Larry Bunce • Link
Organs for home use have always been for the well-off, but pipe organs come in sizes small enough to be carried around. I tried a search on 17th century English organs, and found this site for an organ building and restoration firm that has worked on organs of Pepys' era. One example given here looks like the entrance shown in a picture of the Bridewell Prison. The organ shown in the organ restorer's site is a bit awkwardly proportioned, with the facade pipes contained in a Palladian window sort of an opening. I was confused by Pepys' description at first, but now that I see this organ, I am amused by Pepys' apt and clever description of the organ's form.
On this page, there is a link to restoration projects. The 2nd organ on the top row of pictures was built a century after Pspys' time, but change was not quite so rapid in those days.
The organ itself dates to ancient times, where the well-furnished Roman villa included a hydraulis for entertainment. The Hydraulis, or "water organ," used air to sound the pipes, but steadied the wind from a pair of pumps shaped like large bicycle tire pumps, by means of an inverted funnel contained in a water tank. Air pressure in excess of that which sounded the pipes forced water out of the funnel, and then water pressure kept air flowing into the pipes when the pump was on its intake stroke.
This system actully provided a better wind supply than was possible until the 1820's when a system of feeder and reservoir bellows was invented.