( 4 °° ) 
In a Word, Geography may, by fuch an Expedient, ar- 
rive, in a very expeditious Manner, to as great a Degree 
of Perfection, as it is capable of. 
I fhali have finifh’d my Defign in this Letter, when 
I have taken Notice of the Method of determining the 
Degree and Strength of the Wind, from fuch ‘Data re- 
lating thereunto, as are to be found in Sea-Journals * 
which in general is, from obferving how many Knots 
the Veffel goes at the Time of Observation ; which is 
always inferted in the Day-Book or Journal , or, in 
other Words, what Velocity the then has; for the 
Strength of the Wind may, with Exadnefs enough, in 
this Affair, be judg’d of from the Effed it produces, or 
the Motion it communicates to the Ship. It is true, 
there will be fome confiderable Difference in this Re- 
fped, arifing from the Shape and Burthen of the Vef- 
fel : However, as we do not exped a mathematical Ex- 
adnefs in this Article, after a little Ufe and Experience, 
together with comparing the greateft Velocities of dif- 
ferent Ships together, a Perfon may feldom fail of judg- 
ing of the Strength of the Wind, at lead to a fourth 
Part ; that is, if according to the Method you propofe 
in your Invitatio ad Obfervationes Meteorologicas , 
the greateft Winds be exprefs’d by 4, and the lighted 
by Dnity. 
In Oblique Winds , the Strength or Degree thereof 
will not be diredly proportional to the Velocity of the 
Veffel, but mud be correded a little ^ however, there 
will be no Difficulty in this Matter. For fuch as are 
acquainted with the Method of refolving Oblique 
* Towers into Dire 61 ones , may eafily compofe a Table 
of ‘Proportional Parts fuited thereunto. I did intend 
to have inferted fuch a Table ; but I am afraid I have 
