Il. 
Al Table of the Longitude and Altitude of the Nonagesimal Degree, 
in 42° 23! 28” of North Latitude (the Ellipticity of the Earth being 
assumed to be =~~th, and the Obliquity of the Ecliptic 23° 27’ 40’), 
Sor every Minute of the Right Ascension of the Meridian, — With 
the Corrections of the Table for a Decrease of 100” in the Ob- 
liquity, and of 1000” in the Geographical Latitude. 
By R. T. PAINE, Esa. 
THE corrections were computed for a decrease of 100” in Obliquity, and 
1000” in geographical Latitude ; for an increase, the signs of the corrections 
must be reversed. 
By a decrease in either Latitude or Obliquity, the Longitude is increased 
if the Right Ascension of the Meridian is between six hours and eighteen 
hours, and diminished if between eighteen hours and six hours. 
By a decrease in the Obliquity, the Altitude is increased, if the Longitude is 
between 180° and 360°, and diminished if between 0° and 180°. 
By a decrease in the Latitude, the Altitude is increased. 
*,* ‘The Right Ascension of the Meridian is the sum of the Apparent time 
at the place (reckoned according to the manner of astronomers), and the Sun’s 
Right Ascension ; ov of the Mean time, reckoned in the same manner, and the 
Sidereal time. 
Exampue. 
What was the Longitude and Altitude of the Nonagesimal, in Boston, in Lati- 
tude 42° 20’ 38.1 North, January Ist, 1831, at 6% 22™ 9*.8, A, M., Mean 
time, or reckoned astronomically, 1830, Dec. 31st, 18 22™- 9*.8, the Side- 
real time being 18" 41™ 24*.64, and the Obliquity 23° 27’ 32/.0? 
The A. R. of the Meridian is consequently 13 3™ 34.44. 
Longitude. Altitude. 
fe) / Mt fe) / “ 
At 13%. 3™- 173 21 42.9 45 52 21.4 
Proportion for 344 seconds We Bio — 3 24.4 
Correction for — 170” in Lat. 2 655 + 2.23.3 ° 
Correction for — 8” in Obliq. 7.7 _ 0.9 
Sum 2 : : : 173 31 28 45 51 20 
