( 4*1 y 
tc ner, and on their comparing Notes, they have found 
u a Knot Difference ; fometimes it has been more, and 
“ at others lefs, which muft certainly make a ftrange 
“ Confufion in the Reckoning. Under this Head l 
M take leave to obferve, that when the Log is hove, 
“ it is fometimes in fo ftrong a Gale, that the Ship 
“ runs 9 Knots j but before it is hove again, there 
“ may be fuch a Decreafe of the Wind, that for half' 
“ of the Hour fhe may not run above 5 Knots. Her 
true Diftance failed then, is the Mean between the 
Extremes of 9 and 5 • but this has been fo far from 
being coafider’d by fome Chalkers of the Log-board, 
46 that it is but too well known, the Extremes have 
“ been put for the Mean, and the contrary. Were 
“ there Truth in the Log , two Ships in Company 
“ would nearly have the fame Account j but it is 
“ otherwife j for we too often find many Leagues Dif- 
“ ference in Reckonings, even on board the fame 
'* Ship. In a word, fuch Errors have been found in 
ic the Log by fome of my Acquaintance, that when 
* they have failed between a Meridian and a Parai- 
“ lei, the whole Difference on the Log-board has not 
“ prov’d Differejice of Latitude enough to agree with 
“ their Obfervation , although each Day they had a 
<c good obferv’d Latitude, and no Currents. 
“ In the Marine Surveyor we are fo allured of the 
« Ship’s Diftance, that all Ships (hall agree which are 
« in Company, as to their Reckonings, fave that fome 
« Allowance be made for Difference of Judgment in 
« the feveral Perfons who keep Journals. 
There are feveral other Cafes equally, if not more 
momentous than what I offer here, wherein the Ma- 
rine Surveyors ill be found to have the Preference of 
the Log •, but 1 forbear to mention them, chufing ra- 
ther to entertain you with undeniable Proofs of the 
N n n 7 Ufe- 
