1770. ROUND THE WORLD. 201 



fications for every sea officer, the labours of the spe- 

 culative theorist to solve this problem might be re- 

 mitted, without much injury to mankind : neither 

 will it be so difficult to acquire this qualification, or 

 put it in practice, as may at first appear ; for, with 

 the assistance of the nautical almanack, and astrono- 

 mical ephemeris, the calculations for finding the lon- 

 gitude will take up little more time than the calcu- 

 lation of an azimuth for finding the variation of the 

 compass. 



