Venetian and Ruckers 17th century Jacks

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The Venetian Jack


How oft when thou, my music, music play’st,
Upon that blessed wood whose motion sounds
With thy sweet fingers when thou gently sway’st
The wiry concord that mine ear confounds,
Do I envy those jacks that nimble leap,
To kiss the tender inward of thy hand,
Whilst my poor lips which should that harvest reap,
At the wood’s boldness by thee blushing stand!
To be so tickled, they would change their state 
And situation with those dancing chips,
O’er whom thy fingers walk with gentle gait,
Making dead wood more bless’d than living lips.
     Since saucy jacks so happy are in this,
     Give them thy fingers, me thy lips to kiss.

This jack is built upon the principles of the late 16th and early 17th  century Venetian harpsichord and virginal builders, in particular Benedetto Floriani and Giovanni Antonio Baffo. 

Using only measurements known to these two builders as the Venetian inch, or oncia, which has been shown to be the unit both of these two builders based their instruments around, and in conjunction with  my own measurements from the 1571 Floriani virginals, (Stattliche Institut für Musikforschung, Berlin), I have been able to reconstruct a superbly working jack which would have been very like those available to 16th and 17th century builders.

Various woods were available to Venetian builders and these woods can also be offered today. (Black walnut (introduced to Europe in 1629) and holly depicted.) In keeping with Italian tradition, the tongue is centred within the body to enable movement within box registers. 

The quill mortices dimensions on these jacks have been carefully designed and flare out very slightly to the rear to enable the secure fitting of either delrin or crow quill. The jack can be fitted with a leather or parchment detail to cushion the tongue’s return. 

My jacks are hand made to the finest standards and the lowest possible tolerances. I am able to offer custom jacks built to different modular measurement unit sizes on request.




Jack Body:
Length: 4 oncia (115 mm)
Width: 5 linee (12.1 mm)

Thickness: 2 linee (4.9 mm)

Damper slot: 5 linee (12.1 mm)

Pivot from top: 8 linee (19.32 mm)

Pivot thickness: 0.25 linee (0.6 mm)

Tongue mortice (back): 11 linee (26.5 mm)

Angle of mortice foot: 45°

Spring: hog bristle or brass sheet

Damper slot thickness: 2/5 linne (0.94 mm)


Length: 1 oncia (28.89 mm)

Thickness: 1.25 linee (3.0 mm)

Width: 1.75 linee (4.2 mm)

Quill from top: 4 linee (9.66 mm)

Angle of tongue point: 30°

Angle of plectrum mortice: 6°

Quill mortice width: 4/5 linee (1.94 mm)

Quill mortice height: 2/5 linee (0.97 mm)

Possible plectra: crow quill, plastic




ruckers jacks

I offer Ruckers jacks which adhere faithfully to measurements generated from the workinch, or weckzoll, used by the Ruckers dynasty as their measurement unit. These jacks are of the very highest quality and individually made by hand with every detail attended to with precision and historical accuracy. These are a must have for anyone building or owning an original harpsichord or copy of any Ruckers, Couchet or van Everbroek instrument.


Jack Body:

Length: (upper manual): 4 modular inches (110.84mm)

Lenth: (lower manual/single): 7 modular inches (193.97mm)

Width at top: 1/2 modular inch (13.85mm)

Width at bottome: 15/32 modular inch (12.99mm)

Thickness at top: 9/64 modular inch (3.9mm)

Thickness at bottom: 7/64 modular inch (3.03mm)

Pivot from top: 51/64 modular inch (22.08mm)

Quill morise from top: 23/64 modular inch (9.96mm)

Quill mortise angle: 10°

Damper mortise lower edge from top: 19/64 modular inch (8.22mm)


Width: 5/32 modular inch (4.3mm)

Thickness at top: 1/32 modular inch (2.16mm)

Thickness at pivot: 7/64 modular inch (3.03mm)

Tongue length: 1 1/32 modular inch (28.57mm)

Available Timbers: