WHEEL. 
verge in tlie same proportion. Cylindrical 
wheels, that is, such as are not dished, 
would answer, provided the carriage were 
always on a perfectly horizontal plane ; 
but they would subject the nave to be 
loaded with mud, and pinch the load when 
consisting of light articles rising above the 
body of the carriage. 
The spokes should be set so far from the 
outer end of the nave, that a perpendicular 
from the sole to the under side of the axle 
may fall, between an inch, and two inches, 
betrveen the bushes. By this, the pressure 
will be somewhat greater on the outer than 
on the inward bush, when the wheels are on 
a level. This ought to be so ; for the inner 
part of the axle arm being much bigger 
than the outer, it has more friction ; there- 
fore should have less pressure ; besides, 
every sinking of the wheel, more than the 
other, causes it to pinch the inner bush. The 
best mode of placing spokes in the naves, is 
to mortice them in two rows, alternately ; 
this does not weaken the centre so much as 
when all the spokes are in one row, or 
band, and gives a greater degree of re- 
sistance outwards. The tire, or iron bind- 
ing of a wheel must be so laid on, whether 
in one or more bands, as to form the fi n.s- 
truni of a cone ; but in heavy waggons it is 
usual to make the middle of tlie tire rise 
considerably, so as to bear the whole 
weight on hard roads, whereby the carriage 
will move lighter than if the frustrum were 
rectilinear ; this form likewise causes stones, 
&c. to slip aside ; but in soft soils it is apt 
to occasion much sinking. The axle arm 
should be taper, in order that it may give 
the wheel ratlier a disposition to slide off ; 
otherwise it w'ould be apt to close in- 
wardly, and create excessive friction ; 
hence the necessity for good iron wasters 
exteriorly, and substantial linch-pins. There 
is a common practice of setthig the wheels 
forward ; that is, giving them a slight in- 
clination towards each other, whereby they 
are perhaps an inch nearer at their front 
than at their backs ; this is done to make 
the wheel run more even on its sole, or 
bearing part, and to prevent its gaping for- 
ward ; but it is evidently a distortion which 
prevents the wheel from running exactly at 
right angles with the transverse section of 
the carriage. The nave of a heavy wheel, 
that is for our ordinary cart for field pur- 
poses, need not be more than twelve or 
fourteen inches in length ; if too short, the 
wheel will wabble, unless fitted very tight 
on the axle ; while too long a nave is apt to 
catch the dirt from the upper part, and to 
project too much beyond the outer face of 
tlie fellies ; the above length is exclusive 
of the pan at the outer end. 
The proportions of wheels must be esti- 
mated according to tlie purposes to which 
they are to be applied ; thus waggons 
have in genera! large hind-wheels, while in 
timber carriages the four are usually of the 
same height, or nearly so; the London 
common stage carts have large wheels, 
while the drays used by brewers have very 
low ones. The reason is obvious ; waggons 
and carts load behind ; but timber car- 
riages and drays load at the sides, there- 
fore, in such, large wheels, however much 
they might favour the draught, would be 
extremely inconvenient ; indeed incom- 
patible. Wheels, whatever their size, should 
be made of well seasoned tough wood, pei- 
fectly free from blemish ; the naves are 
generally of elm, the spokes of oak, and the 
fellies of elm, or of ash ; such are found to 
answer best for all carriages attached to 
the ordnance department ; in which the 
following are considered as the regular 
standard heights. 
All the horse-artillery carriages, limbers, 
and waggons ; the heavy six-pounders, and 
long tUree^pounders, and their limbers ; 
the carriage of a six-pounder battalion 
gun ; of a light hve and a half inch howitzer ; 
and the hind wheels of an ammunition wag- 
gon, five feet. The limber to a light six- 
pounder, and five and a half inch howitzer ; 
the carriage of a medium twelve; pounder, 
four feet eight inches. The limber of the 
latter four feet six inches. A sling-cart, 
five feet eight inches. The fore-wheels of 
an ammunition waggon, four feet. A pon- 
toon carriage has the fore-wheels three 
feet, and the hind ones five feet six inches. 
The carriage of an eight inch howitzer, five 
feet the limber, four feet. A ball ammu-1 
nition cart, five feet. 
We are disposed to recommend these 
proportions to the consideration of readers 
concerned in the construction, or in the use 
of wheel carriages ; they being the result of 
innumerable experiments, submitted to une- 
quivocal proof under every variety of locality 
and of burthen. We think it necessary, at 
the same time to observe, that a correspon- 
dent of the Agricultural Magazine, formerly 
published by Longman, Hurst, Rees, and 
Orme, of Paternoster-row, has, in the ele- 
venth number of that work, given, what 
appears to be, an excellent rule for the 
proportions of wheels in waggons. It would 
