Franz, the son of Johann
Joseph and Heloise Reuleaux, was born in Eschweilerpumpe
on 30 September 1829, and died on 20 August 1905 in Berlin.
He married Charlotte Overbeck (1829-1908) on 26 April 1856 in Bonn.
Major Oskar Reuleaux, the author of the Reuleaux
family tress, was their third child.
In December 1999, we received an e-mail from Francis C Moon,
Joseph Ford Professor of Mechanical & Aerospace Engineering, Comell University,
New York, the gist of which was that he was writing a biography of Franz
Reuleaux, and that he would welcome any information that we could provide.
The subsequent correspondence in e-mails from Professor Moon,
together with an article he published in "Comell Engineering" (Spring
1999), and a report he wrote in July 1999 on "The Comell Reuleaux
Collection".added considerably to our knowledge.
Franz Reuleaux was a distinguished mechanical engineer. He taught at,
and was President of, the Royal Technical Institute in Berlin;
he was the author of, in particular, "Der Constructor" and "Theoretical
Kinematics: Outline of a Theory of Machines", the latter being translated
into French, Italian and English; he lectured widely; he served on international
juries and commissions; and he was active in German politics, as it related
to industry and technology, including the formation of a patent system
One of his special interests was in kinematics, i.e. the way in which machines
convert one sort of motion into another - a steam locomotive converting the
reciprocating motion of a piston into the rotation of the driving wheels is
a simple example.- and he developed a symbolic mathematical representation
of the relationships within a machine. He also created in Berlin a
collection of 800 models of mechanisms that illustrated his ideas. By a curious
coincidence, the German company he authorised to manufacture these models
was Gustav Voigt, though I am not aware of any connection with our Voigt
ancestors.
Cornell's interest in Franz Reuleaux is associated with their acquisition
in 1882 of 300 Reuleaux models, of which apparently 219 remain.
There seems to be no comparable collection in existence anywhere else, the
German ones having been mostly destroyed during the Second World War. After
a somewhat chequered history, the Comell models are now on public display,
and it is hoped eventually to be able to display them on the web as a virtual
museum. Remarkably, all but half a dozen are in working order, and only one
shows corrosion.
Franz Reuleaux's name is also commemorated in the "Reuleaux
Triangle", an equilateral triangle in which each side is an arc of a
circle whose centre is at the opposite comer. Current UK 20p and 50p coins
are, in effect, Reuleaux heptangles on the same principle
- straight-sided coins would slide in a coin-operated machine and might stick;
Reuleaux-type coins will roll. "Reuleaux
Triangles" form the basis of the Wankel rotary internal
combusion engine, but the subject is rather too specialised to be described
here (see "Reuleaux"on the internet).
One of the family trees prepared by Major Oskar Reuleaux
has a photograph attached of the Reuleaux family home
in Eschweilerpumpe, "Now", says the caption (written in 1920),
"the Hotel Bitter". On the wall is a plaque with an inscription
"Professor Reuleaux, the famous promoter of German industry,
was born in this house".
REULEAUX
MODELS
Rotary Pump
Gear Pump
Slider Crank Train
Crown-Wheel Escapement
Pin-Wheel Escapement
( from
"Cornell Engineering" - Spring 1999, pp14,15)
Franz
Reuleaux