the Dead Escapement for Clocks. - 337 
be exactly the same size, and in depth half the thickness of the 
piece. The two circular pieces, Figs. 1 and 9, being of equal 
thickness, and the sinks each equal to half the thickness of the 
piece in which it is turned, it necessarily follows that, when 
the surfaces of the two sinks are brought together, they will 
equal in thickness the remaining part of either piece. That 
this should be the case is indispensable to the correct perform- 
ance of a jointed pallet-frame, made on this construction. Per- 
haps the best mode in practice to make the sinks equal, is to 
turn a piece of brass as a gauge, to let into the pieces, Figs. 1 
and 9, which will ensure the sinks being in every respect the 
same. The section of such a piece is shewn, W, Fig. 10. Ex- 
actly half the pallet-frame is formed out of each of the pieces, 
Figs. 1 and 9, and the two halves are represented Figs. 11 and 
12, and the two put together are represented Fig. 13. To 
strengthen the long arms that carry the pallets, there is to each 
half of the frame a portion of the original piece left concentric 
to the sink, which forms a connexion between the upper sur- 
faces of the long and short arms; and to strengthen the long 
arm it is continued a little below the arm. By this means the 
strength of the frame is greatly increased, and the fitting to- 
gether of the two arms does not entirely depend on the good 
fitting of the holes through their centres, on the steel cylinder, 
or verge, that passes through the common centre of the two, 
This is shewn more plainly in Fig. 11, than in Fig. 12, the 
whole surface of Fig. 12, being on the side represented in the 
figure on one plane, whereas in Fig. 11, (on the side represented 
in the figure,) the two arms and connecting part are on one 
plane, and the sunk part represented by the complete circle on 
another, half the thickness of the piece below the upper plane, 
The manner of fixing the pallets to the axis of the verge con- 
necting the two arms together, and opening and closing them, 
is represented in front, Fig. 15, and in profile, Fig. 14.. A A, 
Fig. 14, is part of the verge, to which is immovably fixed the 
collet C, with a long socket ; D is the pallet-frame, and Ga 
collar in front of the frame. These parts are held together by 
the two screws X and Y, Fig. 15, which are tapped into the 
Vou. XIV. Z 
