_Key Experiments_ (Vol v., pp. 152. 293.).--In an edition of _Hudibras_
of 1704 appears the following "annotation" to the line "As Friar Bacon's
noddle was:"--
"The tradition of Friar Bacon and the Brazen-head is very commonly
known, and considering the times he lived in, is not much more
strange than what another great philosopher of his name has since
deliver'd of a ring that, being ty'd in a string, and held like a
pendulum in the middle of a silver bowl, will vibrate of itself,
and tell exactly against the sides of the divining-cup the same
thing with, Time is, Time was, &c."
I have tried this experiment with the ring, and find the oscillation
takes place as described by AGMOND with the shilling. If, however, the
thread is tightly pressed between the finger and thumb, the vibration
ceases. This latter circumstance appears to support AGMOND'S idea, that
the motive power is due to the pulse, the circulation of the blood
ceasing by pressure.