not only is that type period, it is recognized as frontrunner for the first
truly mechanical only movement.

The man who was to be come Pope Sylvester II had what is acknowledged as
the first completely mechanical clock in 996 CE, and it supposedly had this
radial pin design.  But that is all buried in my notes as to the quote

However, to give you the reference you are desperately seeking:

1327 CE - Richard of Wallingford ("Tractus Horologii Astonomici") wrote on
a tower clock he built for the Abbey St. Albans that it had a "strobe
escapement", two wheels on the same axle with alternating radial teeth/
verge suspended BETWEEN them, with a short cross piece oscillating as the
wheels rotated past. (no currently known period examples exist, primarily
because they lost as much as several hours a day, and were quickly changed
over in the 1600s to the vertical pendulum because those lose only minutes
a day.

Part of the problem is that a) the first treatise on clock making wasn't
until 1364 when the son of a clockmaker expounded upon his father's work,
and b) as stated above, they were all changed over to the vertical pendulum
in the 1600s.

So,Good Master, since I seem to have gotten you hooked,  your other
research terms should include "escapements" and, oddly, "engines".

The best site I found, however, was .  Full out presentation on
the subject. I can give you more if you like, but that is the mother lode.


On Thu, Aug 1, 2013 at 1:41 AM, Miklos.Farma <[log in to unmask]>wrote:

>  You want to read this book:
> Shaping the Day: A History of Timekeeping in England and Wales 1300-1800,
> by Paul Glennie and Nigel Thrift
> It has a rather large section on the verge and foiliot designs, and a
> number of very good sources.
> Miklos
> On 8/1/2013 12:58 AM, Jerry Harder wrote:
> I have been doing some research on clock escapements.  Turns out pendulum
> escapements aren't period by about 65 years.  Verge and foliot with a crown
> wheel where the pallets engage with opposite sides of the crown wheel are.
> There are some verge and foiliot escapement designs which have 2 gears with
> pins that replace the crown wheel and the pallets both engage the top of
> these two pin gears.  I am looking to prove or disprove weather this type
> is also period.  Any help would be appreciated.  A simple search on firefox
> gives a great overview on wickipedia, and
> shows the two pin-wheeled type.