1815.] ensuring the Altention of Watchmen. 419 
circle are reversed in the order in which they stand on the common 
clock faces, because the motion of the hours becomes reversed by 
making the dial revolve instead of the hands. The register is 
composed of three distinct parts: a light brass circular magazine, 
half an inch wide, and of the same depth, divided into 12 com- 
partments; a lid or cover with the same number of elliptical perfora- 
tions; and an hour circle. Fig. 4 shows the hour circle, to the outer 
rim of which are attached three crutches, J, 4,1, to receive and 
support the magazine, which is guided into its place, and kept 
steady there, by six small shoulders or projections, c, c, c, on its 
inner edge, which embrace the sides of the crutches. Fig. 3 re+ 
presents the magazine or outer circle, with its front plate removed, 
exhibiting the division intocompartments. The partitions are made 
by two or three wires rivetted or screwed into the two sides of the 
circle. Fig. 2 is a front view of the register with all its parts con- 
nected: c, ¢, c, are three studs or buttons which keep the lid 
affixed to the magazine. In this view are shown the elliptical 
openings into the magazine. These openings are 10 minutes in 
their shortest, and 20 in their longest, diameter. The rim moves 
so easily in and out of the crutches, as to admit of its being de- 
tached, or put on, without affecting the going of the clock. Im- 
mediately above the meridian of the clock, fig. 1, a hole, a, is 
bored through the wooden door, of a diameter equal to 10 minutes 
measured on the register circle. The centre of this hole must 
exactly coincide with the centre of the openings in the rim of the 
register. It only remains to furnish the watchman with a sufficient 
number of light spherical wooden balls of a diameter equal to the 
holes in the clock front, and to instruct him to drop one into the 
hole, a, at each hourly visit. The elliptical shape of the holes in 
the face of the rim will allow the ball to pass into the register either 
five minutes before or five minutes after the exact hour stroke. At 
the ezpiration of the watch, the door is unlocked, the rim removed 
from the crutches, and the face or lid slipped from the studs. The 
absence or presence of a ball in each compartment indicates the 
regularity or the neglect with which the duty has been performed. 
i ° 
Reference to the Plate. 
Fig. 1, the head of the clock with the register adapted ready for 
use. 
Fig. 2, the hour and register circles in working order. 
Fig. 3, the register without its plate or eover. 
Fig. 4, the hour circle with the crutches ready to receive the 
register, fig. 3. 
Fig. 5, a section in perspective of fig. 2, fixed to the hour arbor, 
d, of the clock, as in fig. 1. 
Fig. 6, one of the crutches attached to the hour circle, fig. 4, 
and which carry the register, fig. 3. 
2pD2— 4 
ee 
