🚀 go-pugleaf

>>Q: what's the difference between a
>>   TESTATIKA machine and a Wimshurst machine?
>>A: Nothing!

>Well, it is similar to a Wimhurst machine.
>In the Testatika design there is a small electromotor which is fed from the
> output of the machine, so it is self running and needs no input power !
>It is started by hand and then runs on its own energy.

At the library I've found a ancient book published in 1908 titled:
"The Wimshurst Machine: How to make and use it" by Alfred Marshall.

Here is the introductory chapter: 

  The Wimshurst Influence Machine is a particular pattern for generating
static electricity by inductive action between charged metal plates
instead of a rubbing action, as in a frictional machine.  It is called
after the name of the inventor, James Wimshurst.
  In its simple form the machine consists of a pair of glass discs mounted
upon a spindle, so that they can be rotated in opposite directions at
a comparatively high rate of speed.  These discs are placed so that their
inner surfaces are as close together as practicable to allow of rotation.
Upon the outer surfaces are cemented a number of sector-shaped strips of
thin brass or tinfoil, spaced at equal distances.  Each disc has the same
number of these sectors, so that at a given instant the sectors on one
disc will be exactly opposite to those on the other.
  Facing the outside surface of each plate is a metal rod, to the ends of
which are fixed some light tinsel brushes, so adjusted that they touch
the metal sectors as the latter pass the brushes during the rotation
of the plates.  These neutralizing rods, as they are called, make metallic
connection between diametrically opposite sectors upon respective plates,
and are set at a right angle to each other, or less, to 60 degrees.

  Inductive Action.  When the plates are rotated an inductive action
takes place between the sectors of one plate and the sectors of the other.
The charge of static electricity existing upon any sector of one plate
exerts an influence upon the adjoining sector of the other plate,
according to the rules of static electricity.
  If a pair of diametrically opposite sectors of one plate are
respectively positively and negatively charged, they will act inductively
upon the adjoining similar pair of sectors of the other plate.  The
neutralizing rod, whose brushes press upon this second plate, makes
metallic connection between the sectors which are being acted upon, and
allows the induced electric charges to distribute themselves.  As the
plates continue to rotate, the distributed charges are carried on the
sectors to the collecting combs, where they are distributed to the
discharging rods.  At any instant there are thus four pairs of sectors
engaged inductively, two pairs being covered by each neutralizing rod.
  As the plates continue to rotate, a cumulative reaction takes place,
the sectors of each plate acting alternately as inductors, the charges
thus increasing in strength until leakage dissipates the accumulation or
the charge is conducted away by the collecting combs.  If the collecting
combs are removed the charges will still be produced, but then merely
leak away across the plates, which will glow with a luminous discharge.
The reason that the machines will excite at starting is probably due to
an uneven electrostatic condition permanently existing, by which some of
the sectors are in a different state of charge to the others; but the
action of these machines is not at present entirely understood.

  Collecting Points.  Unless the collecting points are exactly alike and
at the same distance from the plates, the action of the machines is
affected and electricity may be only collected from one disc, the other
not contributing to the collected charges for the time being.  Positive
electricity is collected at one comb and negative at the other;
these signs remain constant, the polarity not reversing during the rotation
of the plates.  If, however, a fixed glass plate is placed between the
rotating plates, the polarity reverses at regular intervals;
This is called an alternating Wimshurst machine.
  To increase the output, two, three, or more pairs of plates may be
combined in one machine, each successive pair being a repetition of the
construction of the first pair, all being carried upon the same supporting
spindle and contributing to one pair of discharging rods.
  
  Leyden Jars.  If Leyden jars are connected to the collecting combs, the
inner coatings to the combs and the outer coatings to earth, these jars
will become charged, the result being that a thicker spark at less frequent
intervals will occur between the discharging balls, according to the
capacity of the jars. Without jars the machine gives its maximum length
of spark, which is of thin character and at more frequent intervals.

  Uses. Wimshurst machines are used for illuminating vacuum tubes to
produce X-rays or give effects of discharge in vacua, taking the place
of an induction spark coil in this respect.  They are also used for
electro-medical treatment, and wireless telegraphic experiments.
  The machine should be arranged to suit the conditions of working when
required for a particular purpose.  Though comparatively unaffected
by atmospheric conditions, a dry atmosphere is desirable.
  When used for electro-medical treatment, or production of X-rays,
the wires conducting the electricity to the tube or apparatus are not
connected directly to the discharging rods, but to a pair of discharging
balls which are mounted upon insulated supports.  These balls are placed
near to the discharging balls of the machines, and a spark discharge is
allowed to pass over the intervening air-space between the respective balls.
Such an arrangement is called a spark gap.. The object is to equalize
the rate of discharge and prevent the electricity leaking to earth from
the machine, as will occur if the conducting wires are connected directly
to the discharging rods.
  Wimshurst machines are also called influence machines, a term which
includes others, such as the Voss and Holtz, etc.; all these act by
electrostatic induction, differing in this respect from machines in
which electricity is produced by rubbing action.