Skytaly – Zbraslav

Restoration begun 1994 - completed 1997

In the Roman Catholic Church of St Marketa (1782-1784) there stood a positive organ to which had later been added pedals (the pedals were added in 1848 by the Cheb organ builders, Müller and Family), in a Late Renaissance style. It was a one manual instrument of slider chest construction, with the keyboard built on the base, and with a range of C - a'', with a short bottom octave and without g#''.

The specification at the time of dismantling according to the order of winding:

 1. Principal 2

2. Octave 4

3. Quint 2 2/3

4. Quint 1 1/3

5. Octav 1

6. Bourdon 8

7. Octave bass 8

The instrument was moved and re-sited several times and the specification changed. The actual original specification was discovered, however, after the dismantling of the slider chests, when, after steaming off damaged leather on the upper board the names of the stops were found. I also chose this initial specification for the restoration of the instrument

1. Principal 2

2. Octave 4

3. Quint

4. Sedecima

5. Cymbal II

6. Bourdon 8

This specification was confirmed also by comparing it to the pipes and the remains of the original pedal boards, as well as the notes on parts of the stop action.

The state of the instrument immediately after its dismantling was desolate. The case had loose joins, without any central carvings on the pipework, and without the wings of the front part. The mechanical action was damaged, with completely corroded metal, the  rollerboards were rotten in several places, with various parts of it badly infested with woodworm.

The pipes were broken and in pieces, the slider chests with horizontally glue-coated lime-tree boards in the upper part was cracked, especially the spruce plugs of the bars. The pallet valves were distorted, with corroded iron mountings, the sliders, some of which were broken, were damaged, with deep scratches.

The pipework was completed from lime wood with cracked and missing stops, attacked by woodworm and re-configured for another specification.

The pitch of the organ, however, had not been changed and retained Chorton (465 at 14⁰ C), for which the original pipes were preserved and extended with Cornetton.

Of the original pipework the following was conserved:

Principal 2

The pipes were situated in the case front, decorated with gold and silver leaf. 16 pipes were conserved, although damaged by acts of vandalism.

Octave 4

The wooden pipes for the bottom octave C - B^b , B - a'' with a high lead content, 28 pipes preserved.

Quint 1 1/2

12 original pipes preserved.

Sedecima

Breaking back at  c', 6 original pipes preserved.

Cymbal

Breaking back at c' and c'' 1/3 and ½, no original pipes preserved.

Bourdon 8

C – B^b  original (wood), B - a''  high quality pipes from the 18^th century without  g#', c'', c#'',d''.

The material for the pipework was, at the time of dismantling, composed of four types of pipework. From the oldest, 67 were preserved, which were used after the repair. The others are substitute replicas, with the exception of the Bourdon where the high quality pipework of later provenance was retained.

The Course of the Work

Casework

The instrument was dismantled, cleaned and the wooden part treated with cobalt. The case was completely taken apart, and a carpenter repaired all joints and destroyed parts, and completed replicas of missing parts and parts of the ornamentation according to remaining fragments. Parts of the renaissance colouring were uncovered. Like the prospect pipes they are gold and silver, and the whole organ case is richly decorated with gold and silver, dark red marble, with coloured flowers and ornamentations of grapes. A further stage of the restoration would see the renewal of the original colours.

Slider chests

After cleaning and polishing, the slider chests had their woodwork repaired. The cracked joints of the soundboard were first cleared by steaming of several layers of glued-on paper, afterwards partly replaced or repaired with filler (the holes left by the woodworm) or made airtight. To close the holes left by the woodworm in all cases a filler was used made of a mixture of beeswax, dammar and pigments.

The upperboard of the  slider chests formed lengthways by glued lime boards had become unstuck in several places and thus gaps up to 4mm wide had formed. After steaming off  the old torn leather these cracks were first, after planing, fixed with wooden nails, and then the gaps were filed to the edge of the channel and fixed with limewood. The  slider chests were repeatedly worked over with goat glue and the surface treated with a varnish made of a mixture of beeswax and dammar.

The air holes were, following the removal of the old leather, aligned and given a double covering of leather. Needless to say, the way in which they were fixed was preserved. The  key levers had been repaired relatively recently, or replaced with new ones and with the cover of the reservoir, and were therefore left alone except for a covering of glycerine.

The whole upperboard was coated with white sheep leather (the bars between the channels are only mounted on pegs and the holes for the air supply to the bar channel were burnt by iron. The sliders were repaired and equalised to the same size, namely 12 mm.

The rackboard made from hard limewood has divides chiselled out and covered with oak plugs. After removing the old vellum, they were all removed and reattached, in some cases replaced with new ones of the same material. All later repairs were removed and the holes for the pipes, where necessary, were bushed with limewood in such a way that it would be possible to place in them pipes of the original specification. The pipes are placed in the blocks without any so-called drop-ends, in holes burnt by iron according to the shape of the foot of the pipe, which is completely open at the bottom end.

Most work was required on the board holding the Quinta Minor, because prior to the restoration it had contained Quintbass, and all the holes had been enlarged. Along the whole length of the board, therefore, a piece of wood 10 mm high and 40 mm wide was planed away, and new lime was stuck on in which were drilled and burnt new holes for the pipes.

A similar intervention was also undertaken in the case of the boards for the Sedecima and Cymbal. The latter was covered with a non-original spruce board, which reduced the number of the Cymbal series. After its removal, the original holes for the Sedecima pipes were found as were also the chiselled holes of the orginal spaces for the two-rank Cymbal. Given that the board no longer had its original height, because it had been planed before the glueing on of the spruce board referred to above, I decided to produce from lime the upper screen for the whole board, to which were attached the Sedecima and Cymbal pipes. Both registers break back in parallel on c', and the Cymbal also on c'', as is evident from the original holes which have been partially preserved.

The upperboard for the Bourdon 8 was repaired in the past (the pipes of the lower octave were moved further from the Cymbal). After the renewal of the original specification, the original hidden holes were opened up, which made it possible to close the case with a rear panel, a fragment of which had been found. Owing to general decrepitude and the attacks of woodworm, and in some cases owing to resizing of pipes, it was necessary to replace all  rackboards with copies, made according to the original examples.

Pipes

The original tin pipes were repaired, when necessary completely taken apart, and resoldered. Loose inner fittings were fixed and the pipe mouths were aligned, and copies made in conformity with the orginal sizes and shapes. Where necessary, the upper lips of the original pipes were appropriately extended. All the tin pipes, except those which are visible, are cone-tuned.

The wooden pipes were polished with cobalt, impregnated against wood-eating insects with OPXL and repaired. The holes left by woodworm were filled with wax.  Copies of g#', c'', c#'' and d'' were made.

The voicing of the tin pipes was carried out only via the flue; the feet of the pipes are fully open. The tuning is mean tone according to Praetorius, 465 Chorton at 14 C⁰. Pressure is 65 mm WS.

Action

Seeing as the keyboard of the instrument was not original, I made a copy according to a contemporary model (ebony, mahogany, and bone) with engraving of all keys. The  rollerboards placed above the keys was repaired, the embedded parts, straps and trackers damaged by woodworm were replaced. The mounting is new brass, 1.6mm average size, the springs for the pallet valves are by Laukhuff. In the stop action some wooden links were repaired, the width was restricted and the damaged manubria cut.

Bellows and air supply

Seeing that the original bellows were not preserved and the financial possibilities of the owner and lessee are limited, I decided for the time being to use refurbished bellows from another more recent instrument with a Laukhuff blower. Its size allows it to be placed in the bottom of the instrument together with the reservoir. Future plans would see the completion of dual wedge-shaped bellows which will be placed outside the instrument in an independent construction.