I 



ft 



OR, PLAIN 



TEACHING. 



45 



crooked line is one that bends, 11, 

 U irregular- 

 ly. Paral- 

 23L lellines,12, 

 are such as are equally distant 

 12 from each 



— — other in all 



their parts. 



m Crooked pa- 



rallels, 13, are lines which, though 

 crooked, are at equal distances 

 13 u 



233. 



234.. 



from each other in all their parts 

 Curved parallels, 14, are lines 

 regularly curved, and equi-dis- 

 tant in all their parts. Cir- 

 cular parallels, 15, are cir- 

 cular lines equi-distant from 



each other. The circumference, 16, 

 of a circle, or of any round body' 

 is the greatest distance round 

 it. ^ The centre of a circle is that 

 point in its middle from which 

 the line of the circumference is 

 equally distant in all parts. The 

 diameter, 17, is the distance 

 through or across a circle, in dis- 



18 



237. 



tinction from the circumference, 

 which passes round it. Angles, 18, 



are the spaces between two lines 

 that meet each other at one of 

 their extremi- 19 

 ties. A. per- 



pendicular ^ 

 line, 19, is a 



line running § 

 straight up, or ^ 

 down. Ahori- m HorixoTilal^ 

 zontalline, 20, ~ 

 is a straight 



line running in a direction across 

 that of a perpendicular line, and 

 inclining neither upwards nor 

 downwards, at either end. A 

 cube, 1, is a regular solid body, 



240. 



consisting of six square and equal 

 sides (of which 1, 2, and 3 may 

 be seen), and are coupled with 

 corresponding sides containing 

 equal angles. A square, 4, has 

 four equal sides and four right 

 angles. 



A square mile of land is a por- 

 tion of land having six hundred 

 $ and forty squares, 



each containing one 

 square acre. The 

 shape of the land 

 need not be square, 

 provided it con- 

 tains an area equal 

 to the number of 

 square acres. Thus, 

 three square miles 

 may be an oblong 9 

 5, or any other form of an equal 

 surfece area ; nine square miles 9 6, 



241. 



