160 MACHINE ror MEASURING a 
The machine now propofed will, it is hoped, be free 
from, at leaft, fome of thefe objections. And, although 
it may not be able to afcertain a fhip’s way through the 
fea to a mathematical precifion, yet if it fhould be “found 
to anfwer the purpofe better than any inftrument hitherto 
contrived, it may be admitted as an acquifition to the art 
of navigation. 
This machine, in its moft fimple form, is reprefented by 
Fig. 1, Plate 3. Wherein AB is a {trong rod of iron move- 
able on the fulcrum C. D is athin circular plate of brafs. 
rivetted to the lower extremity of the rod. E an horizon~ 
tal arm conneéted at one end with the top of the rod AB. 
by a moveable joint F, and at the other end with the 
bottom of the index H by alike moveable joint G. His 
the index turning on its centre I and travelling over the 
graduated arch K; and L isa {trong {pring bearing againft 
the rod AB and conftantly counteracting the preflure upon 
the palate D. The rod AB fhould be applied clofe to one 
fide of -the cut water or ftem, and fhould be of fuch a 
length that the palate D may be no higher above the keel 
than is neceflary to fecure it from injury when the veffel 
is aground or {fails in fhoal water. As the bow of the 
fhip curves inward towards the keel M, the palate D will 
be thrown to a diftance from the bottom of the veffel, al- 
though the perpendicular rod, to which it is annexed, lies 
clofe to the bow above; and, therefore, the palate will be 
more fairly ated upon. The arm E fhould enter the bow 
fomewhere near the hawfer hole, and lead to any convenient 
place in the forecaftle; where a {mooth board or plate may 
be fixed, having the index H and graduated arch K upon it. 
It is evident from the figure, that as the fhip is urged 
forward by the wind, the palate D will be prefled upon by 
the refifting medium, with a greater or lefs force accord- 
ing to the progreflive motion of the fhip: and this will 
operate upon the levers fo as to immediately affect the in- 
dex; making the leaft encreafe or diminution of the fhip’s 
way 
