The mariners magazine, or, Sturmy's mathematical and practical arts containing the description and use of the scale of scales, it being a mathematical ruler, that resolves most mathematical conclusions, and likewise the making and use of the crostaff, quadrant, and the quadrat, nocturnals, and other most useful instruments for all artists and navigators : the art of navigation, resolved geometrically, instrumentally, and by calculation, and by that late excellent invention of logarithms, in the three principal kinds of sailing : with new tables of the longitude and latitude of the most eminent places ... : together with a discourse of the practick part of navigation ..., a new way of surveying land ..., the art of gauging all sorts of vessels ..., the art of dialling by a gnomical scale ... : whereunto is annexed, an abridgment of the penalties and forfeitures, by acts of parliaments appointed, relating to the customs and navigation : also a compendium of fortification, both geometrically and instrumentally / by Capt. Samuel Sturmy.

CASE VI. The Hypothenusal or Distance Sailed, and the Perpendicular or Diffe∣rence of Latitude given, To find the Rhomb or Angle ABC.

IN the foregoing Triangle, there is given the Hypothenusal or Distance sailed, CB 478 Leagu••s, and the Perpendicular or 253 Leagues difference of Latitude, and it is required to find the Angle ABC, and by it the Rhomb.

As the Logarithm of the Hypothenusal CB 478 Leagues	2, 679428
Is to the Right Angle or Radius 90 deg. CAB	10, 000000
So is the Logarithm of the Perpendicular 253 CA	2, 403121
To the Complement Sine of the Rhomb, or Sine of the An∣gle ABC 32 deg.	9, 723693

The nearest Number answering to 9, 723693, is the Sine of 32 deg. which de∣ducted from 90 deg. there remains the Angle of the Rhomb 58 deg. or S. W. b. W. 1 deg. 45 VVesterly.

By the Line of Numbers.

EXtend the Compasses from 478, to the Sine of 90; the same Distance will reach from 253, to 32 deg.

Or, Extend the Compasses from 478, to 253; the same Extent will reach from the Sine of 90, to the Sine of 32 deg, which is the inquired Angle ABC, and the Com∣plement of the Rhomb.