George Jamison, Charing Cross, London, England, c. 1800. Movement net
18"h x 8"diameter, overall with base 22"h x 10.5"diameter.
Two plane anchor escapement with divided lift, i.e. the two pallets are in
different planes relative to each other. One half second pendulum with
engraved silvered Earth globe as the bob. Rack and
pinion striking on the hour. Two train chain fusee, with Harrison
maintaining power, eight day duration. Silvered chapter rings and fire gilt
ormolu decorations and
A view of the ormolu molding surrounding the apex dial. Notice the small
moon. It is difficult to see in the photo, but it has a light and dark set
of hemispheres. That moon's rotation gives the phases the moon also
known as a 'Halifax moon'. But what makes this example even more interesting
is that the moon also circles around the center arbor to indicate the age
against the inner dial ring marked 1 though 29 1/2.
The small calendar indicator apertures for day, month and date.
Notice how the strike components, in this view the strike rack and pawl,
are spring biased. In a conventional movement equipped with rack striking
this is accomplished via gravity, but in a horizontal configuration these
parts need the bias of the leaf springs.