575 
M. Jurgensen’s Escapement. 
The third of Mr Gordon’s improvements, which is applicable 
to steam-packets and other vessels, is to surround the ship or 
vessel at about the height of the gunwale with a chevaux-de- 
frise or line of railing, which is to be very thickly set with pikes 
(like a hedge-hog’s back) ; and to prevent any accidents, from 
objects falling upon the sharp points, iron rods and an iron- 
netting might be placed round the chevaux-de-frise. This che- 
vaux-de-frise or assemblage of pikes might be made in a num^ 
ber of separate pieces, so as to be bolted, or otherwise fixed, on 
the outside of the ship when it goes to sea. By this means no 
serious injury would be done by large waves coming on board 
a vessel, or the ship would not be in danger of being pooped, 
although no dead-lights were employed : at the same time, it 
would be a sufficient protection to cabin-windows, for it is only 
when water is kept in a compact body that it is so very power- 
ful ; the instant that its particles are separated and intermixed 
with air, which is a compressible substance, its great power is 
destroyed. 
8. Notice respecting the Escapement of M. Jurgensen. 
In our last Number, p. 148. we have given an account of the 
escapement proposed by M. Jurgensen, but without any en- 
graving of it, as the author had not annexed any to his first 
paper. M. Jurgensen has, however, given an engraving of his 
escapement in a subsequent paper, which we have copied in 
Plate V. Fig. 8. and 9. 
Fig. 8. is a plan, and Fig. 9* a profile view of it, where 
a is the impulse-wheel, c the circle of the escapement, and, h the 
wheel which produces the pause, eer the detent-spring, pressing 
by its elasticity against the fine point of the screw m, and car- 
rying a pallet upon which the teeth of the wheel b rest du- 
ring the vibrations. The spring is in the same plane as the 
circle or roller vs^ which carries a ruby pallet s . — See Shu- 
macher'^s Astrojiomische Nathrichtefi^ No. 14. p. 210. 
B b 2 
