WHE 



WHE 



ground to change into chrysales, and 

 arc protected in the soil until the 

 next season, when tiiey come forth in 

 spring. 



Fumigations with sulphur and 

 smoke have been tried durmg the 

 evening to destroy the worms ; the 

 success is, however, only partial. 

 Sprinkling lime and ashes is much 

 better : a mixture of half a bushel of 

 each may be used to the acre. The 

 lime should be water-slacked. After 

 an invasion of those destructive in- 

 sects, the stubble should be burned, 

 the soil ploughed dee[), atul no wheat 

 sown for one or more seasons. Early 

 or late sowing wdl do little towards 

 saving a crop of wheat, for it ap- 

 pears that the midge lives for thirty- 

 nine days. 



The English papers mention an- 

 other insect, tiie Asctus ■puinilarius, 

 which attacks wheat in the same way 

 as the Hessian fly. 



In Virginia, and some other South- 

 ern States, the chinck hug is often 

 destructive. See tliat insect. 



The wheat weevils found in the 

 United States are the Calandra {Cur- 

 cxdw) granaria and oiyzce; they are 

 both readily destroyed by kiln-drying, 

 at 150° to 180- Fahr. A figure of the 

 former will be found in the article on 

 uisects. 



Besides these, other insects are 

 occasionally found in smaller quan- 

 tities, preying on the roots and young 

 stem, but they seldom produce the 

 destruction of the crop. 



WHEEL and AXLE. A common 

 mechanical contrivance for raising 

 weights, especially water from wells ; 

 the advantage is increased by en- 

 larging the wheel and diminishing 

 the axle, but always with a loss of 

 time. The best form for great me- 

 chanical advantage is that represent- 

 ed in the figure. 



WHEELBARROW. A light car- 

 riage driven by a man and moving on 

 one wheel. It is made of stout plank 

 for carrying stone unci earth, and is 

 lighter and larger for the transporta- 

 tion of grain. 



WHEEL PLOUGH. A plough 

 with a wheel in the heel to diminish 

 the friction of the sole. See Plough. 



WHEELS OF CARRIAGES. 

 The wheel consists of lliree parts : 

 the nave, centre, or hub ; the spokes ; 

 and the circumference, or felloes, 

 bounded with its iron tire. The ma- 

 terials may be of iron or wood ; if the 

 latter, elm or white oak is preferred 

 for the nave, white oak for the spokes, 

 and ash for the felloes. The centre 

 of the nave is furnished with an iron 

 box to receive tiie axletree. The 

 wood should be thoroughly seasoned, 

 and the framing of the wheel set to- 

 gether some weeks before the tire is 

 put on. The manner of setting the 

 tire is well known ; it is heated in a 

 brush fire until nearly red hot, and 

 then placed over the felloes and at 

 once chilled with water. It should 

 be so set as to allow the nails used 

 to fasten it to be driven into the 

 spokes. Great improvements have 

 been made in the axle, which is en- 

 closed in iron or of wrought iron : 

 the latest imjirovement is that of sur- 

 rounding it with a system of friction 

 wheels, which lie between the box 

 and axle, and reduce the friction to 

 a minimum. 



The advantage of the wheel is two- 

 fold. " In the first place, they greatly 

 diminish the friction on the ground 

 by transferring it from the circum- 

 ference to the nave and axle ; and in 

 the second place, they serve to raise 

 the carriage more easily over obsta- 

 cles and asperities met with on the 

 roads. The friction is diminished in 

 the proportion of the circumference 

 of the axle to that of the wheel ; and 

 hence the larger the wheel, and the 

 smaller the axle, the less is the fric- 

 tion. Large wheels are, therefore, 

 best adapted for surmounting inequal- 

 ities of the road. There are, howev- 

 er, circumstances which prescribe 

 limits to the height of the wheels of 



8G1 



