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MINUTES OF PROCEEDINGS OF 
very high—which is inconvenient, and otherwise objectionable. In 
point of strength, the wagon should, as regards the material of which 
it is constructed, and the scantling of the various parts, be able to 
support with safety its given load, and to take it without breaking 
down over a bad as well as a good road, or even across a small ditch, 
or other obstacle. 
Now, the form of the fore carriage, and the manner of its connection 
with the hind carriage or body, influences to a very considerable degree 
the capability of the wagon to pass obstacles without hurt. For 
example: the fore carriage first meets any obstacle or rut to be passed, 
and in crossing it, rises and falls or falls and rises, while the hind 
carriage is still on the original level. This action necessarily throws a 
strain upon the connecting arrangement of the fore and hind carriages, 
as well as upon their surfaces of contact, to be repeated when the hind 
wheels arrive at the same obstacle. In most wagons, the connection 
between the fore and hind carriages is by a long vertical main pin; and 
the surfaces of contact, wheel plates or otherwise, are at some distance 
around or in front and rear of the point of connection. This being the 
case, it is evident that the strain in question will be less in proportion 
as the distance from the main pin or point of connection to the surface 
of contact is decreased, and also as the play of the pin is increased. 
(The strain upon the pin itself will, of course, increase with the amount 
of play allowed to the pin). Thus, the more nearly the bearing surfaces 
of the fore and hind carriages approach to unite in one point—as they 
do in a limbered wagon—and the more play there is at the point of 
connection—as in the description of wagon just named—the more 
strong will the wagon be for passing broken ground. 
To reducing the bearing surfaces in an ordinary wagon— i.e., one 
without limber—to one point, there are, however, objections; namely, 
that so doing decreases the stability, and under certain circumstances 
admits of the likelihood of the wagon body being much strained. 
Stability. 
The next essential quality in a wagon is stability; that is to say, a 
wagon should not overturn when tilted sideways through a considerable 
angle. As has just been stated, having the hind carriage bearing upon 
the fore carriage at only one point decreases the stability; because then 
the base formed by joining the bearing points of the body is a triangle 
outside of which the vertical through the centre of gravity will soon 
fall, supposing the carriage to be gradually tilted over; and of course, 
as soon as this happens, the wagon upsets. 
We have, however, already seen that one bearing point between the 
fore and hind carriage makes a wagon much better adapted for going 
over rough ground. From this, and what has just been said about 
stability on three bearing points, it would appear that great stability, 
and at the same time perfect construction as regards strength, are 
incompatible, but that one quality must be more or less sacrificed to 
the other, unless the wagon be made of the form of a limbered wagon, 
similar to a field gun-carriage or gun ammunition wagon. 
