Jonathan Holmes wrote in 010824 MMDigest, "Humidity Control for the
Piano & Dampp-Chaser":

> I have a great worry about some of these historic instruments, such
> as large fairground organs (band organs) being played on the rally
> field.  They are generally in a lorry or van, the sun is heating them
> up and the air being pushed through the blower is being warmed.

The main difference between pianos and fairground organs is that the
organs were originally built to travel out of doors, and have always
been subjected to extremes of temperature and humidity in the normal
course of their working life.

We usually see them at rallies, sitting in insulated trailers, some
fitted with humidifiers, when in their early days they were travelled
on open trucks with often only a sheet and a canvas tarpaulin to
protect them from the elements.  Moreover, these trucks originally had
wooden wheels, not the pneumatic tyres of today.  Even in winter, these
organs were usually kept on their trucks, parked in the showman's yard.
I have worked on one myself under the tied-back tarpaulin during a
snowstorm.

John Page