O£0 A METHOD OF CALCULATING 



XVI. 

 A METHOD OF CALCULATING 



THE 



MOON's PARALLAXES 



INf 



LATITUDE and LONGITUDE. 



By Mr. REUBEN BURROW. 



TN the Nautical Almanack for 1781, among other 

 ■** Problems publifhed by authority of the Board of 

 Longitude, there is one for calculating the I^aceof the 

 Nonagefimal Degree; which isexprefsly recommended 

 to Aftronomers as 8 * fuperior to all other Methods for 

 " calculating Eclipfes of the Sun, and Occultations of 

 " the Stars." Now, as a confiderable part of that me- 

 thod is erroneous, and particularly in South Latitudes, 

 and between the Tropics, (which include the raoft of 

 India,) the error may therefore be of confequence; and 

 the more fo, as it is publifhed under the fanction of 

 Dr. Majkelyne, the Aftronomer Royal. I have, there- 

 fore, taken the liberty of giving the following rule to 

 fupply its place; and, in imitation of the methods of the 

 Hindoos, have endeavoured to exprefs it fo plainly, that 

 any perfon may calculate by it without knowing much 

 of the fubject. 



PROBLEM. 



Given the apparent time at any given place ; to find 

 the longitude and altitude of the nonagefimal degree, 

 and alio the parallaxes in latitude and longitude. 



1 .Turn the difference of longitude from Greenwichinto 

 time, andaddittotheapparenttime 3 iftheplacebe to the 



wed 



