C ill ) 
Secant / but in the ninth Figure ; being leg than it in that 
proportion. The next ftep being ^Il^l will be equal to 
the Cube of the Secant of the middle Latitude multiplied into 
2 s s s 
— -—= 0,00000000705152908715; which therefore uniefi 
the Secant exceed ten times Radius, can never amount to i 
in the fifth pkce. Thefe two fteps fuffice to make the Me- 
ridian Line or Logarithm Tangent to far more places than 
any Tables of Natural Secants yet extant, are computed to; 
but if the third ftep be required it will be found to be 
2 i f 
into -^—4 = 0,00000000000000008^498; By all 
which it appears that Mr. Wright's Table does no where ex- 
ceed the true Meridian Parts by fully half a Minute | 
which finall difference ariles by his having added continu- 
ally the Secants of i',2',3', &c. inftead of o|',ij,2'f, ?'|,6cc. 
But as it is, it is abundantly fiifficient for Nautical XJfes. That 
in Sr. Jonas MoorsNew Syfiem of the Mathematicks is much 
nearer the Truth, but the difference from Wrighf is fcarce 
fenfible, till you exceed thofe Latitudes where Navigation 
ceafes to be pradicable, the one exceeding the Truth by 
about half a Minute^, the other being a very fmall matter 
deficient therefrom' 
For an exarnple eafie to be imitated by whoib pleafes, I 
have added the true Meridional Parts to the firft and laft 
Minutes of the Quadrant y not lb much that there is any 
occafion for fiich accuracy, as to fhew that I have obtained^ 
and laid down herein, the full DoBrine of theie ffiral Rhumbs 
which are of fo great concern in the Art of Navigation. 
Tbe:iicft Minute is, i.oooooooi4io265*862 178 
The Second, 2,00000005641065806707 
TheLaft,or 89*. y9' is 30374,96345 1141422864J 
and not 52 548, 5*279 as Mr. Wright has it, by the addition of 
the decants of every whole Minute: Nor 50249,8 as Mr. 
(^ghtred's Rule makes it, by adding the. Stecants of every 
Qther half Minute. Nor 50564,5 as Sir Jonas Moor had con. 
eluded it by I know not what method, the' in the reft of his> 
Table he follow Oughtred. An^ 
