Nm 
230 Kchial of a Degree of the Terrestrial Meridian. 
(14, After what we have said of the superiority of the method 
founded Aa lunar observations, it might be expected that we should 
er 
adopt ae 05 for « ; but we are not assured that a sufficient numb 
of observations have yet been applied, to entitle this value to be re- 
ceived ; besides, we are deterred by the opinion of Dr. Bowditch, 
than whose opinion none commands greater deference from all who 
are acquainted with the splendid monument, which the American 
mathematician has recently erected to his own genius, in his transla- 
tion of the Mécanique Céleste ; a translation for which one ought to 
be the more grateful, since, with the help of the translator’s numer- 
ous addenda, it is comparatively easy to understand the modus ope- 
randi of treating the great questions of physical science embodied in 
the original work of the immortal Laplace. From an elaborate ex- 
amination of the figure of the earth, Dr. Bowditch concludes that 
301 Measures the oblateness more nearly than any other fraction, 
and that the corresponding value of the semi-equatorial diameter is 
3963 miles, and the semi-polar diameter 3950 miles very nearly. 
‘These values for « and a, being placed in formula (4) will give us 
68.70859375 miles 
b= bX 0.006633256 (5). From this we have calculated 
the following table, in which columns A contain the latitudes, and 
columns B the lengths of the corresponding degrees, having their 
middle points at the latitudes given in the table; the latitudes being 
expressed in degrees, and the values of L in English miles. 
Table of the Length of the Siw = the Terrestrial Meridian. 
A 
B 
miles. 
45 69. ‘051873 60) 69. "324539 15 | «sl eotttias 
46 
| 69.396889 
39.213984 74 69.315177) 89 | 69.897746 
1563. 754413 [30 68.879873! 45 69.0518731601s9.224539175 69.251413190 (69.397594 
————____—_ a ee Te near a ae siiasiuaellt 
