmonicas. These are "free" reeds, which vibrate freely in their housings, unlike the "beating" reed type normally found in pipe organs.
The mechanism behind the stop knobs may seem rather crude, but it needs to be carefully overhauled to carry out its task without undue effort on the part of the player. Beneath the keyboard is an intricate array of rods and wires, fitted with felt bushings. These all need to be meticulously cleaned, re-bushed and adjusted to provide the player with the required response to their touch. Octave couplers in particular warrant much attention to detail.
The instrument's innards can be easily removed for restoration. The case left in situ will prevent it becoming damaged in transit, and when closed will continue to serve its purpose as an elegant piece of furniture during the restoration period - unless, of course, the case itself needs attention.
I have included brief descriptions of two such restoration jobs:
61-note English harmonium
American reed organ
They were produced in vast quantities around the turn of the twentieth century. Those left in restorable condition are now becoming collectors items. However, examples in excellent working order are increasingly rare. Not only are they antique items of furniture, but are musical instruments with a real "live" sound.
The traditional English harmonium is pressure operated, with a horizontally mounted reservoir and feeders below. They are relatively rare, compared to American reed organs, which have a suction reservoir and feeders operated by canvas strapping over rollers from the pedals. The reservoirs and feeders are invariably covered with rubber-cloth.
The one pictured here is a harmonium of unknown make. The label says "S. Watson, Music Warehouse, Kidsgrove", the retailer. This instrument has the English bellows system, but instead of rubber-cloth, it uses leather. Re-covering is a highly skilled task, and should only be attempted by an experienced technician, using the correct materials.
I restored this harmonium in 2007, and as the case needed attention it was transported to my workshop in its complete state. The first task was to completely dismantle it, and note what needed to be done before it was rebuilt.
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Above left: The first item to work on was the case itself. It had split in several places, but as the panels were of odd shapes clamping them together was somewhat difficult. Once complete, the cabinet was treated with specialist scratch remover, and polished. Above right: The bellows system is clearly seen (before dismantling). The player pumps the foot pedals which are connected to the two feeder bellows. Air (wind) is pumped through the transfer trunks on either side to the main windchest above, (at the top of the picture). Between these trunks is suspended the main reservoir - held closed by the "bed" springs. Pumping pushes the reservoir bottom against the springs, producing compressed air for playing.
This picture shows just how many parts make up the bellows system. They don't include hinge cloth and bellows leather. The angular pieces are "ribbing", needed to prevent the air inside the inflated bellows from blowing them inside-out. They are not necessary with the American "suction" type of bellows.
The next few pictures show progress while re-assembling the bellows.
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Above left: One of the two feeders being assembled with leather hinges. Above right: One feeder now fully leathered. A small "bed" spring is installed inside to help open the bellows when the player's foot is lifted.
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Above left: The reservoir is held open while the ribbing hinges are glued into position. The outer hinge leather strips are applied , then the corner gussets. Above right: The completed installed assembly.
The note action involves the 61-key keyboard and its associated mechanism. This instrument is relatively simple, having only one set of reeds, and no stop knobs, usually a familiar sight. Each key of the 61 keys on the keyboard operates a lever with a pallet valve on the other end.
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Above left: One of the pallets just after removal - clearly in need of restoration. Above right: After stripping and cleaning, the pallets were glued to strips of leather, then cut apart with a scalpel. They were then glued to the arms via small leather pads to allow them to seat properly over the valve holes.
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Left: The reeds needed little attention at this stage; they were in very good condition. Any tweaking would be done at the setting-up stage after re-assembly. Above: The newly restored pallets were re-installed along with their cleaned springs. The red felt pads provide silent coupling with the push-rods under the keys.
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(Above left:) The guide holes under the front of the keys were badly worn, allowing them to move sideways and rubbing against each other. The cure was to carefully ease the timber around the holes inwards - with a suitable screwdriver (above right). This is a skilled job not to be attempted at home! Very badly worn holes would need inserts of clean timber, which is a more time-consuming task.
The only task left was to regulate the reeds where necessary, and to re-fit the action and keyboard back into the restored case, and fit the keyboard lid and music desk ready for a proud owner to display (and play) in the living room.
Unfortunately, not many pictures were taken of this job. However, this type of instrument is far more common than the English harmonium. Instead of the wind being forced up through the reeds from a set of pressure bellows, it gets sucked downwards through the reeds into a vacuum box by a pair of suction bellows mounted vertically at the back of the base section of the instrument. They are still operated by the player's feet, but the springs are mounted inside the bellows and reservoir, which is usually covered with "bellows cloth", a cotton cloth faced with a very thin layer of rubber. As the internal springs try to force the bellows apart, the job of assembling them needs careful use of special clamping brackets until the glue is thoroughly set.
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This instrument has the familiar stop knobs, and is fitted with two sets of reeds, one louder then the other (sometimes an octave apart). The knobs operate valves silencing the reeds when the knobs are pushed in. Knee-swells are often fitted, one operating shutters to allow more volume of sound, and another would allow a set of octave-coupling levers to bring into play the reeds an octave above the ones actually played (only on a limited number of keys). Another knob operates a "sub-octave" coupler to operate lower reeds. These levers can be seen in the picture (above right).
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(Above left:) One reed removed from its position in the row shown at the top of the picture. The reeds simply pull out of their slots. (Above right:) This shows a spacing post inserted to stop the key rail above from sagging downwards, affecting the player's key-touch.