424 GEOMEITs-T. 



those parts into quarters ; on B, as a centre, transfer ttie 

 divisions of the arc to the chord B E, which, marked with 

 the corresponding figures, will be a line of rhumbs. 



4. To const ruct the Line of Sines:^'' 



Through each of the divisions of the arc AD drav/ 

 right lines parallel to the radius A C ; and C D will be 

 divided into a line of sines, which are to be numbered 

 from C to D for the right sines ; and from D to C for 

 the versed sines. The versed sines may be continued to 

 180 degrees, by laying the divisions of the radius CD from 

 C to E. 



5. 7*5 construct the Line of Tangents, 



^' 



A rule on C, and the several divisions of the arc A T), 



will intersect the line D G, which will become a line of 

 tangents, and is to be figured from D to G with 10, ao, 



30, 40, &c. 



6. To construct the Line of Secant. 



The distances from the centre C to the divisions on the 

 line of tangents, being transferred .to the line CF from the 



centre 



* For De^nltions of Sines, Tangents and Secants, see PlXns 

 Trigonometry ; and for that of Rhambsj-see N-avigation. 



