of Natural Philosophy... 147 
Prop. 133. — - 240,000 - » 238,200* 
Prop. 135. . 5201 5203 
9538 9539 
Props. A, B; 182, Part. III. Qi! : 0”,5+ 
160,000 400,000. 
Prop. 13. To make the demonstration from fig. 10, con- 
sistent, EPL ought to be regarded as a circle in the heav- 
ens; it is therefore improper to place the spectator at P. 
The diagram should have been constructed like fig. 2, with 
a small concentric circle to denote the earth. | 
Prop. 35. Cor. * Hence i it appears that the earth, at the 
winter solstice or Capricorn, is in a as The stu- 
dent wil be apt to infer, ron this made of expression, that 
the t ts mentioned have ‘some necessary connexion. 
But so fer i is this from being true, that the time when the 
earth is in its perihelion is about ten days later than that of 
the winter solstice. ‘The angular motion of the earth in the 
interval (for 1820) is about 9° 50’. 
Prop. 35. Prob. 6... The method of Geding the bearing 
of two soe on the earth’s surface, here described; is 
manifestly erroneous, except when the places are very near 
each other. ann of the problem does not appem ¢ca- 
solution on the artificial glo 
lt vapter it. a Twilight; has undergone several material 
improvements in the last edition. ‘The Cor: to prop. 37, is 
however out of place, and should have been expunged. 
The demonstration of prop. 39, is freed from several theo- 
retical errors 5 — we eae the attempt to vale Fable 
een the sun’s centre an r limb, in an a 
to so much uncertainty as tes sun’s depression at sk por 
mencement of twilight, attended with no advantage 
— — for the additional viet ganas it gives the 
See) 
cemeesrens a Burg? Lunar Tables 
# Pele umbres “‘Astronomie TIl. 142. Philos Trans isis. gh 
Por sest greatest possible li imit at 0",5, he supposes in 
the double parallax does not equal 0”,25, even for Arcturus oe 
It is scarcel bint <2 ‘to Famer 188 Lig when either of the foregoing num- 
are emplo of the 
in calculations, 
corresponding cherstinbt mest gare in the results deduced fromi-thess.. 
