The doors are now made and hinged, and the hollow spaces intended to hold the glasses and blinds are covered in with thin boards, to prevent any foreign matter from getting down into the space, and being a source of trouble to dislodge. In constructing the body the aid of the smith is called in. His services are required to strengthen the parts subjected to great strain, more particularly the timbers forming the construction of the lower portion. All along each side of the body should be plated with iron; this should be of the best brand and toughest quality. It is several inches wide, and varies from ¼ to ¾ of an inch in thickness. This is called the “edge plate,” and is really the backbone of the body, for everything depends on its stability. It should run from one extremity to the other, commencing at the hind bottom bar, on to which it should be cranked, and ending at the front part of the front boot, bottom side. This plate should take a perfectly flat bearing at every point. Great care must be taken in fitting it, for although the plate may be of the requisite strength the absence of this perfect fitting will render it comparatively weak, the result of which will be found, when the carriage is completed and mounted on the wheels, by the springing of the sides, which will cause the pillars of the body to press on the doors, and it will be a matter of great difficulty to open them. In the application of smith’s work to coach-building, it is often necessary to fit the iron to intricate parts while it is red hot, and if due precaution be not taken the wood becomes charred and useless, and in cases where there are glued joints it may cause the loosening or breaking of these joints and other material defects. It is an easy matter to have the means at hand to get over the difficulty. All that is necessary is to have handy some heat neutraliser. One of the commonest things that can be used is chalk, and no smith’s shop should ever be without it. If chalk is rubbed over the surface to which the hot iron is to be applied it will not char or burn. Plaster of Paris is a still more powerful heat neutraliser, and it is freer from grit. A small quantity of the plaster mixed with water, and worked up to the proper consistency, will be ready for use in about two hours. Many smiths will say that they never have any accidents in applying heated iron, but on inquiry the reason is apparent, for it will generally be found that such men use chalk, in order to see that the iron plate takes its proper bearings, thus inadvertently using a proper heat neutraliser. If it were more generally known that the difficulty could be met by such simple means, there would be less material spoilt in the smith’s shop.