60 Notices respecting New Books. 
counterpoise to the force of gravity towards the planet; for 
unless this equilibrium be effected, the surface of the ring could 
not appear to the inhabitants perfectly horigontal. 
- It has been remarked by Sir William Herschel, that “ the 
ring of Saturn reflects more light than the body of the planet.” 
The natural inference is, that it is formed of materials of greater 
specific density; and it seems advantageous that it should be so: 
for otherwise, on account of its comparative thinness, it could 
not produce an adequate force of gravity perpendicular to its 
surface, which we must suppose essential to its being inha- 
bited. . 
The annularians in their systems of geography can only 
estimate their latitude by the observed altitude of ‘Saturn’s 
pole; for the sun and all the other heavenly bodies have the 
same altitude viewed from every part of the flat surface of the 
ring. As for their longitude, I have not hitherto been able to 
decide how they ascertain it. 
Should the foregoing remarks be thought to merit a place 
in your Journal, the insertion will much oblige, sir, 
Your most obedient servant, 
Noy. 17, 1825. 5 M. Situ. 
X. Notices respecting New Books. 
The English Flora, Vol. Ill. By Sir J. E. Smitn, M.D.F.R.S. 
President of the Linn. Soc., §c. §c. §¢., 1825. 
HERE is a knowledge acquired by practice and expe- 
rience, which carries us much further into an acquaintance 
with sensible objects than the best instruction and informa- 
tion can do. This is a familiar observation when applied 
to such occupations as have to do with an article of trade. 
The farmer for instance, besides the obvious practice of his 
business, has a great deal of knowledge; the result of long 
experience, which is incapable of being communicated, even 
if his vocabulary were richer than it is; and he could no more 
acquaint a pupil with all the rules by which he judges of the 
goodness of his samples of grain, than he could convey to him b 
words an idea of the looks and expressions by which he knows 
his neighbour’s countenance. Thesame thingis seen inother oc- 
cupations. We have beensurprised at the dexterity with which 
a wool-sorter selects from a pack containing different sam- 
ples, at a single glimpse, the locks of wool of the same quality, 
‘while to our unpractised eye there was little or no difference 
among them. It is this empirical knowledge which gives the prac- 
tical tradesman such advantage, and far outweighs the superior 
intellect 
