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 http://www.amazon.com/Shaping-Day-History-Timekeeping-1300-1800/dp/0199278202/ref=wl_it_dp_o_pd_S_nC?ie=UTF8&colid=36NTMMOPUZONZ&coliid=I2OPPLIHIHO3IA 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 www.youtube.com/watch?v=7HgAtCn3VUU shows the two > pin-wheeled type.?